EP0847674A2 - Musical instruments incorporating loudspeakers - Google Patents

Musical instruments incorporating loudspeakers

Info

Publication number
EP0847674A2
EP0847674A2 EP96929405A EP96929405A EP0847674A2 EP 0847674 A2 EP0847674 A2 EP 0847674A2 EP 96929405 A EP96929405 A EP 96929405A EP 96929405 A EP96929405 A EP 96929405A EP 0847674 A2 EP0847674 A2 EP 0847674A2
Authority
EP
European Patent Office
Prior art keywords
panel
radiator
musical instrument
electronic musical
loudspeaker
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP96929405A
Other languages
German (de)
French (fr)
Other versions
EP0847674B1 (en
Inventor
Henry Azima
Martin Colloms
Neil Harris
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NVF Tech Ltd
Original Assignee
Verity Group PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9517918.0A external-priority patent/GB9517918D0/en
Priority claimed from GBGB9522281.6A external-priority patent/GB9522281D0/en
Priority claimed from GBGB9606836.6A external-priority patent/GB9606836D0/en
Application filed by Verity Group PLC filed Critical Verity Group PLC
Publication of EP0847674A2 publication Critical patent/EP0847674A2/en
Application granted granted Critical
Publication of EP0847674B1 publication Critical patent/EP0847674B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
    • H04R1/028—Casings; Cabinets ; Supports therefor; Mountings therein associated with devices performing functions other than acoustics, e.g. electric candles
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/04—Plane diaphragms
    • H04R7/045—Plane diaphragms using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion

