Acoustic filters for microphone noise mitigation and transducer venting

1. A playback device comprising:

an earpiece configured to be positioned adjacent a user's ear, the earpiece comprising:

a transducer having a diaphragm configured to face toward the user's ear when the earpiece is positioned adjacent the user's ear;

an outlet vent in fluid communication with the transducer;

a microphone;

a support member having a first opening aligned with the microphone and a second opening aligned with the outlet vent, wherein the support member comprises a first annular member surrounding the transducer; and

an acoustic mesh extending over the first opening and the second opening, wherein the mesh has a substantially uniform acoustic impedance, and wherein the mesh comprises a second annular member positioned over the first annular member.

2. The device of claim 1 , wherein an area of the second opening is at least 50% greater than an area of the first opening.

3. The device of claim 1 , wherein the first and second openings have corresponding first and second areas, wherein the microphone has a desired upstream acoustic impedance based on the first area and the acoustic impedance of the mesh, and wherein the transducer has a desired downstream acoustic impedance based on the second area and the acoustic impedance of the mesh.

4. The device of claim 3 , wherein the mesh has an acoustic impedance of between about 30-150 Rayl SMKS .

5. The device of claim 1 , wherein the mesh is exposed over an outer surface of the device.

6. The device of claim 1 , further comprising an ingress filter disposed between the microphone and the mesh.

7. The device of claim 6 , wherein the ingress filter comprises a foam material.

8. The device of claim 1 , further comprising a third port in the support member aligned with a second microphone, wherein the mesh extends over the third port.

9. The device of claim 1 , wherein the microphone is configured to detect voice input from the user.

10. An earpiece assembly for a playback device, the assembly comprising:

an audio transducer facing in a forward direction;

a housing containing the audio transducer, the housing defining an acoustic volume;

an aperture in fluid communication with the acoustic volume;

a microphone;

a support member comprising a first annular member surrounding the audio transducer, the support member comprising a first port substantially aligned with the microphone and a second port disposed substantially aligned with the aperture; and

an acoustic filter material covering the first port and the second port, the acoustic filter material comprising a second annular member positioned over the first annular member.

11. The assembly of claim 10 , wherein the first port has an opening size that is less than twice an opening size of the second port.

12. The assembly of claim 10 , wherein the acoustic filter material comprises an acoustic mesh.

13. The assembly of claim 10 , wherein the acoustic filter material has a substantially uniform acoustic impedance.

14. The assembly of claim 13 , wherein the acoustic filter material has an acoustic impedance of between about 30-150 Rayl SMKS .

15. A portable playback device comprising:

a speaker having a diaphragm configured to face toward a first direction;

an enclosure defining an acoustic volume disposed behind the diaphragm along a second direction opposite the first direction;

a vent opening in communication with the acoustic volume;

a microphone configured to face toward the second direction;

a first port substantially aligned with the vent opening;

a second port substantially aligned with the microphone; and

an acoustic impedance member extending over the first port and the second port,

wherein the first and second ports have corresponding first and second areas, wherein the transducer has a desired downstream acoustic impedance based on the first area and the acoustic impedance of the acoustic impedance member, and wherein the microphone has a desired upstream acoustic impedance based on the second area and the acoustic impedance of the acoustic impedance member.

16. The device of claim 15 , wherein the acoustic impedance member comprises an acoustic mesh.

17. The device of claim 15 , wherein the acoustic impedance member has a substantially uniform acoustic impedance.

18. The device of claim 15 , further comprising a support member at least partially surrounding the speaker, wherein the first port and the second port are each formed in the support member.

19. The device of claim 15 , wherein the second port has an opening size that is at least 50% of an opening size of the first port.