A compressed air load audio source and a method for generating sound

Abstract

The present invention belongs to the field of systems for transmitting sound. The invention relates to a compressed air load audio source and to a method for generating holographic sound. The compressed air load audio source comprises - a transducer comprising a perforated tube a membrane installed on said perforated tube with gaskets or O-rings, - an airtight structure cabinet, wherein said perforated tube is mounted on the cabinet and connected to the latter through an output connection, and wherein the cabinet encloses the following components: o at least one pair of speakers each hermetically installed in its own cavity, wherein the central cavity between them is empty and arranged for communication with the membrane M1 through the micro-perforated tube F1, wherein said speakers S1, S2 are connectable to an external amplifier, o a plurality of pressurized cavities C1, C2, C3 separated from each other and each provided with its own valve V1, V2, V3 connectable to an air compressor via a flexible tube T1, wherein the pressure in said cavities C1, C2, C3 is the same as the pressure inside the membrane M1, and wherein the number of cavities is the number of speakers + 1, and o at least two pairs of connectors B1, B2 for amplifier connection.

Description

[0001] A COMPRESSED AIR LOAD AUDIO SOURCE AND A METHOD FOR GENERATING SOUND

[0002] Field and the object of the invention

[0003] The present invention belongs to the field of systems for generating sound using circular waves, more precisely to the field of loudspeakers. The invention relates to a compressed air load audio source and to a method for generating sound. The present solution is intended to satisfy the needs in the field of music, cinema, or other applications of holographic sound.

[0004] Background of the invention and the technical problem

[0005] A loudspeaker or a speaker is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. The loudspeaker usually comprises one or more such speaker drivers, an enclosure, and electrical connections possibly including a crossover network. The majority of speakers are equipped with cones, domes, or flat membranes that, under the action of electromagnetic or electrostatic forces, produce incoherent sound waves. Ideally, sound should be emitted from a point source that propagates circular waves around itself. The technical problem is therefore construction of an audio source capable of achieving a single-point sound emission or close to this emission type.

[0006] Prior art

[0007] As mentioned above, known solutions use cones, domes or flat membranes to produce sound waves. None of the solutions known to the inventors achieves sound generation in the same manner as the present invention. Description of the invention

[0008] The present invention addresses the technical problem of generating sound in a different manner as presently known loudspeakers. The technical problem is solved as defined in the independent claims, wherein the preferred embodiments are defined in dependent claims.

[0009] The audio source according to the invention comprises:

[0010] - an ell iptical ly shaped transducer comprising a holder or preferably perforated tube on which a very thin latex or other elastomer membrane capable of flexibly and securely responding to volume variations is mounted with any suitable attachment means, such as gaskets or o-rings, wherein the membrane forms the elliptical shape and encloses a pressure-dependent air volume, and wherein the membrane covers a very wide range of sound frequencies and acoustic levels, preferably from 12Hz to 20 kHz, most preferably from 16 Hz to 16 kHz,

[0011] - optionally a protection of the transducer, preferably comprising a protective acoustic cloth and optionally other components known to the skilled person, said protection protecting the transducer against damage or any external effects on the membrane,

[0012] - an airtight (i.e. , sealed from external environment in any suitable manner known to the skilled person) structure cabinet made from any suitable material, wherein said holder or the perforated tube is mounted on the cabinet and connected to the latter through an output connection, which is designed as an orifice (or a hole) for pressure communication of the transducer with the central cavity of the solid cabinet, and wherein the cabinet encloses the following components: o a plurality of pressurized cavities, wherein

[0013] ■ the number of cavities is the number of speakers + 1 central cavity,

[0014] ■ said central cavity comprising no speaker, but is submissive, i.e. assembled with (attached to) all cavities comprising speakers,

[0015] ■ wherein said speaker-comprising cavities are symmetrically arranged and separated from each other and the central cavity with the membrane of the loudspeakers installed in the cavities, and ■ each cavity is provided with its own valve, wherein said valves are connectable to a flexible tube, and the valves are configured to allow them to be pressurized to identical values using an air compressor, which causes the membrane to swell in an elliptical shape, and