Definitions

  • the invention relates to musical instruments and more particularly to electronic keyboard musical instruments incorporating loudspeakers.
  • a panel-form loudspeaker comprising:- a resonant multi-mode radiator element being a unitary sandwich panel formed of two skins of material with a spacing core of transverse cellular construction, wherein the panel is such as to have ratio of bending stiffness (B) , in all orientations, to the cube power of panel mass per unit surface area ( ⁇ ) of at least 10; a mounting means which supports the panel or attaches to it a supporting body, in a free undamped manner; and an electro-mechanical drive means coupled to the panel which serves to excite a multi-modal resonance in the radiator panel in response to an electrical input within a working frequency band for the loudspeaker.
  • B bending stiffness
  • ⁇ cube power of panel mass per unit surface area
  • Embodiments of the present invention use members of nature, structure and configuration achievable generally and/or specifically by implementing teachings of our co- pending PCT application no. (our case P.5711) of even date herewith.
  • Such members thus have capability to sustain and propagate input vibrational energy by bending waves in operative area(s) extending transversely of thickness often but not necessarily to edges of the member(s); are configured with or without anisotropy of bending stiffness to have resonant mode vibration components distributed over said area(s) beneficially for acoustic coupling with ambient air; and have predetermined preferential locations or sites within said area for transducer means, particularly operationally active or moving part(s) thereof effective in relation to acoustic vibrational activity in said area(s) and signals, usually electrical, corresponding to acoustic content of such vibrational activity.
  • This invention is particularly concerned with electronic keyboard musical instruments incorporating active acoustic devices e.g. in the form of loudspeakers.
  • Active acoustic devices e.g. in the form of loudspeakers.
  • Members as above are herein called distributed mode radiators and are intended to be characterised as in the above PCT application and/or otherwise as specifically provided herein.
  • the invention is an electronic musical instrument having a keyboard, characterised by a loudspeaker comprising a distributed mode acoustic radiator and a transducer mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.
  • the radiator may comprise a stiff lightweight panel having a cellular core sandwiched by a pair of high modulus skins, a frame surrounding the panel and a resilient suspension supporting the panel on the frame.
  • the electrical musical instrument may have legs supporting the instrument above the ground and the radiator may be provided at the base of the instrument.
  • the loudspeaker may be positioned with the radiator substantially vertical.
  • the loudspeaker may form a ground support for the instrument.
  • Figure 1 is a diagram showing a distributed-mode loudspeaker as described and claimed in our co-pending International application No. (our case P.5711);
  • Figure 2a is a partial section on the line A-A of Figure 1;
  • Figure 2b is an enlarged cross-section through a distributed mode radiator of the kind shown in Figure 2a_ and showing two alternative constructions;
  • FIG 3 is a perspective diagram of a first embodiment of keyboard electronic instrument according to the present invention
  • Figure 4 is a plan view of the underside of the instrument of Figure 3;
  • Figure 5 is a partial cross-sectional view of the instrument of Figures 3 and 4, and
  • Figure 6 is a perspective view of a second embodiment of musical instrument according to the present invention.
  • Amplifier load impedance is largely resistive at 6 ohms, power handling 20-80 watts.
  • the panel core and/or skins are of metal, they may be made to act as a heat sink for the transducer to remove heat from the motor coil of the transducer and thus improve power handling.
  • Figures 2a. and 2b are partial typical cross-sections through the loudspeaker (81) of Figure 1.
  • Figure 2a. shows that the frame (1), surround (3) and panel (2) are connected together by respective adhesive-bonded joints (20) .
  • Suitable materials for the frame include lightweight framing, e.g. picture framing of extruded metal e.g. aluminium alloy or plastics.
  • Suitable surround materials include resilient materials such as foam rubber and foam plastics.
  • Suitable adhesives for the joints (20) include epoxy, acrylic and cyano-acrylate etc. adhesives.
  • Figure 2b illustrates, to an enlarged scale, that the panel (2) is a rigid lightweight panel having a core (22) e.g. of a rigid plastics foam (97) e.g. cross linked polyvinylchloride or a cellular matrix (98) i.e. a honeycomb matrix of metal foil, plastics or the like, with the cells extending transversely to the plane of the panel, and enclosed by opposed skins (21) e.g. of paper, card, plastics or metal foil or sheet.
  • the skins are of plastics, they may be reinforced with fibres e.g. of carbon, glass, Kevlar (RTM) or the like in a manner known per se to increase their modulus.
