Audio systems and methods employing an array of transducers optimized for particular sound frequencies
Systems and methods for generating sound, detecting sound, and generating and detecting sound are provided. An array of audio transducers can be provided whereby each audio transducer in the array can be optimized for a narrow range of sound frequencies. When operating at or close to its resonant frequency, a transducer can generate (and/or detect) sound with a higher efficiency and less distortion as compared to other frequencies. Accordingly, sound may be divided into component signals such that each transducer is only responsible for generating (and/or detection) sound close to its resonant frequency. This sound reproduction (and/or detection) technique can increase efficiency, and therefore, can increase the total output volume that an array can generate using a given amount of input power when generating sound (and/or increase the total output power that an array can generate using a given amount of input volume when detecting sound).
1. An array of transducers, comprising:
a plurality of transducers, each transducer comprising:
a diaphragm;
a conductive path located on a first side of the diaphragm; and
a cavity located beneath a second side of the diaphragm;
a substrate, wherein the diaphragm of each transducer of the plurality of transducers is located on a first side of the substrate; and
electrically conductive plating located on a second side of the substrate that is opposite the first side of the substrate, wherein the electrically conductive plating is electrically charged causing an electrical potential to be applied to at least one transducer's conductive path, thereby displacing the at least one transducer's diaphragm.
2. The array of transducers of claim 1 , wherein the diaphragm of the at least one transducer is displaced by electrical induction, which causes a sound wave to be generated.
3. The array of transducers of claim 1 , wherein each transducer's cavity is formed within the substrate.
4. The array of transducers of claim 3 , wherein at least one transducer of the plurality of transducers has its cavity formed within the substrate by etching away at least a portion of the substrate.
5. The array of transducers of claim 1 , wherein:
the substrate is a silicon substrate; and
at least one transducer's diaphragm is a polymer membrane.
6. The array of transducers of claim 1 , wherein at least one transducer of the array of transducers further comprises:
at least one acoustic port.
7. The array of transducers of claim 6 , wherein the at least one acoustic port extends from the at least one transducer's cavity through the electrically conductive plating.
8. The array of transducers of claim 6 , wherein the at least one acoustic port is formed by etching away at least a portion of the substrate.
9. The array of transducers of claim 1 , wherein the diaphragm of at least one transducer of the plurality of transducers is flexible.
10. The array of transducers of claim 9 , wherein at least one of:
the diaphragm is formed of a highly flexible material, such that the at least one transducer has a high resonant frequency; and
the diaphragm is formed of a stiffer material, such that the at least one transducer has a low resonant frequency.
11. The array of transducers of claim 1 , wherein a resonant frequency of at least one transducer of the plurality of transducers is a function of a size of that at least one transducer's cavity.
12. The array of transducers of claim 11 , wherein at least one transducer of the plurality of transducers further comprises at least one acoustic port, the resonant frequency of that at least one transducer is further a function of:
a size of the at least one acoustic port of that at least one transducer; and
a number of acoustic ports that at least one transducer includes.
13. The array of transducers of claim 1 , further comprising:
at least one control line coupled to each transducers conductive path.
14. The array of claim 13 , wherein the at least one control line comprises:
an active conductor and a return conductor.
15. A transducer within an array of transducers, comprising:
a diaphragm;
a conductive path that is at least one: of coupled to, and integrated into the diaphragm, the conductive path being located on a first side of the diaphragm;
a control line coupled to the conductive path; and
a cavity located beneath the diaphragm, wherein:
the diaphragm is located on a first side of a substrate; and
electrically conductive plating is located on a second side of the substrate that is opposite the first side of the substrate, wherein:
the electrically conductive plating is electrically charged causing current flowing through the transducer's conductive path to be altered and an electric signal to be generated via electromagnetic induction; and
the electromagnetic induction causes a sound wave to be generated that displaces the diaphragm.