[0016] ■ wherein the pressure in said cavities is the same as the pressure inside the membrane, which is controlled with an external air compressor, o at least one pair of speakers, preferably electrodynamic speakers, each hermetically installed in its own cavity, wherein said speakers are connectable to an external amplifier in a one-channel manner, so that all speakers receive the same signal from the amplifier, o the central cavity arranged for communication with the membrane through the output connection and / or the perforated tube, o two pairs of connectors (binding posts) for amplifier connection,

[0017] - and optionally an external air compressor connectable to the cavities with a flexible tube, wherein the compressor ensures equal pressures inside said cavities and the elliptical membrane, so that the speakers are in neutral position (i.e. resting position of speaker drivers).

[0018] The whole construction of the cabinet is air-sealed from outside environment and airpressurized inside the central cavity and the cavities are air sealed from each other.

[0019] The pressurized cavities are equipped with valves to allow them to be pressurized to identical values using the air compressor. The latter is preferably automatic, i.e. externally controlled to ensure and adjust the pressure inside cavities and the membrane. The air pressure should be equal between the cavities so the membranes of the two speakers can move freely (i.e., back and forth). Furthermore, when all cavities have the same pressure before turning on the amplifier, the speakers are in resting position. In case one chamber has different pressure, the speaker driver is not in the neutral position as the other ones, as the pressure affects the driver position. The pressure of the air inside the membrane ensured by the compressor creates a better medium to move the waves if compared to an environment with less dense air. At the same time the air compressor ensures the membrane has sufficient tension for the sound waves to be created. If there is not enough tension, the sound is distorted, hence the equal pressures.

[0020] According to a possible embodiment, one pair of speakers is used and consequently three cavities are provided. One speaker is arranged in a left cavity and one speaker is arranged in a right cavity, wherein the central cavity is provided between the left and the right cavities.

[0021] According to another possible embodiment, two pairs of speakers are used and consequently there are five cavities provided. The speakers may be arranged symmetrically in a form of a cross, wherein the central cavity is in the central of the cross, or the two pairs of speakers are installed opposite each other. All other particulars are as described above.

[0022] The perforated tube may be any solid tube of any material, which has perforations achieved in any manner. The shapes and sizes of holes, their arrangement and distribution are arbitrary. The perforated tube keeps the membrane stable and steady, while the waves of air pulses from the structure housing reach the membrane through said perforations. Thus, the perforations transmit the air movement and the membrane consequently inflates and deflates in the rhythm of the air pulses emitted by the speakers. Namely, under the action of the amplified audio signal, the speakers move and thus expand and contract the volume of the air present inside the elliptical membrane. The holder, which may be used instead of the perforated tube, may be without perforations or openings, but then the connection to the central cavity has to allow inflating and deflating of the membrane based on air pulses created by every loudspeaker in the sound source according to the invention. Such connection may be achieved by a small perforated plate installed in the bottom part of the holder and connected to the membrane.

[0023] The sound from every loudspeaker is created from the movement of the membrane of their speaker, moving back and forth in a linear direction. In the present invention, the two speakers are installed opposite in closed / sealed boxes on their back side. The front side of the speakers will cancel the sound from each other but will generate the waves of the air that will be created from the elliptical membrane, which will be pressurized with air and will generate a holographic sound. The arrangement of the speakers makes the enclosures silent. Indeed, the sounds emitted in opposite phases cancel each other. Also, since mechanical actions are opposite vibrations are reduced to nothing. Therefore, it is the variation in volume of the elliptical membrane that, through the action of the speakers, reproduces sound in the open air. Namely, the elliptical membrane forming a holographic transducer is driven by the variation in volume of air confined in the elliptical membrane. This membrane is driven by the modulation of pressures and depressions generated by two speakers housed in pressurized enclosures. At equal pressure, these speakers are spaced facing each other in the common cavity. The elliptical membrane is the only part that can emit sound, as the enclosure is made silent due to the overall configuration. The movement of the speakers is affecting the volume of the elliptical membrane (inflating, deflating) with the rhythm of the variation of pressures that is created by the speakers and diffused in air pulses. The speakers will keep moving back and forth because of their electromagnetic systems and will keep moving according to the music / signals from the amplifier.