  • RTM Kevlar
  • Envisaged skin layer materials and reinforcements thus include carbon, glass, Kevlar (RTM), Nomex (RTM) i.e. aramid etc. fibres in various lays and weaves, as well as paper, bonded paper laminates, melamine, and various synthetic plastics films of high modulus, such as Mylar
  • Envisaged core layer materials include fabricated honeycombs or corrugations of aluminium alloy sheet or foil, or Kevlar (RTM), Nomex (RTM), plain or bonded papers, and various synthetic plastics films, as well as expanded or foamed plastics or pulp materials, even aerogel metals if of suitably low density.
  • Some suitable core layer materials effectively exhibit usable self-skinning in their manufacture and/or otherwise have enough inherent stiffness for use without lamination between skin layers.
  • a high performance cellular core material is known under the trade name 'Rohacell' which may be suitable as a radiator panel and which is without skins. In practical terms, the aim is for an overall lightness and stiffness suited to a particular purpose, specifically including optimising contributions from core and skin layers and transitions between them.
  • piezo and electro dynamic transducers have negligible electromagnetic radiation or stray magnet fields.
  • Conventional speakers have a large magnetic field, up to 1 metre distant unless specific compensation counter measures are taken.
  • electrical connection can be made to the conductive parts of an appropriate DML panel or an electrically conductive foam or similar interface may be used for the edge mounting.
  • the suspension (3) may damp the edges of the panel (2) to prevent excessive edge movement of the panel. Additionally or alternatively, further damping may be applied, e.g. as patches, bonded to the panel in selected positions to damp excessive movement to distribute resonance equally over the panel.
  • the patches may be of bitumen-based material, as commonly used in conventional loudspeaker enclosures or may be of a resilient or rigid polymeric sheet material. Some materials, notably paper and card, and some cores may be self-damping. Where desired, the damping may be increased in the construction of the panels by employing resiliently setting, rather than rigid setting adhesives.
  • Effective said selective damping includes specific application to the panel including its sheet material of means permanently associated therewith. Edges and corners can be particularly significant for dominant and less dispersed low frequency vibration modes of panels hereof. Edge-wise fixing of damping means can usefully lead to a panel with its said sheet material fully framed, though their corners can often be relatively free, say for desired extension to lower frequency operation. Attachment can be by adhesive or self-adhesive materials. Other forms of useful damping, particularly in terms of more subtle effects and/or mid- and higher frequencies can be by way of suitable mass or masses affixed to the sheet material at predetermined effective medial localised positions of said area.
  • An acoustic panel as described above is bi- directional.
  • the sound energy from the back is not strongly phase related to that from the front. Consequently there is the benefit of overall summation of acoustic power in the room, sound energy of uniform frequency distribution, reduced reflective and standing wave effects and with the advantage of superior reproduction of the natural space and ambience in the reproduced sound recordings.
  • the instrument is provided with a signal generator connected to the keys and with a signal amplifier which drives a loudspeaker.
  • the loudspeaker comprises a distributed mode acoustic radiator (81) of the kind shown in Figures 1 and 2, incorporating a stiff lightweight rectangular panel (2) mounted by its periphery in a frame (1) with an interposed resilient suspension (3) and driven by a transducer (9), all as described above with reference to Figures 1 and 2.
  • the loudspeaker (81) forms the base of the body (138) .
  • Figure 6 illustrates an electronic keyboard musical instrument, (137) very similar to that of Figures 3 to 5 having a body (138) having a keyboard (140) .
  • the body is supported on front legs (141) and is provided with a panel- form loudspeaker (81) to form the back support of the instrument.
  • the loudspeaker (81) comprises a rigid lightweight distributed mode acoustic radiator panel (2) mounted by its periphery in a surrounding resilient suspension (3) e.g. of foam rubber, the suspension being supported in a baffle ⁇ like frame (6), e.g. of medium density fibreboard.
  • a transducer (9) is attached to the panel (2) to launch bending waves into the panel to cause the panel to resonate to produce an acoustic output.
  • the arrangement is thus of the kind shown in Figures 1 and 2.
  • the transducer (9) will be driven by an amplifier (not shown) which is connected to receive signals produced by depression of the keys of the keyboard, in generally conventional fashion.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Electrophonic Musical Instruments (AREA)
  • Toys (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)

