WO2023108466A1

WO2023108466A1 - Suspension elements for playback devices

Info

Publication number: WO2023108466A1
Application number: PCT/CN2021/138260
Authority: WO
Inventors: Minqiang YANG
Original assignee: Sonos, Inc.
Priority date: 2021-12-15
Filing date: 2021-12-15
Publication date: 2023-06-22

Abstract

An audio transducer assembly includes a frame, a voice coil coupled to the frame, and a suspension element coupled to the frame and voice coil. The suspension element can include a first member having a first end portion coupled to the frame and a second end portion coupled to the voice coil and opposite the first end portion. The first member can include a corrugated portion between the first and second end portions. The suspension element can include a second member having a first end portion coupled to the first end portion of the first member and a second end portion coupled to the second end portion of the first member. The second member includes a corrugated portion between the first and second end portions of the second member. The suspension element can include a negative stiffness along an axis.

Description

SUSPENSION ELEMENTS FOR PLAYBACK DEVICES

FIELD OF THE DISCLOSURE

The present disclosure is related to consumer goods and, more particularly, to methods, systems, products, features, services, and other elements directed to media playback or some aspect thereof.

BACKGROUND

Options for accessing and listening to digital audio in an out-loud setting were limited until in 2002, when SONOS, Inc. began development of a new type of playback system. Sonos then filed one of its first patent applications in 2003, entitled “Method for Synchronizing Audio Playback between Multiple Networked Devices, ” and began offering its first media playback systems for sale in 2005. The Sonos Wireless Home Sound System enables people to experience music from many sources via one or more networked playback devices. Through a software control application installed on a controller (e.g., smartphone, tablet, computer, voice input device) , one can play what she wants in any room having a networked playback device. Media content (e.g., songs, podcasts, video sound) can be streamed to playback devices such that each room with a playback device can play back corresponding different media content. In addition, rooms can be grouped together for synchronous playback of the same media content, and/or the same media content can be heard in all rooms synchronously.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, examples, and advantages of the presently disclosed technology may be better understood with regard to the following description, appended claims, and accompanying drawings, as listed below. A person skilled in the relevant art will understand that the features shown in the drawings are for purposes of illustrations, and variations, including different and/or additional features and arrangements thereof, are possible.

Figure 1A is a partial cutaway view of an environment having a media playback system configured in accordance with examples of the disclosed technology.

Figure 1B is a schematic diagram of the media playback system of Figure 1A and one or more networks.

Figure 1C is a block diagram of a playback device.

Figure 1D is a block diagram of a playback device.

Figure 1E is a block diagram of a network microphone device.

Figure 1F is a block diagram of a network microphone device.

Figure 1G is a block diagram of a playback device.

Figure 1H is a partially schematic diagram of a control device.

Figure 2A is a front isometric view of a playback device configured in accordance with examples of the disclosed technology.

Figure 2B is a front isometric view of the playback device of Figure 2A without a grille.

Figure 2C is an exploded view of the playback device of Figure 2A.

Figure 3A is a block diagram of a playback device in accordance with examples of the disclosed technology.

Figure 3B is a perspective view of a playback device in accordance with examples of the disclosed technology.

Figure 3C is a cross-sectional view of the transducer of the playback device of Figure 3B.

Figure 3D is a perspective view of the transducer of the playback device of Figure 3B with several components hidden for clarity.

Figure 3E is a perspective view of a suspension element in accordance with examples of the disclosed technology.

Figure 3F is a top view of the suspension element of Figure 3E.

Figure 4 illustrates an example method of assembling a playback device in accordance with examples of the disclosed technology.

The drawings are for the purpose of illustrating example examples, but those of ordinary skill in the art will understand that the technology disclosed herein is not limited to the arrangements and/or instrumentality shown in the drawings.

DETAILED DESCRIPTION

I. Overview

Conventional audio transducers often include several suspension components, such as a spider and a surround, which can keep other components within the audio transducer properly positioned. These suspension components have a stiffness, which represents the extent to which each suspension component resists displacement in response to an applied force. Typically, the stiffness value for each suspension part is a positive value, meaning each suspension component resists movement against the direction of the applied force. This property of suspension components is desirable for keeping other components within the audio transducers properly aligned and facilitates the oscillating pistonic motion of the diaphragm during operation.

While the stiffness of the suspension components is beneficial for keeping other components within the audio transducers aligned, this stiffness can have some drawbacks in an audio transducer. For example, the suspension components can decrease the efficiency of the audio transducer, as the audio transducer needs to consume additional power to overcome the transducer’s stiffness from the suspension components to operate.

Examples of the present technology can address these and other issues by utilizing a suspension component with a negative stiffness value. Unlike suspension components with a positive stiffness value, suspension components with a negative stiffness value do not resist displacement, but rather respond with an additional movement in the same direction as the applied force. As a result of this property, components within the audio transducer, such as the diaphragm, can move with less resistance from the suspension components in a sealed enclosure. Thus, these negative stiffness suspension components can decrease the amount of power that is needed to operate the audio transducer, as there is less stiffness to overcome within the system for moving components, like the voice coil.

In some examples, the suspension component couples to the frame and to the voice coil of the audio transducer. Additionally, the suspension component can include one or more members that are compressed when the suspension component is coupled to the frame and voice coil. By compressing these members, the suspension component reduces the amount of stiffness that is needed to operate the audio transducer, and thus, results in a suspension component with a negative stiffness value.

Although compressing the suspension component can result in the suspension component having a negative stiffness value, this compression can create high levels of stress within the suspension component. In some examples, the stress resulting from the compression can lead to the suspension component failing under normal operating conditions.

Examples of the present technology can address these and other issues by configuring the suspension component such that stress is distributed across or throughout the component rather than concentrated in a specific region. In some examples, the suspension component can include one or more corrugated portions. These corrugated portions can distribute the stress from the high stress areas to other areas of the suspension component. In various examples, the suspension component can include one or more narrowed portions. These narrowed portions can also reduce the amount of stress experienced at a particular point along the suspension component. Accordingly, by carefully configuring the suspension component, the suspension component can reduce the stiffness within the audio transducer while also being capable of withstanding the stress experienced under normal operating conditions.

While some examples described herein may refer to functions performed by given actors such as “users, ” “listeners, ” and/or other entities, it should be understood that this is for purposes of explanation only. The claims should not be interpreted to require action by any such example actor unless explicitly required by the language of the claims themselves.

In the Figures, identical reference numbers identify generally similar, and/or identical, elements. To facilitate the discussion of any particular element, the most significant digit or digits of a reference number refers to the Figure in which that element is first introduced. For example, element 110a is first introduced and discussed with reference to Figure 1A. Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular examples of the disclosed technology. Accordingly, other examples can have other details, dimensions, angles and features without departing from the spirit or scope of the disclosure. In addition, those of ordinary skill in the art will appreciate that further examples of the various disclosed technologies can be practiced without several of the details described below.

II. Suitable Operating Environment

Figure 1A is a partial cutaway view of a media playback system 100 distributed in an environment 101 (e.g., a house) . The media playback system 100 comprises one or more playback devices 110 (identified individually as playback devices 110a-n) , one or more network microphone devices ( “NMDs” ) , 120 (identified individually as NMDs 120a-c) , and one or more control devices 130 (identified individually as

control devices

130a and 130b) .

As used herein the term “playback device” can generally refer to a network device configured to receive, process, and output data of a media playback system. For example, a playback device can be a network device that receives and processes audio content. In some examples, a playback device includes one or more transducers or speakers powered by one or more amplifiers. In other examples, however, a playback device includes one of (or neither of) the speaker and the amplifier. For instance, a playback device can comprise one or more amplifiers configured to drive one or more speakers external to the playback device via a corresponding wire or cable.

Moreover, as used herein the term NMD (i.e., a “network microphone device” ) can generally refer to a network device that is configured for audio detection. In some examples, an NMD is a stand-alone device configured primarily for audio detection. In other examples, an NMD is incorporated into a playback device (or vice versa) .

The term “control device” can generally refer to a network device configured to perform functions relevant to facilitating user access, control, and/or configuration of the media playback system 100.

Each of the playback devices 110 is configured to receive audio signals or data from one or more media sources (e.g., one or more remote servers, one or more local devices) and play back the received audio signals or data as sound. The one or more NMDs 120 are configured to receive spoken word commands, and the one or more control devices 130 are configured to receive user input. In response to the received spoken word commands and/or user input, the media playback system 100 can play back audio via one or more of the playback devices 110. In certain examples, the playback devices 110 are configured to commence playback of media content in response to a trigger. For instance, one or more of the playback devices 110 can be configured to play back a morning playlist upon detection of an associated trigger condition (e.g., presence of a user in a kitchen, detection of a coffee machine operation) . In some examples, for instance, the media playback system 100 is configured to play back audio from a first playback device (e.g., the playback device 110a) in synchrony with a second playback device (e.g., the playback device 110b) . Interactions between the playback devices 110, NMDs 120, and/or control devices 130 of the media playback system 100 configured in accordance with the various examples of the disclosure are described in greater detail below.