[0024] The pressure created by the speaker-cones, while moving back and forth, drives the air volume inside the elliptical membrane, and generate circular sound waves, while conventional speakers generate linear sound waves. As the structure with speakers are sealed from outside environment, the only way to transmit the waves / music is through the elliptical membrane. The music will be created / generated and spread to the air / environment in every direction in a holographic manner.

[0025] The method of generating sound in the sound source as described above thus comprises the following steps: a) connecting the speakers to an amplifier, b) pressurizing all cavities and the elliptical membrane according to the invention with the air compressor or in any other suitable manner and closing the valves, c) turning on the amplifier to cause movement induced by the speaker-drivers, thus leading to pulse waves (air movement), d) transmitting pulse waves created in the previous step through the central cavity and the holder or the perforated tube to the elliptical membrane, e) inflating and deflating of the elliptical membrane in accordance with the in the rhythm of the pulses created by the speakers, f) creating / generating sound by the activity in the previous steps, and g) spreading of the generated sound to the air / environment in every direction in a holographic manner, h) repeating the steps from d) to g) for as long as the sound needs to be generated. The steps a) and b) can be performed in any order.

[0026] In the present invention, a full range sound system is described. Knowing the size and specifications of the speaker-drivers, the frequency range for the composition of multiway systems can be determined.

[0027] This invention represents a single reproduction channel, wherein holographic, i.e. omnidirectional sound waves are generated, which create direct and reflecting sounds. The invention is low cost and has easy reproduction process. A usual stereophonic application requires two elements of this type. The number of these elements can be extended for cinematographic applications, including for extreme low-frequency transducers called "subwoofers".

[0028] Brief description of the figures

[0029] The invention will be described in further detail based on exemplary embodiments and figures, which show:

[0030] Figure 1 A simplified general cross-sectional view of a first embodiment of the device and the elements used in the exemplary embodiment of the sound source according to the invention

[0031] Figure 2 Examples of speaker connections

[0032] Figure 3 A second embodiment of the device with two pairs of speakers installed opposite one from another pair Figure 4 A side view of a third embodiment of the device with four speakers arranged in a symmetrical manner

[0033] Figure 5 A top view of the third embodiment shown in figure 4

[0034] Detailed description of the invention

[0035] As illustrated in Figure 1 , the sound source according to the invention comprises:

[0036] - an elliptically shaped transducer comprising: o a perforated tube F1 , o a very thin latex or other elastomer membrane M1 installed on said perforated tube F1 , wherein the membrane M1 is mounted with o-rings J1 , J2,

[0037] - a rectangular airtight structure cabinet K1 made from any suitable material, wherein said perforated tube F1 is mounted on the cabinet K1 and connected to the latter through an output connection R1 , which is designed as an orifice for pressure communication of the transducer with the central cavity C2 of the cabinet K1 , and wherein the cabinet K1 encloses the following components: o three pressurized cavities C1 , C2, C3 separated from each other and each provided with its own valve V1 , V2, V3, wherein said valves V1 , V2, V3 are connectable to a flexible tube T1 , and the valves V1 , V2, V3 are configured to allow them to be pressurized to identical values using an air compressor Z1 , which causes the membrane M1 to swell in an elliptical shape, and wherein the pressure in said cavities C1 , C2, C3 is the same as the pressure inside the membrane M1 , which is controlled with the external air compressor Z1 , and wherein the pressure is preferably above 1100 hPa (1 atm), o two speakers S1 , S2, preferably electrodynamic speakers, each hermetically installed in its own cavity C1 , C3, wherein the central cavity C2 between them is empty, wherein said speakers S1 , S2 are connectable to an external amplifier (not shown in the figure), o the central cavity C2 arranged for communication with the membrane M1 through the micro-perforated tube F1 , o Two pairs of connectors (binding posts) B1 , B2 for amplifier connection,

[0038] - and optionally an external air compressor Z1 connectable to the cabinet with the flexible tube T1 , wherein the compressor Z1 ensures equal pressures inside said cavities C1 , C2, C3 and the membrane M1 , so that the speakers S1 , S2 are in neutral position.