Abstract

An electronic musical instrument (137) having a keyboard (140), characterized by a loudspeaker (81) comprising a distributed mode acoustic radiator (2) and a transducer (9) mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.

Description

MUSICAL INSTRUMENTS INCORPORATING LOUDSPEAKERS
DESCRIPTION
TECHNICAL FIELD
The invention relates to musical instruments and more particularly to electronic keyboard musical instruments incorporating loudspeakers.
BACKGROUND ART It is known from GB-A-2262861 to suggest a panel-form loudspeaker comprising:- a resonant multi-mode radiator element being a unitary sandwich panel formed of two skins of material with a spacing core of transverse cellular construction, wherein the panel is such as to have ratio of bending stiffness (B) , in all orientations, to the cube power of panel mass per unit surface area (μ) of at least 10; a mounting means which supports the panel or attaches to it a supporting body, in a free undamped manner; and an electro-mechanical drive means coupled to the panel which serves to excite a multi-modal resonance in the radiator panel in response to an electrical input within a working frequency band for the loudspeaker.
DISCLOSURE OF INVENTION Embodiments of the present invention use members of nature, structure and configuration achievable generally and/or specifically by implementing teachings of our co- pending PCT application no. (our case P.5711) of even date herewith. Such members thus have capability to sustain and propagate input vibrational energy by bending waves in operative area(s) extending transversely of thickness often but not necessarily to edges of the member(s); are configured with or without anisotropy of bending stiffness to have resonant mode vibration components distributed over said area(s) beneficially for acoustic coupling with ambient air; and have predetermined preferential locations or sites within said area for transducer means, particularly operationally active or moving part(s) thereof effective in relation to acoustic vibrational activity in said area(s) and signals, usually electrical, corresponding to acoustic content of such vibrational activity. Uses are envisaged in co-pending International application No. (our file P.5711) of even date herewith for such members as or in "passive" acoustic devices without transducer means, such as for reverberation or for acoustic filtering or for acoustically "voicing" a space or room; and as or in "active" acoustic devices with transducer means, such as in a remarkably wide range of sources of sound or loudspeakers when supplied with input signals to be converted to said sound, or in such as microphones when exposed to sound to be converted into other signals.
This invention is particularly concerned with electronic keyboard musical instruments incorporating active acoustic devices e.g. in the form of loudspeakers. Members as above are herein called distributed mode radiators and are intended to be characterised as in the above PCT application and/or otherwise as specifically provided herein.
The invention is an electronic musical instrument having a keyboard, characterised by a loudspeaker comprising a distributed mode acoustic radiator and a transducer mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.
The radiator may comprise a stiff lightweight panel having a cellular core sandwiched by a pair of high modulus skins, a frame surrounding the panel and a resilient suspension supporting the panel on the frame.
The electrical musical instrument may have legs supporting the instrument above the ground and the radiator may be provided at the base of the instrument. The loudspeaker may be positioned with the radiator substantially vertical.
The loudspeaker may form a ground support for the instrument. BRIEF DESCRIPTION OF DRAWINGS The invention is diagrammatically illustrated, by way of example, in the accompanying drawings, in which:-
Figure 1 is a diagram showing a distributed-mode loudspeaker as described and claimed in our co-pending International application No. (our case P.5711);
Figure 2a is a partial section on the line A-A of Figure 1;
Figure 2b is an enlarged cross-section through a distributed mode radiator of the kind shown in Figure 2a_ and showing two alternative constructions;
Figure 3 is a perspective diagram of a first embodiment of keyboard electronic instrument according to the present invention; Figure 4 is a plan view of the underside of the instrument of Figure 3;
Figure 5 is a partial cross-sectional view of the instrument of Figures 3 and 4, and
Figure 6 is a perspective view of a second embodiment of musical instrument according to the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
Referring to Figure 1 of the drawings, there is shown a panel-form loudspeaker (81) of the kind described and claimed in our co-pending International application No.
(our case P.5711) of even date herewith comprising a rectangular frame (1) carrying a resilient suspension (3) round its inner periphery which supports a distributed mode sound radiating panel (2). A transducer (9) e.g as described in detail with reference to our co-pending
International applications Nos. (our cases P.5683/4/5) of even date herewith, is mounted wholly and exclusively on or in the panel (2) at a predetermined location defined by dimensions x and y., the position of which location is calculated as described in our co-pending International application No. (our case P.5711) of even date herewith, to launch bending waves into the panel to cause the panel to resonate to radiate an acoustic output. The transducer (9) is driven by a signal amplifier
(10), e.g. an audio amplifier, connected to the transducer by conductors (28) . Amplifier loading and power requirements can be entirely normal, similar to conventional cone type speakers, sensitivity being of the order of 86 - 88dB/watt under room loaded conditions.
Amplifier load impedance is largely resistive at 6 ohms, power handling 20-80 watts. Where the panel core and/or skins are of metal, they may be made to act as a heat sink for the transducer to remove heat from the motor coil of the transducer and thus improve power handling.
Figures 2a. and 2b are partial typical cross-sections through the loudspeaker (81) of Figure 1. Figure 2a. shows that the frame (1), surround (3) and panel (2) are connected together by respective adhesive-bonded joints (20) . Suitable materials for the frame include lightweight framing, e.g. picture framing of extruded metal e.g. aluminium alloy or plastics. Suitable surround materials include resilient materials such as foam rubber and foam plastics. Suitable adhesives for the joints (20) include epoxy, acrylic and cyano-acrylate etc. adhesives.
Figure 2b illustrates, to an enlarged scale, that the panel (2) is a rigid lightweight panel having a core (22) e.g. of a rigid plastics foam (97) e.g. cross linked polyvinylchloride or a cellular matrix (98) i.e. a honeycomb matrix of metal foil, plastics or the like, with the cells extending transversely to the plane of the panel, and enclosed by opposed skins (21) e.g. of paper, card, plastics or metal foil or sheet. Where the skins are of plastics, they may be reinforced with fibres e.g. of carbon, glass, Kevlar (RTM) or the like in a manner known per se to increase their modulus.
Envisaged skin layer materials and reinforcements thus include carbon, glass, Kevlar (RTM), Nomex (RTM) i.e. aramid etc. fibres in various lays and weaves, as well as paper, bonded paper laminates, melamine, and various synthetic plastics films of high modulus, such as Mylar