In the illustrated example of Figure 1A, the environment 101 comprises a household having several rooms, spaces, and/or playback zones, including (clockwise from upper left) a master bathroom 101a, a master bedroom 101b, a second bedroom 101c, a family room or den 101d, an office 101e, a living room 101f, a dining room 101g, a kitchen 101h, and an outdoor patio 101i. While certain examples are described below in the context of a home environment, the technologies described herein may be implemented in other types of environments. In some examples, for instance, the media playback system 100 can be implemented in one or more commercial settings (e.g., a restaurant, mall, airport, hotel, a retail or other store) , one or more vehicles (e.g., a sports utility vehicle, bus, car, a ship, a boat, an airplane) , multiple environments (e.g., a combination of home and vehicle environments) , and/or another suitable environment where multi-zone audio may be desirable.

The media playback system 100 can comprise one or more playback zones, some of which may correspond to the rooms in the environment 101. The media playback system 100 can be established with one or more playback zones, after which additional zones may be added, or removed to form, for example, the configuration shown in Figure 1A. Each zone may be given a name according to a different room or space such as the office 101e, master bathroom 101a, master bedroom 101b, the second bedroom 101c, kitchen 101h, dining room 101g, living room 101f, and/or the balcony 101i. In some examples, a single playback zone may include multiple rooms or spaces. In certain examples, a single room or space may include multiple playback zone s.

In the illustrated example of Figure 1A, the master bathroom 101a, the second bedroom 101c, the office 101e, the living room 101f, the dining room 101g, the kitchen 101h, and the outdoor patio 101i each include one playback device 110, and the master bedroom 101b and the den 101d include a plurality of playback devices 110. In the master bedroom 101b, the playback devices 110l and 110m may be configured, for example, to play back audio content in synchrony as individual ones of playback devices 110, as a bonded playback zone, as a consolidated playback device, and/or any combination thereof. Similarly, in the den 101d, the playback devices 110h-j can be configured, for instance, to play back audio content in synchrony as individual ones of playback devices 110, as one or more bonded playback devices, and/or as one or more consolidated playback devices. Additional details regarding bonded and consolidated playback devices are described below with respect to Figures 1B and 1E.

In some examples, one or more of the playback zones in the environment 101 may each be playing different audio content. For instance, a user may be grilling on the patio 101i and listening to hip hop music being played by the playback device 110c while another user is preparing food in the kitchen 101h and listening to classical music played by the playback device 110b. In another example, a playback zone may play the same audio content in synchrony with another playback zone. For instance, the user may be in the office 101e listening to the playback device 110f playing back the same hip-hop music being played back by playback device 110c on the patio 101i. In some examples, the

playback devices

110c and 110f play back the hip hop music in synchrony such that the user perceives that the audio content is being played seamlessly (or at least substantially seamlessly) while moving between different playback zones. Additional details regarding audio playback synchronization among playback devices and/or zones can be found, for example, in U.S. Patent No. 8,234,395 entitled, “System and method for synchronizing operations among a plurality of independently clocked digital data processing devices, ” which is incorporated herein by reference in its entirety.

a. Suitable Media Playback System

Figure 1B is a schematic diagram of the media playback system 100 and a cloud network 102. For ease of illustration, certain devices of the media playback system 100 and the cloud network 102 are omitted from Figure 1B. One or more communication links 103 (referred to hereinafter as “the links 103” ) communicatively couple the media playback system 100 and the cloud network 102.

The links 103 can comprise, for example, one or more wired networks, one or more wireless networks, one or more wide area networks (WAN) , one or more local area networks (LAN) , one or more personal area networks (PAN) , one or more telecommunication networks (e.g., one or more Global System for Mobiles (GSM) networks, Code Division Multiple Access (CDMA) networks, Long-Term Evolution (LTE) networks, 5G communication network networks, and/or other suitable data transmission protocol networks) , etc. The cloud network 102 is configured to deliver media content (e.g., audio content, video content, photographs, social media content) to the media playback system 100 in response to a request transmitted from the media playback system 100 via the links 103. In some examples, the cloud network 102 is further configured to receive data (e.g. voice input data) from the media playback system 100 and correspondingly transmit commands and/or media content to the media playback system 100.

The cloud network 102 comprises computing devices 106 (identified separately as a first computing device 106a, a second computing device 106b, and a third computing device 106c) . The computing devices 106 can comprise individual computers or servers, such as, for example, a media streaming service server storing audio and/or other media content, a voice service server, a social media server, a media playback system control server, etc. In some examples, one or more of the computing devices 106 comprise modules of a single computer or server. In certain examples, one or more of the computing devices 106 comprise one or more modules, computers, and/or servers. Moreover, while the cloud network 102 is described above in the context of a single cloud network, in some examples the cloud network 102 comprises a plurality of cloud networks comprising communicatively coupled computing devices. Furthermore, while the cloud network 102 is shown in Figure 1B as having three of the computing devices 106, in some examples, the cloud network 102 comprises fewer (or more than) three computing devices 106.

The media playback system 100 is configured to receive media content from the networks 102 via the links 103. The received media content can comprise, for example, a Uniform Resource Identifier (URI) and/or a Uniform Resource Locator (URL) . For instance, in some examples, the media playback system 100 can stream, download, or otherwise obtain data from a URI or a URL corresponding to the received media content. A network 104 communicatively couples the links 103 and at least a portion of the devices (e.g., one or more of the playback devices 110, NMDs 120, and/or control devices 130) of the media playback system 100. The network 104 can include, for example, a wireless network (e.g., a WiFi network, a Bluetooth, a Z-Wave network, a ZigBee, and/or other suitable wireless communication protocol network) and/or a wired network (e.g., a network comprising Ethernet, Universal Serial Bus (USB) , and/or another suitable wired communication) . As those of ordinary skill in the art will appreciate, as used herein, “WiFi” can refer to several different communication protocols including, for example, Institute of Electrical and Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ac, 802.11ad, 802.11af, 802.11ah, 802.11ai, 802.11aj, 802.11aq, 802.11ax, 802.11ay, 802.15, etc. transmitted at 2.4 Gigahertz (GHz) , 5 GHz, and/or another suitable frequency.

In some examples, the network 104 comprises a dedicated communication network that the media playback system 100 uses to transmit messages between individual devices and/or to transmit media content to and from media content sources (e.g., one or more of the computing devices 106) . In certain examples, the network 104 is configured to be accessible only to devices in the media playback system 100, thereby reducing interference and competition with other household devices. In other examples, however, the network 104 comprises an existing household communication network (e.g., a household WiFi network) . In some examples, the links 103 and the network 104 comprise one or more of the same networks. In some examples, for example, the links 103 and the network 104 comprise a telecommunication network (e.g., an LTE network, a 5G network) . Moreover, in some examples, the media playback system 100 is implemented without the network 104, and devices comprising the media playback system 100 can communicate with each other, for example, via one or more direct connections, PANs, telecommunication networks, and/or other suitable communication links.

In some examples, audio content sources may be regularly added or removed from the media playback system 100. In some examples, for instance, the media playback system 100 performs an indexing of media items when one or more media content sources are updated, added to, and/or removed from the media playback system 100. The media playback system 100 can scan identifiable media items in some or all folders and/or directories accessible to the playback devices 110, and generate or update a media content database comprising metadata (e.g., title, artist, album, track length) and other associated information (e.g., URIs, URLs) for each identifiable media item found. In some examples, for instance, the media content database is stored on one or more of the playback devices 110, network microphone devices 120, and/or control devices 130.

In the illustrated example of Figure 1B, the playback devices 110l and 110m comprise a group 107a. The playback devices 110l and 110m can be positioned in different rooms in a household and be grouped together in the group 107a on a temporary or permanent basis based on user input received at the control device 130a and/or another control device 130 in the media playback system 100. When arranged in the group 107a, the playback devices 110l and 110m can be configured to play back the same or similar audio content in synchrony from one or more audio content sources. In certain examples, for instance, the group 107a comprises a bonded zone in which the playback devices 110l and 110m comprise left audio and right audio channels, respectively, of multi-channel audio content, thereby producing or enhancing a stereo effect of the audio content. In some examples, the group 107a includes additional playback devices 110. In other examples, however, the media playback system 100 omits the group 107a and/or other grouped arrangements of the playback devices 110.

