Systems and methods for improved acousto-haptic speakers

1. A transducer capable of generating acoustic and haptic signals, wherein the haptic signals are transmitted to a user through inertial vibrations, the transducer comprising:

a speaker, including a diaphragm, configured to transform an electrical signal having audio information in a first range of frequencies into an acoustic signal;

a holder attached to a portion of the diaphragm, the holder including an opening positioned above a center region of the diaphragm; and

a mass element attached to the holder above the center region of the diaphragm, the mass element having an opening positioned above the opening of the holder;

wherein the mass of the mass element is selected such that a portion of a resonant frequency range of a combination of at least the speaker and the mass element falls within the first range of frequencies; and

wherein the opening of the mass element and the opening of the holder are positioned such that at least a portion of the acoustic signal passes from the speaker and through the openings.

2. The transducer of claim 1 , further comprising an echo chamber formed adjacent to the diaphragm.

3. The transducer of claim 2 , wherein the diaphragm is substantially rigid and the speaker further comprises a semi-rigid diaphragm attached to a voice coil and the rigid diaphragm, such that the echo chamber is formed in a region enclosed by the semi-rigid diaphragm and the rigid diaphragm.

4. The transducer of claim 3 , wherein the rigid diaphragm is cone-shaped and the semi-rigid diaphragm is substantially hemispherical shaped.

5. The transducer of claim 1 , wherein the mass element is removably attached to the holder.

6. The transducer of claim 1 , wherein the mass element is glued to a center region of the holder.

7. The transducer of claim 1 , wherein the mass element is formed from a rigid material and the mass of the mass element is in the range of about 0.1 g to 20 g.

8. The transducer of claim 1 , wherein the mass element is formed from a metal.

9. The transducer of claim 1 , wherein the mass element is disk-shaped.

10. The transducer of claim 1 , wherein the ratio of the surface area of the top surface of the diaphragm to the surface area of the top surface of the mass element is about 4:1.

11. The transducer of claim 1 , wherein the speaker further includes:

a voice coil attached to the diaphragm for receiving the electrical signal and moving the diaphragm in response to the electrical signal; and

a spider attached to the voice coil for damping oscillations of the voice coil, the diaphragm, and the mass element.

12. The transducer of claim 1 , comprising a plurality of mass elements removably stacked on top of each other.

13. The transducer of claim 1 , further comprising a housing having a cap such that the speaker and the mass element are disposed within the housing.

14. The transducer of claim 13 , wherein the diaphragm is capable of moving up to a maximum height within the housing, and wherein the mass element has a height selected such that when the diaphragm has moved up to the maximum height, the mass element is within the housing and below the cap.

15. The transducer of claim 1 , wherein the speaker is a full-range speaker.

16. The transducer of claim 1 , wherein the portion of the resonant frequency range has frequency ranges from 2 to 800 Hz.

17. The transducer of claim 1 , further comprising a controller connected to the speaker and a source of the electrical signal for splitting the electrical signal and driving the speaker and the mass element with at least one of a signal containing information in audible frequencies and a signal containing information in haptic frequencies.

18. The transducer of claim 17 , wherein the signal contains information in the haptic frequencies and the controller is configured to amplify the signal containing information in the haptic frequencies.

19. A method of generating acoustic and haptic signals from an electrical signal having information within a first range of frequencies, wherein the haptic signals are transmitted to a user through inertial vibrations, comprising:

providing a transducer having:

a speaker, including a diaphragm, configured to transform an electrical signal having audio information in a first range of frequencies into an acoustic signal;

a holder attached to a portion of the diaphragm, the holder including an opening positioned above a center region of the diaphragm;

a mass element attached to the holder above the center region of the diaphragm, the mass element having an opening positioned above the opening of the holder; and

an echo chamber formed adjacent to the diaphragm;

wherein the mass of the mass element is selected such that a portion of a resonant frequency range of a combination of at least the speaker and the mass element falls within the first range of frequencies; and

wherein the opening of the mass element and the opening of the holder are positioned such that at least a portion of the acoustic signal passes from the speaker and through the openings; and

receiving, at the transducer, the electrical signal; and

generating, at the transducer, acoustic signals due to vibration of the diaphragm, and haptic signals due to resonance of the transducer created by movement of the mass element at a frequency within the resonant frequency range, such that the haptic signals are amplified by the echo chamber.

20. The method of claim 19 , wherein the speaker further includes:

a voice coil for receiving the electrical signal; and

a spider connected to the voice coil; and

wherein the method further comprises damping, by the spider, the vibration of the diaphragm and the movement of the mass element.