IL272380B2

IL272380B2 - Configurable microphone assembly

Info

Publication number: IL272380B2
Application number: IL272380A
Authority: IL
Inventors: Kramer Yuval
Original assignee: Kramer Electronics Ltd; Kramer Yuval
Priority date: 2020-01-30
Filing date: 2020-01-30
Publication date: 2023-08-01
Also published as: IL272380A; IL272380B1

Description

Configurable Microphone Assembly FIELD OF THE INVENTION This invention relates to microphones having adjustable configuration.

BACKGROUND OF THE INVENTION Most microphones are configured for use under specific conditions and have polar pickup patterns that are optimized for the intended use. As is known, microphones may be of the following types: Omnidirectional:Omnidirectional microphones are microphones that pick up sound with equal gain from all sides or directions of the microphone. This means that whether a user speaks into the microphone from the front, back, left or right side, the microphone will record the signals all with equal gain. This is in contrast to unidirectional microphones, which pick up sound with high sensitivity only from a specific side.An omnidirectional microphone's response is generally considered to be a perfect sphere in three dimensions. Cardioid:The most common unidirectional microphone is a cardioid microphone, so named because the sensitivity pattern is "heart-shaped". Cardioid microphones are used in applications where sound needs to be picked up from the front and sides but not the rear. An example of this may be musical performance where a singer may be singing in the front, a band playing instruments on the sides, with an audience of viewers in the back. In a scenario, it may be desired only to record the music, the singer in front and band on the sides, but not the audience in the rear. For this type of scenario, cardioid microphones have great use and application.

Sub-cardioid:The sub-cardioid (also known as wide cardioid) microphone has no null points. It is produced with about 7:3 ratio with 3-10 dB level between the front and back pickup. The sub-cardioid microphone has a polar pattern that resembles the midway point between an omnidirectional and cardioid pattern. It is unidirectional (most sensitive to on-axis sounds) but will also pick up sounds from every other direction with clarity (though with less amplitude). Boundary microphone:Several approaches have been developed for effectively using a microphone in less-than-ideal acoustic spaces, which often suffer from excessive reflections from one or more of the surfaces (boundaries) that make up the space. If the microphone is placed in, or very close to, one of these boundaries, the reflections from that surface have the same timing as the direct sound, thus giving the microphone a hemispherical polar pattern and improved intelligibility.US 2019/0379960 discloses an array of three boundary microphones mounted to a common shock-mounted hub, in which each of the three microphones is angularly adjustable. The microphones are used in conference rooms and are adjusted to be directed to different speakers. Thus, Fig. 9 of this publication shows use of the microphone around a conference table seating none participants. Each microphone assembly is pivotally mounted to a suspension ring so that each is pivotal through an arc of about 70°. This adjustment arc is shown in phantom lines in the figure and allows the microphones to be positioned at any selected angular position such that they point directly at the intended participant to best pick up audio voice signals from that participant.There appears to be no suggestion to direct two microphones simultaneously to the same participant or to configure the microphones in a manner that affects the directional performance of the microphones.

SUMMARY OF THE INVENTION It is an objection of the invention to provide a microphone assembly whose pickup polar pattern can be adjusted to approximate any of the standard configurations described in the Background, i.e. Omnidirectional , Cardioid , Sub-cardioidand Boundary .

This object is realized in accordance with the invention by a configurable boundary microphone assembly, comprising first and second omni-directional microphones each mounted on a respective first and second support structure in a co-planar arrangement, the first and second support structures being mutually rotatable about a pivot axis normal to a plane of said support structures; whereby rotation of the support structures changes the arrangement of the first and second microphones thereby altering a combined pickup polar pattern of the microphone assembly.In an embodiment of the invention the microphone assembly includes a dualcondenser boundary microphone with selectable polar pattern.

BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: FIG. 1shows schematically a plan view of a microphone assembly according to an embodiment of the invention; FIG. 2shows a side view of the microphone assembly; FIG. 3shows a perspective view of the microphone assembly; FIGS. 4, 6and 8show schematically configurations of the microphone assembly each having different respective combined pickup polar patterns; FIGS. 5, 7and 9show typical respective pickup polar patterns for the microphone assemblies shown in FIGS. 4, 6 and 8; and FIGS. 10 to 12show pictorially different uses of the microphone assembly according to the invention.

Claims

- 8 - CLAIMS:

1. A configurable microphone assembly, comprising: first and second omni-directional microphones each mounted on a respective first and second support structure in a co-planar arrangement, the first and second support structures being mutually rotatable about a pivot axis normal to a plane of said support structures, and a user-selectable control circuit that allows respective output signals of the first and second microphones to be summed to form a single composite output signal; whereby rotation of the support structures changes the arrangement of the first and second microphones relative to a longitudinal axis of the assembly thereby altering a combined pickup polar pattern of the microphone assembly.

2. The microphone assembly according to claim 1, wherein the first and second microphones are based on MEMS (Micro-Electro-Mechanical Systems) technology.

3. The microphone assembly according to claim 2, wherein the first and second microphones are mounted on respective printed circuit boards (PCB) that are mounted upright on the respective support structures such that a major edge of the PCBs abuts the support structures.

4. The microphone assembly according to claim 3, wherein each of the first and second microphones has a respective pickup on a front surface of the PCB.

5. The microphone assembly according to claim 3 or 4, wherein the PCBs are mounted at an angle of between 39  and 49 to the longitudinal axis of the assembly.

6. The microphone assembly according to claim 5, wherein the PCBs are mounted at an angle of between 44  and 45 to the longitudinal axis of the assembly.

7. The microphone assembly according to any one of the preceding claims, wherein mutually engaging ends of the support structures form a hinge having a circular hollow hub, which accommodates the control circuit. - 9 -

8. The microphone assembly according to any one of claims 1 to 7, wherein the control circuit is enabled and the second support structure is rotated toward the first support structure so that the first and second microphones are oriented at an angle of between 80  to 100  with their respective pickups facing in opposite directions thereby creating an omnidirectional polar pattern for the combined assembly.

9. The microphone assembly according to any one of claims 1 to 7, wherein the control circuit is enabled and the second support structure is rotated toward the first support structure so that the first and second microphones are oriented at an angle of between 80  to 100  with their respective pickups facing in the same direction thereby creating a cardioid polar pattern where the two pickup hemispheres created by the first and second microphones overlap.

10. The microphone assembly according to any one of claims 1 to 7, wherein the control circuit is enabled and the first and second support structures are axially aligned to within ±10 along the longitudinal axis with their pickups directed outwards away from the pivot axis in opposing direction, thereby creating a sub-cardioid polar pattern were the two pickup hemispheres created by the microphones are partly overlapping.

11. The microphone assembly according to any one of claims 1 to 7, wherein: the control circuit is disabled, and the second support structure is rotated toward the first support structure so that the first and second microphones are oriented at an angle of between 80  to 100  with their respective pickups facing in the same direction thereby creating a cardioid polar pattern where the two pickup hemispheres created by the first and second microphones overlap; whereby the microphone assembly functions as two independent microphones. 25