The media playback system 100 includes the

NMDs

120a and 120d, each comprising one or more microphones configured to receive voice utterances from a user. In the illustrated example of Figure 1B, the NMD 120a is a standalone device and the NMD 120d is integrated into the playback device 110n. The NMD 120a, for example, is configured to receive voice input 121 from a user 123. In some examples, the NMD 120a transmits data associated with the received voice input 121 to a voice assistant service (VAS) configured to (i) process the received voice input data and (ii) transmit a corresponding command to the media playback system 100. In some examples, for instance, the computing device 106c comprises one or more modules and/or servers of a VAS (e.g., a VAS operated by one or more of

) . The computing device 106c can receive the voice input data from the NMD 120a via the network 104 and the links 103. In response to receiving the voice input data, the computing device 106c processes the voice input data (i.e., “Play Hey Jude by The Beatles” ) , and determines that the processed voice input includes a command to play a song (e.g., “Hey Jude” ) . The computing device 106c accordingly transmits commands to the media playback system 100 to play back “Hey Jude” by the Beatles from a suitable media service (e.g., via one or more of the computing devices 106) on one or more of the playback devices 110.

b. Suitable Playback Devices

Figure 1C is a block diagram of the playback device 110a comprising an input/output 111. The input/output 111 can include an analog I/O 111a (e.g., one or more wires, cables, and/or other suitable communication links configured to carry analog signals) and/or a digital I/O 111b (e.g., one or more wires, cables, or other suitable communication links configured to carry digital signals) . In some examples, the analog I/O 111a is an audio line-in input connection comprising, for example, an auto-detecting 3.5mm audio line-in connection. In some examples, the digital I/O 111b comprises a Sony/Philips Digital Interface Format (S/PDIF) communication interface and/or cable and/or a Toshiba Link (TOSLINK) cable. In some examples, the digital I/O 111b comprises a High-Definition Multimedia Interface (HDMI) interface and/or cable. In some examples, the digital I/O 111b includes one or more wireless communication links comprising, for example, a radio frequency (RF) , infrared, WiFi, Bluetooth, or another suitable communication protocol. In certain examples, the analog I/O 111a and the digital 111b comprise interfaces (e.g., ports, plugs, jacks) configured to receive connectors of cables transmitting analog and digital signals, respectively, without necessarily including cables.

The playback device 110a, for example, can receive media content (e.g., audio content comprising music and/or other sounds) from a local audio source 105 via the input/output 111 (e.g., a cable, a wire, a PAN, a Bluetooth connection, an ad hoc wired or wireless communication network, and/or another suitable communication link) . The local audio source 105 can comprise, for example, a mobile device (e.g., a smartphone, a tablet, a laptop computer) or another suitable audio component (e.g., a television, a desktop computer, an amplifier, a phonograph, a Blu-ray player, a memory storing digital media files) . In some examples, the local audio source 105 includes local music libraries on a smartphone, a computer, a networked-attached storage (NAS) , and/or another suitable device configured to store media files. In certain examples, one or more of the playback devices 110, NMDs 120, and/or control devices 130 comprise the local audio source 105. In other examples, however, the media playback system omits the local audio source 105 altogether. In some examples, the playback device 110a does not include an input/output 111 and receives all audio content via the network 104.

The playback device 110a further comprises electronics 112, a user interface 113 (e.g., one or more buttons, knobs, dials, touch-sensitive surfaces, displays, touchscreens) , and one or more transducers 114 (referred to hereinafter as “the transducers 114” ) . The electronics 112 is configured to receive audio from an audio source (e.g., the local audio source 105) via the input/output 111, one or more of the computing devices 106a-c via the network 104 (Figure 1B) ) , amplify the received audio, and output the amplified audio for playback via one or more of the transducers 114. In some examples, the playback device 110a optionally includes one or more microphones 115 (e.g., a single microphone, a plurality of microphones, a microphone array) (hereinafter referred to as “the microphones 115” ) . In certain examples, for example, the playback device 110a having one or more of the optional microphones 115 can operate as an NMD configured to receive voice input from a user and correspondingly perform one or more operations based on the received voice input.

In the illustrated example of Figure 1C, the electronics 112 comprise one or more processors 112a (referred to hereinafter as “the processors 112a” ) , memory 112b, software components 112c, a network interface 112d, one or more audio processing components 112g (referred to hereinafter as “the audio components 112g” ) , one or more audio amplifiers 112h (referred to hereinafter as “the amplifiers 112h” ) , and power 112i (e.g., one or more power supplies, power cables, power receptacles, batteries, induction coils, Power-over Ethernet (POE) interfaces, and/or other suitable sources of electric power) . In some examples, the electronics 112 optionally include one or more other components 112j (e.g., one or more sensors, video displays, touchscreens, battery charging bases) .

The processors 112a can comprise clock-driven computing component (s) configured to process data, and the memory 112b can comprise a computer-readable medium (e.g., a tangible, non-transitory computer-readable medium, data storage loaded with one or more of the software components 112c) configured to store instructions for performing various operations and/or functions. The processors 112a are configured to execute the instructions stored on the memory 112b to perform one or more of the operations. The operations can include, for example, causing the playback device 110a to retrieve audio data from an audio source (e.g., one or more of the computing devices 106a-c (Figure 1B) ) , and/or another one of the playback devices 110. In some examples, the operations further include causing the playback device 110a to send audio data to another one of the playback devices 110a and/or another device (e.g., one of the NMDs 120) . Certain examples include operations causing the playback device 110a to pair with another of the one or more playback devices 110 to enable a multi-channel audio environment (e.g., a stereo pair, a bonded zone) .

The processors 112a can be further configured to perform operations causing the playback device 110a to synchronize playback of audio content with another of the one or more playback devices 110. As those of ordinary skill in the art will appreciate, during synchronous playback of audio content on a plurality of playback devices, a listener will preferably be unable to perceive time-delay differences between playback of the audio content by the playback device 110a and the other one or more other playback devices 110. Additional details regarding audio playback synchronization among playback devices can be found, for example, in U.S. Patent No. 8,234,395, which was incorporated by reference above.

In some examples, the memory 112b is further configured to store data associated with the playback device 110a, such as one or more zones and/or zone groups of which the playback device 110a is a member, audio sources accessible to the playback device 110a, and/or a playback queue that the playback device 110a (and/or another of the one or more playback devices) can be associated with. The stored data can comprise one or more state variables that are periodically updated and used to describe a state of the playback device 110a. The memory 112b can also include data associated with a state of one or more of the other devices (e.g., the playback devices 110, NMDs 120, control devices 130) of the media playback system 100. In some examples, for instance, the state data is shared during predetermined intervals of time (e.g., every 5 seconds, every 10 seconds, every 60 seconds) among at least a portion of the devices of the media playback system 100, so that one or more of the devices have the most recent data associated with the media playback system 100.

The network interface 112d is configured to facilitate a transmission of data between the playback device 110a and one or more other devices on a data network such as, for example, the links 103 and/or the network 104 (Figure 1B) . The network interface 112d is configured to transmit and receive data corresponding to media content (e.g., audio content, video content, text, photographs) and other signals (e.g., non-transitory signals) comprising digital packet data including an Internet Protocol (IP) -based source address and/or an IP-based destination address. The network interface 112d can parse the digital packet data such that the electronics 112 properly receives and processes the data destined for the playback device 110a.

In the illustrated example of Figure 1C, the network interface 112d comprises one or more wireless interfaces 112e (referred to hereinafter as “the wireless interface 112e” ) . The wireless interface 112e (e.g., a suitable interface comprising one or more antennae) can be configured to wirelessly communicate with one or more other devices (e.g., one or more of the other playback devices 110, NMDs 120, and/or control devices 130) that are communicatively coupled to the network 104 (Figure 1B) in accordance with a suitable wireless communication protocol (e.g., WiFi, Bluetooth, LTE) . In some examples, the network interface 112d optionally includes a wired interface 112f (e.g., an interface or receptacle configured to receive a network cable such as an Ethernet, a USB-A, USB-C, and/or Thunderbolt cable) configured to communicate over a wired connection with other devices in accordance with a suitable wired communication protocol. In certain examples, the network interface 112d includes the wired interface 112f and excludes the wireless interface 112e. In some examples, the electronics 112 excludes the network interface 112d altogether and transmits and receives media content and/or other data via another communication path (e.g., the input/output 111) .

The audio components 112g are configured to process and/or filter data comprising media content received by the electronics 112 (e.g., via the input/output 111 and/or the network interface 112d) to produce output audio signals. In some examples, the audio processing components 112g comprise, for example, one or more digital-to-analog converters (DAC) , audio preprocessing components, audio enhancement components, a digital signal processors (DSPs) , and/or other suitable audio processing components, modules, circuits, etc. In certain examples, one or more of the audio processing components 112g can comprise one or more subcomponents of the processors 112a. In some examples, the electronics 112 omits the audio processing components 112g. In some examples, for instance, the processors 112a execute instructions stored on the memory 112b to perform audio processing operations to produce the output audio signals.

The amplifiers 112h are configured to receive and amplify the audio output signals produced by the audio processing components 112g and/or the processors 112a. The amplifiers 112h can comprise electronic devices and/or components configured to amplify audio signals to levels sufficient for driving one or more of the transducers 114. In some examples, for instance, the amplifiers 112h include one or more switching or class-D power amplifiers. In other examples, however, the amplifiers include one or more other types of power amplifiers (e.g., linear gain power amplifiers, class-A amplifiers, class-B amplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers, class-E amplifiers, class-F amplifiers, class-G and/or class H amplifiers, and/or another suitable type of power amplifier) . In certain examples, the amplifiers 112h comprise a suitable combination of two or more of the foregoing types of power amplifiers. Moreover, in some examples, individual ones of the amplifiers 112h correspond to individual ones of the transducers 114. In other examples, however, the electronics 112 includes a single one of the amplifiers 112h configured to output amplified audio signals to a plurality of the transducers 114. In some other examples, the electronics 112 omits the amplifiers 112h.