(RTM), Kaptan (RTM), polycarbonate, phenolic, polyester or related plastics, and fibre reinforced plastics, etc. and metal sheet or foil. Investigation of the Vectra grade of liquid crystal polymer thermoplastics shows that they may be useful for the injection moulding of ultra thin skins or shells of smaller size, say up to around 30cm diameter. This material self forms an orientated crystal structure in the direction of injection, a preferred orientation for the good propagation of treble energy from the driving point to the panel perimeter. Additional such moulding for this and other thermoplastics allows for the mould tooling to carry location and registration features such as grooves or rings for the accurate location of transducer parts e.g. the motor coil, and the magnet suspension. Additional with some weaker core materials it is calculated that it would be advantageous to increase the skin thickness locally e.g. in an area or annulus up to 150% of the transducer diameter, to reinforce that area and beneficially couple vibration energy into the panel. High frequency response will be improved with the softer foam materials by this means.
Envisaged core layer materials include fabricated honeycombs or corrugations of aluminium alloy sheet or foil, or Kevlar (RTM), Nomex (RTM), plain or bonded papers, and various synthetic plastics films, as well as expanded or foamed plastics or pulp materials, even aerogel metals if of suitably low density. Some suitable core layer materials effectively exhibit usable self-skinning in their manufacture and/or otherwise have enough inherent stiffness for use without lamination between skin layers. A high performance cellular core material is known under the trade name 'Rohacell' which may be suitable as a radiator panel and which is without skins. In practical terms, the aim is for an overall lightness and stiffness suited to a particular purpose, specifically including optimising contributions from core and skin layers and transitions between them. Several of the preferred formulations for the panel employ metal and metal alloy skins, or alternatively a carbon fibre reinforcement. Both of these, and also designs with an alloy Aerogel or metal honeycomb core, will have substantial radio frequency screening properties which should be important in several EMC applications. Conventional panel or cone type speakers have no inherent EMC screening capability.
In addition the preferred form of piezo and electro dynamic transducers have negligible electromagnetic radiation or stray magnet fields. Conventional speakers have a large magnetic field, up to 1 metre distant unless specific compensation counter measures are taken.
Where it is important to maintain the screening in an application, electrical connection can be made to the conductive parts of an appropriate DML panel or an electrically conductive foam or similar interface may be used for the edge mounting.
The suspension (3) may damp the edges of the panel (2) to prevent excessive edge movement of the panel. Additionally or alternatively, further damping may be applied, e.g. as patches, bonded to the panel in selected positions to damp excessive movement to distribute resonance equally over the panel. The patches may be of bitumen-based material, as commonly used in conventional loudspeaker enclosures or may be of a resilient or rigid polymeric sheet material. Some materials, notably paper and card, and some cores may be self-damping. Where desired, the damping may be increased in the construction of the panels by employing resiliently setting, rather than rigid setting adhesives.
Effective said selective damping includes specific application to the panel including its sheet material of means permanently associated therewith. Edges and corners can be particularly significant for dominant and less dispersed low frequency vibration modes of panels hereof. Edge-wise fixing of damping means can usefully lead to a panel with its said sheet material fully framed, though their corners can often be relatively free, say for desired extension to lower frequency operation. Attachment can be by adhesive or self-adhesive materials. Other forms of useful damping, particularly in terms of more subtle effects and/or mid- and higher frequencies can be by way of suitable mass or masses affixed to the sheet material at predetermined effective medial localised positions of said area.
An acoustic panel as described above is bi- directional. The sound energy from the back is not strongly phase related to that from the front. Consequently there is the benefit of overall summation of acoustic power in the room, sound energy of uniform frequency distribution, reduced reflective and standing wave effects and with the advantage of superior reproduction of the natural space and ambience in the reproduced sound recordings.
While the radiation from the acoustic panel is largely non-directional, the percentage of phase related information increases off axis. For improved focus for the phantom stereo image, placement of the speakers, like pictures, at the usual standing person height, confers the benefit of a moderate off-axis placement for the normally seated listener optimising the stereo effect. Likewise the triangular left/right geometry with respect to the listener provides a further angular component. Good stereo is thus obtainable. There is a further advantage for a group of listeners compared with conventional speaker reproduction. The intrinsically dispersed nature of acoustic panel sound radiation gives it a sound volume which does not obey the inverse square law for distance for an equivalent point source. Because the intensity fall-off with distance is much less than predicted by inverse square law then consequently for off-centre and poorly placed listeners the intensity field for the panel speaker promotes a superior stereo effect compared to conventional speakers. This is because the off-centre placed listener does not suffer the doubled problem due to proximity to the nearer speaker; firstly the excessive increase in loudness from the nearer speaker, and then the corresponding decrease in loudness from the further loudspeaker. There is also the advantage of a flat, lightweight panel-form speaker, visually attractive, of good sound quality and requiring only one transducer and no crossover for a full range sound from each panel diaphragm. Figures 3,4 and 5 illustrate an electronic keyboard musical instrument (137), e.g. a piano, comprising a body
(138) supported on ground engaging legs (139). The body
(138) is formed with a keyboard (140) by which the instrument is played.
In conventional fashion the instrument is provided with a signal generator connected to the keys and with a signal amplifier which drives a loudspeaker. In the present embodiment the loudspeaker comprises a distributed mode acoustic radiator (81) of the kind shown in Figures 1 and 2, incorporating a stiff lightweight rectangular panel (2) mounted by its periphery in a frame (1) with an interposed resilient suspension (3) and driven by a transducer (9), all as described above with reference to Figures 1 and 2. As shown, the loudspeaker (81) forms the base of the body (138) .
Figure 6 illustrates an electronic keyboard musical instrument, (137) very similar to that of Figures 3 to 5 having a body (138) having a keyboard (140) . The body is supported on front legs (141) and is provided with a panel- form loudspeaker (81) to form the back support of the instrument.
The loudspeaker (81) comprises a rigid lightweight distributed mode acoustic radiator panel (2) mounted by its periphery in a surrounding resilient suspension (3) e.g. of foam rubber, the suspension being supported in a baffle¬ like frame (6), e.g. of medium density fibreboard. A transducer (9), is attached to the panel (2) to launch bending waves into the panel to cause the panel to resonate to produce an acoustic output. The arrangement is thus of the kind shown in Figures 1 and 2. The transducer (9) will be driven by an amplifier (not shown) which is connected to receive signals produced by depression of the keys of the keyboard, in generally conventional fashion.