[0039] The transducer may be protected with a protection comprising an acoustic cloth that allows the sound to pass transparently through the fabric. The protection may have further supporting frames or similar structures to allow easier installation and reliable positioning of the acoustic cloth.

[0040] Figure 2 shows different speaker connections.

[0041] Figure 3 shows a one channel modular double speaker comprising four, i.e. two pairs of speakers installed in a rectangularly shaped cabinet, wherein one pair is in one row and the second pair is in a row above the first pair, wherein the central cavity is in the centre and along the whole height of the cabinet.

[0042] Figures 4 and 5 show a sound source according to a third possible embodiment, wherein four speakers are used and there are five cavities arranged in a cross-like formation as shown in figure 5, wherein the central cavity is centrally located and it is connected to one speaker-comprising cavity on each of the sides of the central cavity. The pressures in cavities are P1 is equal to P3, P4 and P5 as well as P2+P2’. As there are five cavities, there are five valves V1 to V5 each for its own cavity, wherein the central cavity is C2 as in the first embodiment.

[0043] Under the action of an amplified audio signal, the speakers create air pulses and these are through the central cavity and the tube responsible for contractions and inflations of the volume of air present in the elliptical membrane, which thus creates and emits holographic sound. The method of generating sound with the sound source as described above thus comprises the following steps: a) connecting the speakers to an amplifier, b) pressurizing all cavities of the invention with the air compressor, c) turning on the speakers to generate waves, d) transmitting air movements generated in the previous step through the central cavity and the perforated tube to the elliptical membrane, e) inflating and deflating of the elliptical membrane in accordance with the rhythm of the air movements created by the speakers-drivers, f) creating / generating holographic sound by the activity in the previous step, and g) spreading of the generated sound to the air / environment in every direction in a 3D sound stage, h) repeating the steps from d) to g) for as long as the sound needs to be generated.

Claims

Patent claims1 . A compressed air load audio source comprising- a transducer comprising: o a holder or a perforated tube (F1 ), o a membrane (M1 ) installed on said holder or the perforated tube (F1 ) with suitable attachment means (J1 , J2), wherein the membrane forms an elliptical shape and encloses a pressure-dependent air volume,- an airtight structure cabinet (K1 ), wherein said holder or the perforated tube (F1 ) is mounted on the cabinet (K1 ) and connected to the latter through an output connection (R1 ), and wherein the cabinet (K1 ) encloses the following components: o a plurality of pressurized cavities (C1 , C2, C3), wherein:■ the number of cavities is the number of speakers + 1 central cavity (C2),■ said central cavity (C2) comprising no speaker (S1 , S2), but is assembled with all cavities (C1 , C3) comprising speakers (S1 , S2),■ wherein said speaker-comprising cavities (C1 , C3) are symmetrically arranged and separated from each other and the central cavity (C2) with the membrane of the speakers installed in the cavities, and■ each cavity (C1 , C2, C3) is provided with its own valve, wherein said valves (V1 , V2, V3) are connectable to a flexible tube (F1 ), and the valves (V1 , V2, V3) are configured to allow them to be pressurized to identical values using an external air compressor, which causes the membrane (M1 ) to swell in an elliptical shape, and■ wherein the pressure in said cavities (C1 , C2, C3) is the same as the pressure inside the membrane (M1 ), which is controllable with the external air compressor,o at least one pair of speakers (S1 , S2), preferably electrodynamic speakers, each hermetically installed in its own cavity, wherein said speakers are connectable to an external amplifier in a one-channel manner, so that all speakers receive the same signal from the amplifier, o the central cavity arranged for communication with the membrane through the output connection and / or the perforated tube, o two pairs of connectors (binding posts) for amplifier connection.