The transducers 114 (e.g., one or more speakers and/or speaker drivers) receive the amplified audio signals from the amplifier 112h and render or output the amplified audio signals as sound (e.g., audible sound waves having a frequency between about 20 Hertz (Hz) and 20 kilohertz (kHz) ) . In some examples, the transducers 114 can comprise a single transducer. In other examples, however, the transducers 114 comprise a plurality of audio transducers. In some examples, the transducers 114 comprise more than one type of transducer. For example, the transducers 114 can include one or more low frequency transducers (e.g., subwoofers, woofers) , mid-range frequency transducers (e.g., mid-range transducers, mid-woofers) , and one or more high frequency transducers (e.g., one or more tweeters) . As used herein, “low frequency” can generally refer to audible frequencies below about 500 Hz, “mid-range frequency” can generally refer to audible frequencies between about 500 Hz and about 2 kHz, and “high frequency” can generally refer to audible frequencies above 2 kHz. In certain examples, however, one or more of the transducers 114 comprise transducers that do not adhere to the foregoing frequency ranges. For example, one of the transducers 114 may comprise a mid-woofer transducer configured to output sound at frequencies between about 200 Hz and about 5 kHz.

By way of illustration, SONOS, Inc. presently offers (or has offered) for sale certain playback devices including, for example, a “SONOS ONE, ” “MOVE, ” “PLAY: 5, ” “BEAM, ” “PLAYBAR, ” “PLAYBASE, ” “PORT, ” “BOOST, ” “AMP, ” and “SUB. ” Other suitable playback devices may additionally or alternatively be used to implement the playback devices of example examples disclosed herein. Additionally, one of ordinary skilled in the art will appreciate that a playback device is not limited to the examples described herein or to SONOS product offerings. In some examples, for example, one or more playback devices 110 comprises wired or wireless headphones (e.g., over-the-ear headphones, on-ear headphones, in-ear earphones) . In other examples, one or more of the playback devices 110 comprise a docking station and/or an interface configured to interact with a docking station for personal mobile media playback devices. In certain examples, a playback device may be integral to another device or component such as a television, a lighting fixture, or some other device for indoor or outdoor use. In some examples, a playback device omits a user interface and/or one or more transducers. For example, FIG. 1D is a block diagram of a playback device 110p comprising the input/output 111 and electronics 112 without the user interface 113 or transducers 114.

Figure 1E is a block diagram of a bonded playback device 110q comprising the playback device 110a (Figure 1C) sonically bonded with the playback device 110i (e.g., a subwoofer) (Figure 1A) . In the illustrated example, the

playback devices

110a and 110i are separate ones of the playback devices 110 housed in separate enclosures. In some examples, however, the bonded playback device 110q comprises a single enclosure housing both the

playback devices

110a and 110i. The bonded playback device 110q can be configured to process and reproduce sound differently than an unbonded playback device (e.g., the playback device 110a of Figure 1C) and/or paired or bonded playback devices (e.g., the playback devices 110l and 110m of Figure 1B) . In some examples, for instance, the playback device 110a is full-range playback device configured to render low frequency, mid-range frequency, and high frequency audio content, and the playback device 110i is a subwoofer configured to render low frequency audio content. In some examples, the playback device 110a, when bonded with the first playback device, is configured to render only the mid-range and high frequency components of a particular audio content, while the playback device 110i renders the low frequency component of the particular audio content. In some examples, the bonded playback device 110q includes additional playback devices and/or another bonded playback device. Additional playback device examples are described in further detail below with respect to Figures 2A–2C.

c. Suitable Network Microphone Devices (NMDs)

Figure 1F is a block diagram of the NMD 120a (Figures 1A and 1B) . The NMD 120a includes one or more voice processing components 124 (hereinafter “the voice components 124” ) and several components described with respect to the playback device 110a (Figure 1C) including the processors 112a, the memory 112b, and the microphones 115. The NMD 120a optionally comprises other components also included in the playback device 110a (Figure 1C) , such as the user interface 113 and/or the transducers 114. In some examples, the NMD 120a is configured as a media playback device (e.g., one or more of the playback devices 110) , and further includes, for example, one or more of the audio components 112g (Figure 1C) , the amplifiers 114, and/or other playback device components. In certain examples, the NMD 120a comprises an Internet of Things (IoT) device such as, for example, a thermostat, alarm panel, fire and/or smoke detector, etc. In some examples, the NMD 120a comprises the microphones 115, the voice processing components 124, and only a portion of the components of the electronics 112 described above with respect to Figure 1B. In some examples, for instance, the NMD 120a includes the processor 112a and the memory 112b (Figure 1B) , while omitting one or more other components of the electronics 112. In some examples, the NMD 120a includes additional components (e.g., one or more sensors, cameras, thermometers, barometers, hygrometers) .

In some examples, an NMD can be integrated into a playback device. Figure 1G is a block diagram of a playback device 110r comprising an NMD 120d. The playback device 110r can comprise many or all of the components of the playback device 110a and further include the microphones 115 and voice processing components 124 (Figure 1F) . The playback device 110r optionally includes an integrated control device 130c. The control device 130c can comprise, for example, a user interface (e.g., the user interface 113 of Figure 1B) configured to receive user input (e.g., touch input, voice input) without a separate control device. In other examples, however, the playback device 110r receives commands from another control device (e.g., the control device 130a of Figure 1B) .

Referring again to Figure 1F, the microphones 115 are configured to acquire, capture, and/or receive sound from an environment (e.g., the environment 101 of Figure 1A) and/or a room in which the NMD 120a is positioned. The received sound can include, for example, vocal utterances, audio played back by the NMD 120a and/or another playback device, background voices, ambient sounds, etc. The microphones 115 convert the received sound into electrical signals to produce microphone data. The voice processing components 124 receive and analyzes the microphone data to determine whether a voice input is present in the microphone data. The voice input can comprise, for example, an activation word followed by an utterance including a user request. As those of ordinary skill in the art will appreciate, an activation word is a word or other audio cue that signifying a user voice input. For instance, in querying the

VAS, a user might speak the activation word "Alexa. " Other examples include "Ok, Google" for invoking the

VAS and "Hey, Siri" for invoking the

VAS.

After detecting the activation word, voice processing components 124 monitor the microphone data for an accompanying user request in the voice input. The user request may include, for example, a command to control a third-party device, such as a thermostat (e.g.,

thermostat) , an illumination device (e.g., a PHILIPS

lighting device) , or a media playback device (e.g., a

playback device) . For example, a user might speak the activation word “Alexa” followed by the utterance “set the thermostat to 68 degrees” to set a temperature in a home (e.g., the environment 101 of Figure 1A) . The user might speak the same activation word followed by the utterance “turn on the living room” to turn on illumination devices in a living room area of the home. The user may similarly speak an activation word followed by a request to play a particular song, an album, or a playlist of music on a playback device in the home.

d. Suitable Control Devices

Figure 1H is a partially schematic diagram of the control device 130a (Figures 1A and 1B) . As used herein, the term “control device” can be used interchangeably with “controller” or “control system. ” Among other features, the control device 130a is configured to receive user input related to the media playback system 100 and, in response, cause one or more devices in the media playback system 100 to perform an action (s) or operation (s) corresponding to the user input. In the illustrated example, the control device 130a comprises a smartphone (e.g., an iPhone ^TM, an Android phone) on which media playback system controller application software is installed. In some examples, the control device 130a comprises, for example, a tablet (e.g., an iPad ^TM) , a computer (e.g., a laptop computer, a desktop computer) , and/or another suitable device (e.g., a television, an automobile audio head unit, an IoT device) . In certain examples, the control device 130a comprises a dedicated controller for the media playback system 100. In other examples, as described above with respect to Figure 1G, the control device 130a is integrated into another device in the media playback system 100 (e.g., one more of the playback devices 110, NMDs 120, and/or other suitable devices configured to communicate over a network) .

The control device 130a includes electronics 132, a user interface 133, one or more speakers 134, and one or more microphones 135. The electronics 132 comprise one or more processors 132a (referred to hereinafter as “the processors 132a” ) , a memory 132b, software components 132c, and a network interface 132d. The processor 132a can be configured to perform functions relevant to facilitating user access, control, and configuration of the media playback system 100. The memory 132b can comprise data storage that can be loaded with one or more of the software components executable by the processor 132a to perform those functions. The software components 132c can comprise applications and/or other executable software configured to facilitate control of the media playback system 100. The memory 112b can be configured to store, for example, the software components 132c, media playback system controller application software, and/or other data associated with the media playback system 100 and the user.

The network interface 132d is configured to facilitate network communications between the control device 130a and one or more other devices in the media playback system 100, and/or one or more remote devices. In some examples, the network interface 132d is configured to operate according to one or more suitable communication industry standards (e.g., infrared, radio, wired standards including IEEE 802.3, wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G, LTE) . The network interface 132d can be configured, for example, to transmit data to and/or receive data from the playback devices 110, the NMDs 120, other ones of the control devices 130, one of the computing devices 106 of Figure 1B, devices comprising one or more other media playback systems, etc. The transmitted and/or received data can include, for example, playback device control commands, state variables, playback zone and/or zone group configurations. For instance, based on user input received at the user interface 133, the network interface 132d can transmit a playback device control command (e.g., volume control, audio playback control, audio content selection) from the control device 130 to one or more of the playback devices 110. The network interface 132d can also transmit and/or receive configuration changes such as, for example, adding/removing one or more playback devices 110 to/from a zone, adding/removing one or more zones to/from a zone group, forming a bonded or consolidated player, separating one or more playback devices from a bonded or consolidated player, among others.