Claims

1. An electronic musical instrument having a keyboard, characterised by a loudspeaker comprising a distributed mode acoustic radiator and a transducer mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.
2. An electronic musical instrument according to claim 1, characterised in that the radiator comprises a stiff lightweight panel having a cellular core sandwiched by a pair of high modulus skins.
3. An electronic musical instrument according to claim 2, characterised by a frame surrounding the panel.
4. An electronic musical instrument according to claim 3, characterised by a resilient suspension supporting the panel on the frame.
5. An electronic musical instrument according to any preceding claim, characterised by legs supporting the instrument above the ground and in that the radiator is positioned at the base of the instrument.
6. An electronic musical instrument according to claim 5, characterised in that the loudspeaker is positioned with the radiator substantially vertical.
7. An electronic musical instrument according to claim 6, characterised in that the frame forms a ground support for the instrument.
EP96929405A 1995-09-02 1996-09-02 Musical instruments incorporating loudspeakers Expired - Lifetime EP0847674B1 (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
GB9517918 1995-09-02
GBGB9517918.0A GB9517918D0 (en) 1995-09-02 1995-09-02 Acoustic device
GBGB9522281.6A GB9522281D0 (en) 1995-10-31 1995-10-31 Acoustic device
GB9522281 1995-10-31
GB9606836 1996-03-30
GBGB9606836.6A GB9606836D0 (en) 1996-03-30 1996-03-30 Acoustic device
PCT/GB1996/002164 WO1997009857A2 (en) 1995-09-02 1996-09-02 Musical instruments incorporating loudspeakers

Publications (2)

Publication Number Publication Date
EP0847674A2 true EP0847674A2 (en) 1998-06-17
EP0847674B1 EP0847674B1 (en) 1999-04-28

Family

ID=34865250

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96929405A Expired - Lifetime EP0847674B1 (en) 1995-09-02 1996-09-02 Musical instruments incorporating loudspeakers

Country Status (20)

Country Link
EP (1) EP0847674B1 (en)
JP (1) JPH11512259A (en)
AT (1) ATE179564T1 (en)
AU (1) AU703004B2 (en)
BR (1) BR9610437A (en)
CA (1) CA2230154A1 (en)
CZ (1) CZ58198A3 (en)
DE (1) DE69602281T2 (en)
DK (1) DK0847674T3 (en)
EA (1) EA002375B1 (en)
ES (1) ES2133996T3 (en)
HK (1) HK1008643A1 (en)
HU (1) HUP9903872A2 (en)
IL (1) IL123481A (en)
NZ (1) NZ316562A (en)
PL (1) PL182641B1 (en)
RO (1) RO119053B1 (en)
SK (1) SK26298A3 (en)
TR (1) TR199800359T1 (en)
WO (1) WO1997009857A2 (en)