2. The compressed air load audio source according to claim 1 , wherein the audio source further comprises an external air compressor (Z1 ) connected to the cabinet with a flexible tube (T1 ), wherein the compressor (Z1 ) ensures equal pressures inside said cavities (C1 , C2, C3) and the membrane (M1 ), so that the speakers (S1 , S2) are in neutral position.

3. The compressed air load audio source according to claim 2, wherein the air compressor (Z1 ) is arranged to cause the membrane (M1 ) to swell into an elliptical shape.

4. The compressed air load audio source according to any of the preceding claims, wherein the pressure is above 1100 hPa (1 atm).

5. The compressed air load audio source according to any of the preceding claims, wherein the membrane (M1 ) is a very thin latex or other elastomer membrane.

6. The compressed air load audio source according to any of the preceding claims, wherein the membrane covers a very wide range of sound frequencies and acoustic levels from 12Hz to 20 kHz, most preferably from 16 Hz to 16 kHz.

7. The compressed air load audio source according to any of the preceding claims, wherein the attachment means (J1 , J2) are gaskets or o-rings.

8. The compressed air load audio source according to any of the preceding claims, wherein the output connection (R1 ) is designed as an orifice for pressure communication of the transducer with the central cavity (C2) of the cabinet (K1 ).

9. The compressed air load audio source according to any of the preceding claims, wherein the speakers (S1 , S2) are electrodynamic speakers.

10. The compressed air load audio source according to any of the preceding claims, wherein the audio source further comprises a protection of the transducer for protecting the transducer against damage or any external effects on the membrane.

11. The compressed air load audio source according to the preceding claim, wherein the protection comprises a protective acoustic cloth and optionally supporting elements.

12. The compressed air load audio source according to any of the preceding claims, wherein the audio source comprises one pair of speakers and three cavities, wherein one speaker is arranged in a left cavity and one speaker is arranged in a right cavity, wherein the central cavity is provided between the left and the right cavities.

13. The compressed air load audio source according to any claim from 1 to 11 , wherein the audio source comprises two pairs of speakers and five cavities, wherein the speakers may be arranged symmetrically in a form of a cross, wherein the central cavity is in the central of the cross, or the two pairs of speakers are installed opposite each other.

14. The compressed air load audio source according to any of the preceding claims, wherein the audio source comprises the perforated tube, which is designed as any solid tube of any material, which has perforations achieved in any manner, wherein the shapes and sizes of holes, their arrangement and distribution are arbitrary.

15. The compressed air load audio source according to any claim from 1 to 13, wherein the audio source comprises the holder without perforations or openings, but thenthe connection to the central cavity has to allow inflating and deflating of the elliptical membrane based on air pulses generated by every speaker-driver in the central cavity, wherein said connection is a small perforated plate installed in the bottom part of the holder and connected to the membrane.

16. A method for generating sound using the compressed air load audio source according to any of the preceding claims, characterized in that the method comprises the following steps: a) connecting the speakers (S1 , S2) to an amplifier, b) pressurizing all cavities (C1 , C2, C3) of the sound source with the air compressor (Z1 ) or in any other suitable manner and closing the valves (V1 , V2, V3), c) turning on on the amplifier to cause movement of the speaker-drivers, thus leading to pulse waves, d) transmitting pulse waves generated in the previous step through the central cavity (C2) and the output connection and / or the perforated tube (F1 ) to the elliptical membrane (M1 ), e) inflating and deflating of the membrane (M1 ) in accordance with the rhythm of the pulse waves generated by the speaker-drivers (S1 , S2), f) creating / generating sound by the activity in the previous step, and g) spreading of the generated sound to the air / environment in every direction in a holographic manner, h) repeating the steps from d) to g) for as long as the sound needs to be generated, i) wherein steps a) and b) can be performed in any order.

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