The user interface 133 is configured to receive user input and can facilitate `control of the media playback system 100. The user interface 133 includes media content art 133a (e.g., album art, lyrics, videos) , a playback status indicator 133b (e.g., an elapsed and/or remaining time indicator) , media content information region 133c, a playback control region 133d, and a zone indicator 133e. The media content information region 133c can include a display of relevant information (e.g., title, artist, album, genre, release year) about media content currently playing and/or media content in a queue or playlist. The playback control region 133d can include selectable (e.g., via touch input and/or via a cursor or another suitable selector) icons to cause one or more playback devices in a selected playback zone or zone group to perform playback actions such as, for example, play or pause, fast forward, rewind, skip to next, skip to previous, enter/exit shuffle mode, enter/exit repeat mode, enter/exit cross fade mode, etc. The playback control region 133d may also include selectable icons to modify equalization settings, playback volume, and/or other suitable playback actions. In the illustrated example, the user interface 133 comprises a display presented on a touch screen interface of a smartphone (e.g., an iPhone ^TM, an Android phone) . In some examples, however, user interfaces of varying formats, styles, and interactive sequences may alternatively be implemented on one or more network devices to provide comparable control access to a media playback system.

The one or more speakers 134 (e.g., one or more transducers) can be configured to output sound to the user of the control device 130a. In some examples, the one or more speakers comprise individual transducers configured to correspondingly output low frequencies, mid-range frequencies, and/or high frequencies. In some examples, for instance, the control device 130a is configured as a playback device (e.g., one of the playback devices 110) . Similarly, in some examples the control device 130a is configured as an NMD (e.g., one of the NMDs 120) , receiving voice commands and other sounds via the one or more microphones 135.

The one or more microphones 135 can comprise, for example, one or more condenser microphones, electret condenser microphones, dynamic microphones, and/or other suitable types of microphones or transducers. In some examples, two or more of the microphones 135 are arranged to capture location information of an audio source (e.g., voice, audible sound) and/or configured to facilitate filtering of background noise. Moreover, in certain examples, the control device 130a is configured to operate as playback device and an NMD. In other examples, however, the control device 130a omits the one or more speakers 134 and/or the one or more microphones 135. For instance, the control device 130a may comprise a device (e.g., a thermostat, an IoT device, a network device) comprising a portion of the electronics 132 and the user interface 133 (e.g., a touch screen) without any speakers or microphones.

III. Example Systems and Devices

Figure 2A is a front isometric view of a playback device 210 configured in accordance with examples of the disclosed technology. Figure 2B is a front isometric view of the playback device 210 without a grille 216e. Figure 2C is an exploded view of the playback device 210. Referring to Figures 2A-2C together, the playback device 210 comprises a housing 216 that includes an upper portion 216a, a right or first side portion 216b, a lower portion 216c, a left or second side portion 216d, the grille 216e, and a rear portion 216f. A plurality of fasteners 216g (e.g., one or more screws, rivets, clips) attaches a frame 216h to the housing 216. A cavity 216j (Figure 2C) in the housing 216 is configured to receive the frame 216h and electronics 212. The frame 216h is configured to carry a plurality of transducers 214 (identified individually in Figure 2B as transducers 214a-f) . The electronics 212 (e.g., the electronics 112 of Figure 1C) is configured to receive audio content from an audio source and send electrical signals corresponding to the audio content to the transducers 214 for playback.

The transducers 214 are configured to receive the electrical signals from the electronics 112, and further configured to convert the received electrical signals into audible sound during playback. For instance, the transducers 214a-c (e.g., tweeters) can be configured to output high frequency sound (e.g., sound waves having a frequency greater than about 2 kHz) . The transducers 214d-f (e.g., mid-woofers, woofers, midrange speakers) can be configured output sound at frequencies lower than the transducers 214a-c (e.g., sound waves having a frequency lower than about 2 kHz) . In some examples, the playback device 210 includes a number of transducers different than those illustrated in Figures 2A-2C. For example, the playback device 210 can include fewer than six transducers (e.g., one, two, three) . In other examples, however, the playback device 210 includes more than six transducers (e.g., nine, ten) . Moreover, in some examples, all or a portion of the transducers 214 are configured to operate as a phased array to desirably adjust (e.g., narrow or widen) a radiation pattern of the transducers 214, thereby altering a user’s perception of the sound emitted from the playback device 210.

In the illustrated example of Figures 2A–2C, a filter 216i is axially aligned with the transducer 214b. The filter 216i can be configured to desirably attenuate a predetermined range of frequencies that the transducer 214b outputs to improve sound quality and a perceived sound stage output collectively by the transducers 214. In some examples, however, the playback device 210 omits the filter 216i. In other examples, the playback device 210 includes one or more additional filters aligned with the transducers 214b and/or at least another of the transducers 214.

IV. Example Systems and Methods for Stabilizing Playback Devices

As noted previously, stiffness within an audio transducer can reduce efficiency of the audio transducer as well as decrease acoustic performance. An audio transducer having a suspension element with a negative stiffness can reduce the total stiffness of the audio transducer, and, as a result, provide distinct advantages. However, these suspension elements can be subjected to high levels of stress during operation, which can cause these suspension elements to fail even under normal operating conditions. Examples of the present disclosure provide negative stiffness suspension elements that include one or more stress distributing features. These stress distributing features allow for the suspension element with a negative stiffness to withstand the operating stress. Examples of such suspension elements are described below with respect to Figures 3A–4.

Figures 3A and 3B are a block diagram and a perspective view, respectively, of a playback device 310 including a transducer 314. Figure 3C is a schematic cross-sectional view of the transducer 314, and Figure 3D is a perspective view of the transducer 314 with several components hidden for clarity. Referring to Figures 3A–3D together, the playback device 310 includes an enclosure 316 that is coupled to and carries the audio transducer 314. The enclosure 316 can define an internal chamber (not shown) and the audio transducer 314 can couple with the enclosure 316 so that at least a part of the audio transducer 314 is partially disposed within the internal chamber. In some examples, the enclosure 316 is sealed when the audio transducer 314 couples with the enclosure 316 so that air cannot move into or out of the internal chamber. The playback device 310 can further include electronics 312. The electronics 312 can be disposed within the internal chamber.

In some examples, the audio transducer 314 includes a frame 316h, which defines the body of the audio transducer 314 and extends around the sides and base of the audio transducer 314. In some examples, when the frame 316h attaches the audio transducer 314 to the enclosure 316, sealing the enclosure 316 and fluidly coupling the audio transducer 314 with the internal chamber. A magnet 326 (Figure 3C) attached to a lower portion of the frame 316h defines an aperture within which a voice coil 328 is at least partially disposed.

The audio transducer 314 can further include a diaphragm 320 having a radially outer portion coupled to an upper portion of the frame 316h, and a radially inner portion coupled to the voice coil 328. In some examples, a surround 322 resiliently attaches the radially outer portion of the diaphragm 320 to the frame 316h. The audio transducer 314 can also include a dust cap 324, which couples to an upper portion of the voice coil 328. In various examples, the diaphragm 320 can comprise a thin sheet of paper, plastic, metal, or other suitable material formed in a generally conical or frustum shape. The surround 322 can comprise a flexible material such as a foam, rubber, or other suitable material that permits the diaphragm 320 to move inward and outward along the axis L1.

In some examples, the audio transducer 314 can include

suspension elements

350a, 350b, 350c, and 350d (collectively referred to as the “suspension elements 350” ) . These suspension elements 350 can be configured to contribute a negative stiffness to the transducer along the axis L1. This contribution of negative stiffness lowers the overall stiffness of the transducer 314, thereby improving the transducer’s 314 efficiency. Although particular implementations of such negative-stiffness suspension elements 350 are shown and described herein, in various examples other types of negative-stiffness suspension elements can be used in addition to or instead of the particular suspension elements 350. For example, the transducer 314 can include one or more buckled columns, compressed springs, or other negative stiffness mechanisms.

The suspension elements 350 can each have an inner end coupled to the voice coil 328 and an outer end coupled to the frame 316h. In various examples, the suspension elements 350 can include a radially inner portion coupled to the voice coil 328 and a radially outer portion coupled to the frame 316h. These suspension elements 350 can each be arranged in compression such that they exert a radially inward force against the voice coil 328 while secured to the frame 316h. At a rest position, the radially inward force may cause no movement of the voice coil 328. However, as the voice coil 328 moves outward (e.g., along axis L1 in Figure 3C) , radially inner end of the suspension element 350 moves with the voice coil 328 while the radially outer portion of the suspension element 350 remains coupled to the frame 316h and stationary. In this arrangement, the suspension element’s 350 force exerted on the voice coil 328 includes both a radially inward component and an axial component (e.g., along axis L1) , such that the suspension element 350 urges the voice coil 328 further outward along the axis L1. In a similar fashion, when the voice coil 328 moves inwardly (i.e., along axis L1) , the suspension element 350 exerts a force (due to the suspension element 350 being in compression) that urges the voice coil 328 further inwardly.