Families Citing this family (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2336072A1 (en) 1998-06-22 1999-12-29 Slab Technology Limited Loudspeakers
GB0414082D0 (en) * 2004-06-24 2004-07-28 New Transducers Ltd Bending wave devices
US11431312B2 (en) 2004-08-10 2022-08-30 Bongiovi Acoustics Llc System and method for digital signal processing
US10158337B2 (en) 2004-08-10 2018-12-18 Bongiovi Acoustics Llc System and method for digital signal processing
US10848118B2 (en) 2004-08-10 2020-11-24 Bongiovi Acoustics Llc System and method for digital signal processing
US8284955B2 (en) 2006-02-07 2012-10-09 Bongiovi Acoustics Llc System and method for digital signal processing
US9615189B2 (en) 2014-08-08 2017-04-04 Bongiovi Acoustics Llc Artificial ear apparatus and associated methods for generating a head related audio transfer function
US11202161B2 (en) 2006-02-07 2021-12-14 Bongiovi Acoustics Llc System, method, and apparatus for generating and digitally processing a head related audio transfer function
US10701505B2 (en) 2006-02-07 2020-06-30 Bongiovi Acoustics Llc. System, method, and apparatus for generating and digitally processing a head related audio transfer function
US10069471B2 (en) 2006-02-07 2018-09-04 Bongiovi Acoustics Llc System and method for digital signal processing
US10848867B2 (en) 2006-02-07 2020-11-24 Bongiovi Acoustics Llc System and method for digital signal processing
US8502062B2 (en) 2010-07-12 2013-08-06 Yamaha Corporation Electronic keyboard musical instrument
JP5659617B2 (en) * 2010-08-11 2015-01-28 ヤマハ株式会社 Electronic keyboard instrument
JP5703612B2 (en) * 2010-07-12 2015-04-22 ヤマハ株式会社 Electronic keyboard instrument
US9264004B2 (en) 2013-06-12 2016-02-16 Bongiovi Acoustics Llc System and method for narrow bandwidth digital signal processing
US9883318B2 (en) 2013-06-12 2018-01-30 Bongiovi Acoustics Llc System and method for stereo field enhancement in two-channel audio systems
US9906858B2 (en) 2013-10-22 2018-02-27 Bongiovi Acoustics Llc System and method for digital signal processing
US10639000B2 (en) 2014-04-16 2020-05-05 Bongiovi Acoustics Llc Device for wide-band auscultation
US10820883B2 (en) 2014-04-16 2020-11-03 Bongiovi Acoustics Llc Noise reduction assembly for auscultation of a body
US9615813B2 (en) 2014-04-16 2017-04-11 Bongiovi Acoustics Llc. Device for wide-band auscultation
US9564146B2 (en) 2014-08-01 2017-02-07 Bongiovi Acoustics Llc System and method for digital signal processing in deep diving environment
US9638672B2 (en) 2015-03-06 2017-05-02 Bongiovi Acoustics Llc System and method for acquiring acoustic information from a resonating body
US9906867B2 (en) 2015-11-16 2018-02-27 Bongiovi Acoustics Llc Surface acoustic transducer
US9621994B1 (en) 2015-11-16 2017-04-11 Bongiovi Acoustics Llc Surface acoustic transducer
CA3096877A1 (en) 2018-04-11 2019-10-17 Bongiovi Acoustics Llc Audio enhanced hearing protection system
WO2020028833A1 (en) 2018-08-02 2020-02-06 Bongiovi Acoustics Llc System, method, and apparatus for generating and digitally processing a head related audio transfer function

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4392027A (en) * 1978-05-05 1983-07-05 Messerschmitt-Boelkow-Blohm Gesellschaft Mit Beschraenkter Haftung Method and apparatus for providing a uniform sound distribution in an aircraft cabin

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3247925A (en) * 1962-03-08 1966-04-26 Lord Corp Loudspeaker
JPS5748153Y2 (en) * 1977-11-26 1982-10-22
EP0434754A1 (en) * 1988-09-14 1991-07-03 Wilhelm Schimmel Pianofortefabrik Gmbh Sound radiation device and musical instrument
DE3940612A1 (en) * 1988-12-10 1990-06-13 Hans Guenter Hofmann Housing for electronic home organ - has drawer spaces for electronic units, cloth-covered loudspeaker enclosures and amplifier housing
WO1992003024A1 (en) * 1990-08-04 1992-02-20 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Panel-form loudspeaker
JP2595789Y2 (en) * 1992-03-24 1999-06-02 株式会社河合楽器製作所 Speaker device for electronic keyboard instrument

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4392027A (en) * 1978-05-05 1983-07-05 Messerschmitt-Boelkow-Blohm Gesellschaft Mit Beschraenkter Haftung Method and apparatus for providing a uniform sound distribution in an aircraft cabin