In several examples, the suspensions elements 350 can be evenly distributed within the audio transducer 314 such that the suspensions elements 350 remain substantially equidistant from one another (e.g., the suspension elements 350 can be substantially evenly spaced apart circumferentially around the voice coil 328) . Additionally, or alternatively, a first suspension element 350 can be positioned within the audio transducer 314 so that a second suspension element 350 is positioned on an opposing side of the voice coil 328. In such configurations, the radially inward force exerted by each suspension element 350 can be substantially canceled out by the radially inward force exerted by the other suspension elements 350. As such, there may be no net radial force exerted on the voice coil 328 by the combination of suspension elements 350. In one example, as illustrated in Figure 3D, the suspension element 350b is positioned on a first side of the voice coil 328 while the suspension element 350d is positioned on a second side of the voice coil 328 that opposes the first side. As will be described in more detail elsewhere herein, the suspension elements 350 can impart a negative stiffness value to the transducer (as measured along the axis L1) and can also include one or more stress distributing features.

The playback device 310 can include one or more stabilizers 330 (Figure 3A) . The stabilizer (s) 330 can include one or more components that facilitate the appropriate position, movement, and operation of various components of the transducer 314, such as a diaphragm 320. The stabilizer 330 can couple to the enclosure 316 and be at least partially disposed within the internal chamber. In some examples, the stabilizer 330 can be disposed external to the internal chamber. The stabilizer 330 can be communicatively coupled to the electronics 312 so that the stabilizer 330 can receive commands or other signals from the electronics 312. In some examples, the stabilizer 330 can include a pump and/or a pneumatic valve. Additionally, or alternatively, the stabilizer can include one or more sensors and one or more control members.

In various examples, the playback device 310 can include other components 310j in addition to components described herein. For instance, the playback device 310 can include a user interface, an input/output, and/or any other desired component. In some examples, the enclosure 316 can take the form of a housing. Additionally, or alternatively, the internal chamber can take the form of a cavity. In various examples, the audio transducer 314 can include other components 314j. For instance, the audio transducer can include one or more tinsel leads coupled with the voice coil 328 and the frame 316h.

In operation, the playback device 310 is configured to receive audio signals or data from one or more media sources and play back the received audio signals or data as sound. In some examples, the playback device 310 plays back the audio signals or data as sound via the audio transducer 314. For instance, the voice coil 328 of the audio transducer 314 can receive one or more electrical signals from an amplifier, causing a resultant magnetic field that moves the voice coil 328 axially towards or away from the magnet 326 (e.g., the voice coil 328 can move in a first direction and/or second direction along the axis L1 shown in Figure 3C) . The axial movement of the voice coil 328 also causes corresponding axial movement of the diaphragm 320. As the diaphragm 320 moves axially, the diaphragm 320 pushes and pulls on the surrounding air, generating sound waves at one or more frequencies.

In addition to playing back received audio signals or data as sound, the playback device 310 can also self-stabilize during operation. For example, the stabilizer 330 can stabilize the playback device 310 to ensure the playback device 310 can remain operational. In some examples, the stabilizer 330 can pump air into or out of the enclosure 316 to change the air pressure, which can stabilize the playback device 310. In various examples, the stabilizer 330 can send a signal to drive the voice coil 328 to a stable position. By self-stabilizing, the playback device 310 can counteract any instability issues that arise from utilizing a suspension element with a negative stiffness, such as the suspension element 350.

As previously noted, the audio transducer 314 can include one or more suspension elements 350. Figure 3E illustrates a perspective view of a suspension element 350 in accordance with the examples of the disclosed technology and Figure 3F illustrates a top view of the suspension element 350 from Figure 3E. As noted previously, these suspension elements 350 can contribute a negative stiffness to the transducer 314 along the axis L1, thereby increasing the efficiency of the transducer 314. Referring to Figures 3A–3F together, the suspension element 350 can include a body 351 having a first end portion 356 and a second end portion 358 opposite the first end portion 356. In some examples, the first end portion 356 can take the form of a radially outer portion and the second end portion 358 can take the form of a radially inner portion. The first end portion 356 can include a first aperture 357 configured to mate with a fastener or other coupling mechanism to the transducer, and the second end portion 358 can include a second aperture 359 configured to mate with a fastener or other coupling mechanism to the transducer. Although the illustrated example utilizes

apertures

357, 359 to couple the suspension element 350 to the transducer, in various implementations other coupling mechanisms can be employed.

The body 351 can be formed from a first member 352 and a second member 354. The first and

second member

352, 354 can be overlaid on top of one another and joined together at the first and

second end portions

356, 358. The first and

second members

352, 354 can separate from each other between the first and

second end portion

356, 358 such that a gap 361 forms between the first and

second members

352, 354 and so that a least a portion of the first and

second member

352, 354 are spaced apart from each other. As the first and

second end portions

356, 358 are brought closer together, the gap 361 can increase (e.g., intermediate portions of the first and

second members

360a and 360b can move apart from one another) , and conversely as the first and

second end portions

356, 358 are pulled further apart, the gap 361 may decrease (e.g., the intermediate portions of the first and

second members

360a and 360b can move closer toward one another) .

The first member 352 can include a first corrugated portion 360a and the second member 354 can include a second corrugated portion 360b (the

corrugated portions

360a, 360b being collectively referred to as the “corrugated portions 360” ) . The corrugated portions 360 can form a wave-like structure in which the first and/or

second member

352, 354 form a series of grooves and ridges. In some examples, the corrugated portions 360

form

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more ridges and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more grooves. In several examples, the corrugated portions 360 can take the form of an undulating portion, for example having a generally serpentine or sinusoidal cross-sectional shape. In various examples, the corrugated portions 360 are positioned between the first and

second end portions

356, 358.

The suspension elements 350 can have a varied width across the length of the body 351. For example, the suspension elements 350 can include one or more narrowed portions formed along the length of the body 351. As illustrated in Figure 3F, the suspension element 350 defines a first narrowed portion 362 and a second narrowed portion 366 along the length of the body 351. The first and second narrowed

portions

362, 366 can include a first width W1 that is narrower than other portions of the body 351 having a second width W2. For instance, the first and second narrowed

portions

362, 366 can each have a width that is less than the width of the first and

second end portions

356, 358. In some examples, the width of one or both of the narrowed

portions

362, 366 is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%less than the maximum width of the first or

second member

352, 354. In various examples, the width of one or both of the narrowed

portions

362, 366 have a continuous slope across the length of the narrowed portion 362. In several examples, the first and second narrowed

portions

362, 366 can be spaced apart from each other such that a wider (or narrower) portion is positioned between the first and second narrowed

portions

362, 366. For instance, as illustrated in Figure 3F, an intermediate portion 364 can be positioned between the first and second narrowed

portions

362, 366, with the intermediate portion 364 having a third width W3 different than (e.g., wider or narrower than) either or both of the first and second narrowed

portions

362, 366. In certain examples, other portions of the suspension elements 350 optionally have different widths than W1, W2, and/or W3. For instance, as shown in FIG. 3F, an intervening portion 363 between the narrowed portion 362 and the intermediate portion 364 has a fourth width W4 different than (e.g., wider or narrower than) any of the widths W1, W2, and/or W3. In other examples, however, the suspension elements 350 have a generally consistent width such that the widths W1, W2, W3 and W4 are approximately the same.

In various examples, first and second narrowed

portions

362, 366 and the intermediate portion 364 can be formed along the corrugated portions 360 of the first and

second members

352, 354. In several examples, the largest width of the suspension elements 350 can be at the intermediate portion 364. Additionally, or alternatively, the intermediate portion 364 can have a width that is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%larger than the smallest width at the first and second narrowed

portions

362, 366.

As previously noted, the suspension elements 350 can couple to the frame 316h and the voice coil 328. As best seen in Figures 3C and 3D, in some examples, the suspension elements 350 can be fixed to the frame via a fastener 344. In various examples, the suspension elements 350 couple to the voice coil 328 via a collar member 340. The collar member 340 can couple to the voice coil 328 so that the collar member 340 is disposed around an outer surface of the voice coil 328. In several examples, the collar member 340 can be fixed to voice coil 328 with an adhesive. The collar member 340 can include one or more coupling portions 342. The suspension elements 350 can couple to the collar member 340 at the coupling portions 342. In some examples, when the suspension elements 350 are at rest (e.g., the voice coil 328 is not moving) the suspension elements 350 can extend in a direction that intersects the voice coil’s 328 direction of travel. For instance, the suspension elements 350 can extend along the axis L2 while the transducer is at rest, which intersect the voice coil’s 328 direction of travel along the axis L1.

When coupled to the voice coil 328, the collar member 340 can be configured to move with the voice coil 328 during operation. For example, when the voice coil 328 moves in a first direction, the collar member 340 can also move in the first direction with the voice coil 328. When coupled to the collar member 340, the suspension elements 350 can also be configured to move with the voice coil 328 during operation. For example, when the voice coil 328 moves along the axis L1 (e.g., in a first or second direction along the axis L1) , the suspension element 350 can also move along the axis L1 with the voice coil 328. In some examples, only a portion of the suspension element 350 moves with the voice coil 328 during operation. For instance, the first end portion 356 of the suspension element 350 can be fixed to the frame 316h and remain stationary relative to the other portions of the suspension element 350 while the first member 352, the second member 354, and the second end portion 358 can move in response to any movement from the voice coil 328.

The suspension elements 350 can keep some of the components within the audio transducer 314 properly positioned during operation. For instance, the suspension element 350 can keep the voice coil 328 properly aligned with the magnet 326. The suspension elements 350 can have a stiffness, which represents the ability of the suspension elements 350 to resist displacement from an applied force. This stiffness can be a positive value, meaning the suspension elements 350 resist the applied force by responding with a counteracting force in the opposite direction of the applied force. In some examples, the stiffness can have a negative value (e.g., a negative stiffness) . When the suspension elements 350 have a negative stiffness, the suspension elements 350 respond to an applied force with an additional displacement in the same direction of the applied force.

In some examples, the suspension elements 350 are arranged within the transducer such that the bodies 351 of the suspension elements 350 are in compression. For instance, the body 351 can be compressed along the axis L2, and/or perpendicular to the axis L1 when the transducer 314 is at rest. By compressing the suspension elements 350 in this manner, the suspension elements 350 will have a negative stiffness along the axis L1. As a result of this configuration, the suspension elements 350 respond to a displacement resulting from an applied force along the axis L1 with an additional force in the same direction as the applied force (e.g., the suspension element is biased to move in the same direction as the applied force) . For example, when a force is applied to the suspension element 350 along the axis L1, the compressed suspension element 350 causes the suspension element 350 to move in the same direction as the applied force.

Because the suspension elements 350 are biased to move along the axis L1 once displaced from a stable rest position, the suspension elements 350 can reduce the amount of power that is required to operate the audio transducer 314. When the voice coil 328 moves in a particular direction along the axis L1, the suspension elements 350 will bias the voice coil 328 in its direction of travel, which counteracts the stiffness caused from the surrounding air and other components within the audio transducer 314. Accordingly, the audio transducer 314 can be more efficient when utilizing one or more suspension elements 350.

In some examples, the total stiffness of the playback device 310 (e.g., the stiffness of all the components of the playback device 310 and the stiffness of the air within the internal chamber of the enclosure 316) can be tuned to a desired value. By tuning the total stiffness of the playback device 310, the resonant frequency of the playback device 310 can also be adjusted accordingly. For example, lowering the total stiffness of the playback device 310 would lower the resonant frequency of the playback device 310. In contrast, increasing the total stiffness of the playback device 310 would increase the resonant frequency of the playback device 310. Thus, by being able to tune the total stiffness, a user can produce a playback device 310 with a desired (or favorable) resonant frequency. In some examples, the amount of negative stiffness included with the system can be adjusted by including or removing additional suspension elements 350. For example, a playback device 310 with ten suspension elements 350 will have a lower total stiffness than a playback device 310 with four suspension elements 350. In some examples, the playback device 310 can include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more suspension elements 350. In various examples, the total stiffness can be positive or negative, depending on the desired operating characteristics.

As previously noted, compressing the suspension elements 350 can cause high levels of stress within each suspension element 350. This stress is compounded by the movement the suspension element 350 undergoes during operation (e.g., the movement with the voice coil 328 during operation) . In some examples, the stress can be so extreme that conventional suspension elements would fail under normal operating conditions. To overcome the high levels of stress, the suspension elements 350 can include one or more features that distribute the stress across the suspension element 350.

In some examples, the corrugated portions 360 can distribute the stress across the suspension element 350. By including the corrugated portions 360, stress within the suspension element 350 does not concentrate at one particular area but can be more evenly distributed across the length of the corrugated portions 360. In several examples, the narrowed

portions

362, 366 can reduce the amount of stress at a particular area along the length of the suspension element 350. By including the narrowed

portions

362, 366, the concentration of stress at the narrowed

portions

362, 366, at the center of the suspension element 350, and at the first and

second end portions

356, 358 is greatly reduced. Additionally, or alternatively, including a wider intermediate portion 364 can reduce the amount of stress at a particular area along the length of the suspension element 350. For example, including an intermediate portion 364 that is wider than the surrounding portions of the suspension element 350 can reduce the concentration of stress at any particular point on the intermediate portion 364.

In addition to the features for distributing stress, the suspension elements 350 can be sized and configured in a manner that reduces the levels of stress across the suspension elements 350. In some examples, the first and

second members

352, 354 of the suspension elements 350 can each have a thickness between 0.2 mm to 0.05 mm. In various examples, the first and

second members

352, 354 can each have a thickness of 0.1 mm. In some examples, the first and

second members

352, 354 can each have an average width between 15 mm to 1 mm. In various examples, the first and

second members

352, 354 can each have an average width of 9.5 mm. Having a thickness and width within these ranges allows for the suspension element 350 to retain enough flexibility for operation while also retaining enough rigidity to manage the stress of operation. In some examples, the suspension element 350 can be made from a metal, such as steel or spring steel. Being made from steel allows the suspension element 350 to withstand the high stress whereas other materials would fail under a similar stress.

Figure 4 illustrates an example method 400 of assembling a playback device in accordance with examples of the disclosed technology. The method 400 can be performed with any example playback device described herein, such as the playback device 310. The method starts at step 401 with coupling the suspension element (e.g., a suspension element 350 shown in Figure 3C) to a collar member (e.g., the collar member 340 shown in Figure 3C) . The suspension element can be coupled to the collar member by coupling the suspension element to a coupling portion (e.g., the coupling portion 342 shown in Figure 3C) . In some examples, the suspension element can couple to the collar member via a fastener (e.g., rivet, screw, etc. ) or can be fixed to the collar member in another manner (e.g., through welding, an adhesive, etc. ) . In some examples, a fixture can be used to position the various suspension elements in their proper orientations with respect to the collar member before securing the suspension elements to the collar member. For example, such a fixture can include a central portion configured to receive the collar member thereon, and a plurality of receptacles or other guiding portions configured to receive the suspension elements therein. Once the suspension elements are placed in their respective receptacles, the first end portions of the suspension elements can be secured to the collar member, for example using fasteners or other suitable technique.

After coupling the suspension element to the collar member, the method 400 continues with step 402. At step 402, the collar member is coupled to the voice coil (e.g., the voice coil 328) . In some examples, the collar member is fixed to the voice coil with an adhesive. In examples utilizing a fixture as noted above, such a fixture can be slidably passed over the voice coil such that the collar member surrounds the voice coil and the suspension elements extend radially outwardly from the collar member. Once in this position, the collar member can be secured to the voice coil using adhesive or other technique, after which the collar member and suspension elements can be released from the fixture, which can then be removed entirely.

Next, the method 400 continues with step 403. At step 403, the suspension elements are compressed. In some examples, each suspension element is compressed along the length of the suspension element and perpendicular to the voice coil’s direction of travel (e.g., along the axis L2 while at the rest position) . By compressing the suspension element in this manner, the suspension element can have a negative stiffness along the voice coil’s direction of travel (e.g., the suspension element is biased to move along the axis L1) . Next, the method 400 proceeds to step 404, in which the suspension element is coupled to the frame (e.g., the frame 316h) . The suspension element can be coupled to the frame so that the suspension element remains compressed when coupled to both the frame and the collar member. In some examples, the suspension element couples to the frame through a fastener (e.g., the fastener 344, which can take the form of a rivet, screw, etc. ) .

V. Conclusion

The above discussions relating to transducers, playback devices, controller devices, playback zone configurations, and media content sources provide only some examples of operating environments within which functions and methods described below may be implemented. Other operating environments and/or configurations of transducers, media playback systems, playback devices, and network devices not explicitly described herein may also be applicable and suitable for implementation of the functions and methods.

The description above discloses, among other things, various example systems, methods, apparatus, and articles of manufacture including, among other components, firmware and/or software executed on hardware. It is understood that such examples are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of the firmware, hardware, and/or software examples or components can be embodied exclusively in hardware, exclusively in software, exclusively in firmware, or in any combination of hardware, software, and/or firmware. Accordingly, the examples provided are not the only ways) to implement such systems, methods, apparatus, and/or articles of manufacture.

Additionally, references herein to “example” means that a particular feature, structure, or characteristic described in connection with the example can be included in at least one example of an invention. The appearances of this phrase in various places in the specification are not necessarily all referring to the same example, nor are separate or alternative examples mutually exclusive of other examples. As such, the examples described herein, explicitly and implicitly understood by one skilled in the art, can be combined with other examples.

The specification is presented largely in terms of illustrative environments, systems, procedures, steps, logic blocks, processing, and other symbolic representations that directly or indirectly resemble the operations of data processing devices coupled to networks. These process descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. Numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, it is understood to those skilled in the art that certain examples of the present disclosure can be practiced without certain, specific details. In other instances, well known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring examples of the examples. Accordingly, the scope of the present disclosure is defined by the appended claims rather than the foregoing description of examples.

When any of the appended claims are read to cover a purely software and/or firmware implementation, at least one of the elements in at least one example is hereby expressly defined to include a tangible, non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on, storing the software and/or firmware.