Also Published As

Publication number Publication date
PL182641B1 (en) 2002-02-28
EA199800255A1 (en) 1998-10-29
DK0847674T3 (en) 1999-10-25
ES2133996T3 (en) 1999-09-16
WO1997009857A2 (en) 1997-03-13
IL123481A (en) 2000-10-31
NZ316562A (en) 1998-05-27
EA002375B1 (en) 2002-04-25
JPH11512259A (en) 1999-10-19
DE69602281D1 (en) 1999-06-02
RO119053B1 (en) 2004-02-27
ATE179564T1 (en) 1999-05-15
PL325245A1 (en) 1998-07-06
AU703004B2 (en) 1999-03-11
TR199800359T1 (en) 1998-05-21
BR9610437A (en) 1999-02-17
HUP9903872A2 (en) 2000-03-28
CZ58198A3 (en) 1998-07-15
DE69602281T2 (en) 1999-09-16
SK26298A3 (en) 1998-09-09
AU6882096A (en) 1997-03-27
EP0847674B1 (en) 1999-04-28
HK1008643A1 (en) 1999-05-14
IL123481A0 (en) 1998-09-24
CA2230154A1 (en) 1997-03-13

Similar Documents

Publication Publication Date Title
US6243473B1 (en) Laptop computer with loudspeaker(s)
US6198831B1 (en) Panel-form loudspeakers
AU703122B2 (en) Panel-form loudspeakers
US6144746A (en) Loudspeakers comprising panel-form acoustic radiating elements
US6031926A (en) Panel-form loudspeakers
EP0847674B1 (en) Musical instruments incorporating loudspeakers
AU702999B2 (en) A portable compact disc player
EP0847671B1 (en) Personal computers
US6351542B2 (en) Loudspeakers with panel-form acoustic radiating elements
WO1997009840A2 (en) Loudspeakers comprising panel-form acoustic radiating elements
AU6881696A (en) Inertial vibration transducers
AU6880996A (en) Visual display means incorporating loudspeakers
EP0847664A2 (en) Loudspeakers comprising panel-form acoustic radiating elements
WO1997009849A1 (en) Loudspeakers with panel-form acoustic radiating elements
AU6880696A (en) Packaging
US6327369B1 (en) Loudspeakers comprising panel-form acoustic radiating elements
US6201878B1 (en) Portable compact disc player
US6399870B1 (en) Musical instruments incorporating loudspeakers
WO1997009847A1 (en) Panel-form loudspeakers
US6169809B1 (en) Visual display means incorporating loudspeakers
US6404894B1 (en) Packaging

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19980318

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL PAYMENT 980318;LT PAYMENT 980318;LV PAYMENT 980318;SI PAYMENT 980318

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

17Q First examination report despatched

Effective date: 19980701

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: NEW TRANSDUCERS LIMITED

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

ITF It: translation for a ep patent filed
AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL PAYMENT 19980318;LT PAYMENT 19980318;LV PAYMENT 19980318;SI PAYMENT 19980318

LTIE Lt: invalidation of european patent or patent extension
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19990428

Ref country code: LI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19990428

Ref country code: GR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990428

Ref country code: CH

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19990428

REF Corresponds to:

Ref document number: 179564

Country of ref document: AT

Date of ref document: 19990515

Kind code of ref document: T

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69602281

Country of ref document: DE

Date of ref document: 19990602

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990902

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2133996

Country of ref document: ES

Kind code of ref document: T3

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

REG Reference to a national code

Ref country code: PT

Ref legal event code: SC4A

Free format text: AVAILABILITY OF NATIONAL TRANSLATION

Effective date: 19990709

Ref country code: CH

Ref legal event code: PL

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000331

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20010810

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20010813

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DK

Payment date: 20010814

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20010817

Year of fee payment: 6

Ref country code: FI

Payment date: 20010817

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20010820

Year of fee payment: 6

Ref country code: DE

Payment date: 20010820

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: PT

Payment date: 20010823

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IE

Payment date: 20010828

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20010914

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20010920

Year of fee payment: 6

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020902

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020902

Ref country code: FI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020902

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020902

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020903

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020930

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020930

BERE Be: lapsed

Owner name: *NEW TRANSDUCERS LTD

Effective date: 20020930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030401

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030401

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20020902

REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030603

REG Reference to a national code

Ref country code: PT

Ref legal event code: MM4A

Free format text: LAPSE DUE TO NON-PAYMENT OF FEES

Effective date: 20030331

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20031011

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050902