The disclosed technology is illustrated, for example, according to various examples described below. Various examples of examples of the disclosed technology are described as numbered examples (1, 2, 3, etc. ) for convenience. These are provided as examples and do not limit the disclosed technology. It is noted that any of the dependent examples may be combined in any combination, and placed into a respective independent example. The other examples can be presented in a similar manner.

Example 1. An audio transducer, comprising: a frame; a magnet coupled to the frame; a voice coil axially aligned with the magnet, wherein the voice coil is configured to receive an electrical signal from an amplifier, and, in response to the received electrical signal, correspondingly move a diaphragm in a first direction or a second direction along an axis; and a suspension element coupled to the frame and to the voice coil, wherein the suspension element comprises: a first member having a first end portion coupled to the frame and a second end portion coupled to the voice coil and opposite the first end portion, wherein the first member includes a corrugated portion between the first and second end portions; and a second member having a first end portion coupled to the first end portion of the first member and a second end portion coupled to the second end portion of the first member, wherein the second member includes a corrugated portion between the first and second end portions of the second member, wherein the suspension element comprises a negative stiffness along the axis.

Example 2. The audio transducer of Example 1, wherein the width of the first member varies across the length of the first member.

Example 3. The audio transducer of Example 1 or 2, wherein the first member comprises a thickness, and wherein the thickness is between 0.2 mm and 0.05 mm.

Example 4. The audio transducer of any one of the proceeding Examples, further comprising a collar member coupled to the voice coil, and wherein the suspension element couples to the collar member.

Example 5. The audio transducer of any one of the proceeding Examples, wherein the corrugated portion of the first member is spaced apart from the corrugated portion of the second member.

Example 6. The audio transducer of any one of the proceeding Examples, wherein the suspension element is a first suspension element, the audio transducer further comprising a second suspension element coupled to the voice coil on an opposing side to the first suspension element.

Example 7. The audio transducer of any one of the proceeding Examples, wherein, when at rest, the suspension element extends along a direction substantially perpendicular to the axis.

Example 8. An audio transducer, comprising: a frame; a voice coil coupled to the frame, wherein the voice coil is configured to receive an electrical signal from an amplifier, and, in response to the received electrical signal, correspondingly move a diaphragm along an axis; and a suspension element having a radially outer portion coupled to the frame and a radially inner portion coupled to the voice coil, wherein the suspension element comprises: a first member and a second member each having an inner end portion, an outer end portion opposite the inner end portion, and an intermediate portion comprising a plurality of grooves and ridges, wherein the first member and the second member are coupled together such that the inner end portions are joined together, the outer end portions are joined together, and the intermediate portions are separated from one another by a gap.

Example 9. The audio transducer of Example 8, wherein the suspension element has a negative stiffness along the axis.

Example 10. The audio transducer of Example 8 or 9, wherein the intermediate portions of the first and second members each comprise a width, and wherein the width varies along the length of the intermediate portions.

Example 11. The audio transducer of any one of the Examples 8–10, further comprising a collar member coupled to the voice coil, wherein the radially inner portion of the suspension element couples to the collar member.

Example 12. The audio transducer of any one of the Examples 8–11, wherein the suspension element is a first suspension element, the audio transducer further comprising a second suspension element having radially outer portion coupled to the frame and a radially inner portion coupled to the voice coil.

Example 13. The audio transducer of any one of the Examples 8–12, wherein the intermediate portions of the first and second members each comprise a thickness, and wherein the thickness is between 0.2 mm and 0.05 mm.

Example 14. The audio transducer of any one of the Examples 8–13, wherein the axis is a first axis, and wherein the suspension element is compressed along a second axis that intersects the first axis.

Example 15. An audio transducer, comprising: a frame; a voice coil coupled to the frame, wherein the voice coil is configured to receive an electrical signal from an amplifier, and, in response to the received electrical signal, correspondingly move a diaphragm in a first direction; and a suspension member having a first end portion coupled to the frame and a second end portion coupled to the voice coil, wherein the suspension member comprises an undulating portion between the first and second end portions, wherein the suspension member is configured to be compressed in a second direction such that the suspension member comprises a negative stiffness along the first direction when coupled to the frame and the voice coil.

Example 16. The audio transducer of Example 15, wherein the undulating portion comprises a first narrowed portion and a second narrowed portion, wherein the width of the first and second narrowed portions is less than the width of the first and second end portions.

Example 17. The audio transducer of Example 15 or 16, further comprising a collar member coupled to the voice coil, wherein the second end portion of the suspension member couples to the collar member.

Example 18. The audio transducer of any one of the Examples 15–17, wherein the undulating portion comprises a thickness, and wherein the thickness is between 0.2 mm and 0.05 mm.

Example 19. The audio transducer of any one of the Examples 15–18, wherein the suspension member is a first suspension member, the audio transducer further comprising a second suspension member having a first end portion coupled to the frame and a second end portion coupled to the voice coil.

Example 20. The audio transducer of any one of the Examples 15–19, wherein the second direction is substantially perpendicular to the first direction.

Claims

An audio transducer, comprising:

a frame;

a magnet coupled to the frame;

a voice coil axially aligned with the magnet, wherein the voice coil is configured to receive an electrical signal from an amplifier, and, in response to the received electrical signal, correspondingly move a diaphragm in a first direction or a second direction along an axis; and

a suspension element coupled to the frame and to the voice coil, wherein the suspension element comprises:

a first member having a first end portion coupled to the frame and a second end portion coupled to the voice coil and opposite the first end portion, wherein the first member includes a corrugated portion between the first and second end portions; and

a second member having a first end portion coupled to the first end portion of the first member and a second end portion coupled to the second end portion of the first member, wherein the second member includes a corrugated portion between the first and second end portions of the second member,

wherein the suspension element comprises a negative stiffness along the axis.
The audio transducer of Claim 1, wherein the width of the first member varies across the length of the first member.
The audio transducer of Claim 1, wherein the first member comprises a thickness, and wherein the thickness is between 0.2 mm and 0.05 mm.
The audio transducer of Claim 1, further comprising a collar member coupled to the voice coil, and wherein the suspension element couples to the collar member.
The audio transducer of Claim 1, wherein the corrugated portion of the first member is spaced apart from the corrugated portion of the second member.
The audio transducer of Claim 1, wherein the suspension element is a first suspension element, the audio transducer further comprising a second suspension element coupled to the voice coil on an opposing side to the first suspension element.
The audio transducer of Claim 1, wherein, when at rest, the suspension element extends along a direction substantially perpendicular to the axis.
An audio transducer, comprising:

a frame;

a voice coil coupled to the frame, wherein the voice coil is configured to receive an electrical signal from an amplifier, and, in response to the received electrical signal, correspondingly move a diaphragm along an axis; and

a suspension element having a radially outer portion coupled to the frame and a radially inner portion coupled to the voice coil, wherein the suspension element comprises:

a first member and a second member each having an inner end portion, an outer end portion opposite the inner end portion, and an intermediate portion comprising a plurality of grooves and ridges,

wherein the first member and the second member are coupled together such that the inner end portions are joined together, the outer end portions are joined together, and the intermediate portions are separated from one another by a gap.
The audio transducer of Claim 8, wherein the suspension element has a negative stiffness along the axis.
The audio transducer of Claim 8, wherein the intermediate portions of the first and second members each comprise a width, and wherein the width varies along the length of the intermediate portions.
The audio transducer of Claim 8, further comprising a collar member coupled to the voice coil, wherein the radially inner portion of the suspension element couples to the collar member.
The audio transducer of Claim 8, wherein the suspension element is a first suspension element, the audio transducer further comprising a second suspension element having radially outer portion coupled to the frame and a radially inner portion coupled to the voice coil.
The audio transducer of Claim 8, wherein the intermediate portions of the first and second members each comprise a thickness, and wherein the thickness is between 0.2 mm and 0.05 mm.
The audio transducer of Claim 8, wherein the axis is a first axis, and wherein the suspension element is compressed along a second axis that intersects the first axis.
An audio transducer, comprising:

a frame;

a voice coil coupled to the frame, wherein the voice coil is configured to receive an electrical signal from an amplifier, and, in response to the received electrical signal, correspondingly move a diaphragm in a first direction; and

a suspension member having a first end portion coupled to the frame and a second end portion coupled to the voice coil, wherein the suspension member comprises an undulating portion between the first and second end portions, wherein the suspension member is configured to be compressed in a second direction such that the suspension member comprises a negative stiffness along the first direction when coupled to the frame and the voice coil.
The audio transducer of Claim 15, wherein the undulating portion comprises a first narrowed portion and a second narrowed portion, wherein the width of the first and second narrowed portions is less than the width of the first and second end portions.
The audio transducer of Claim 15, further comprising a collar member coupled to the voice coil, wherein the second end portion of the suspension member couples to the collar member.
The audio transducer of Claim 15, wherein the undulating portion comprises a thickness, and wherein the thickness is between 0.2 mm and 0.05 mm.
The audio transducer of Claim 15, wherein the suspension member is a first suspension member, the audio transducer further comprising a second suspension member having a first end portion coupled to the frame and a second end portion coupled to the voice coil.
The audio transducer of Claim 15, wherein the second direction is substantially perpendicular to the first direction.