Multiple-use acoustic port
Two or more acoustic transducers share the same acoustic port in a device. The acoustic properties—such as acoustic impedance and frequency response—of the shared acoustic port are matched to each of the two or more acoustic transducers. To accomplish acoustic impedance matching, a separate back volume is provided for each of the acoustic transducers, matched to that transducer. Frequency response matching can be accomplished by the design of the transducer itself, but also by providing an adjacent element in the acoustic system of the transducer. One transducer may serve as an element in the acoustic system of another transducer. Frequency response adjustment of an individual element may also affect acoustic impedance of the entire port-transducer system.
1. An audio device comprising:
a housing defining an internal volume, the housing comprising:
a first transducer having a first acoustic property and a second transducer having a second acoustic property, the first transducer and the second transducer positioned within the internal volume and segregating the internal volume into a common front volume, a first back volume defined in part by the first transducer, and a second back volume defined in part by the second transducer; and
an acoustic port extending through the housing and connecting to the common front volume, the acoustic port having an acoustic property matched to the first acoustic property of the first transducer and to the second acoustic property of the second transducer.
2. The audio device of claim 1 , wherein the acoustic property of the acoustic port, the first acoustic property, and the second acoustic property comprise acoustic impedance.
3. The audio device of claim 2 , wherein the acoustic impedance of the acoustic port, the first acoustic transducer, and the second acoustic transducer is matched to create acoustic resonance.
4. The audio device of claim 1 , wherein the acoustic property of the acoustic port, the first acoustic property, and the second acoustic property comprises frequency response.
5. The audio device of claim 1 , wherein the first acoustic property is partially dependent on a property of the first back volume.
6. The audio device of claim 1 , wherein the second acoustic property is partially dependent on a property of the second back volume.
7. The audio device of claim 1 , wherein the first acoustic property of the first transducer alters the acoustic property of the acoustic port.
8. The audio device of claim 1 , wherein the second acoustic property of the second transducer alters the acoustic property of the acoustic port.
9. A method of tuning an acoustic property of an audio device having a housing defining an internal volume, the housing including a first transducer having a first acoustic property and a second transducer having a second acoustic property, the first transducer and the second transducer positioned within the internal volume so as to segregate the internal volume into a common front volume, a first back volume defined in part by the first transducer, and a second back volume defined in part by the second transducer, and the housing including an acoustic port extending through the housing and connecting to the common front volume, the acoustic port having an acoustic property, the method comprising:
determining the first acoustic property of the first transducer;
determining the second acoustic property of the second transducer;
determining the acoustic property of the acoustic port; and
matching the first acoustic property of the first transducer and the second acoustic property of the second transducer to the acoustic property of the acoustic port.
10. The method of tuning an acoustic property of an audio device of claim 9 , wherein the first acoustic property is partially dependent on a property of the first back volume.
11. The method of tuning an acoustic property of an audio device of claim 10 , wherein the first acoustic property of the first transducer is matched to the acoustic property of the acoustic port by altering the size of the first back volume.
12. The method of tuning an acoustic property of an audio device of claim 10 , wherein the first acoustic property of the first transducer is matched to the acoustic property of the acoustic port by altering the shape of the first back volume.
13. The method of tuning an acoustic property of an audio device of claim 10 , wherein the first acoustic property of the first transducer is matched to the acoustic property of the acoustic port by the inclusion of a first vent in the housing, the first vent extending through the housing and connecting to the first back volume.
14. A sound generating system comprising:
a port having an acoustic property;
a first transducer having a first acoustic property;
a second transducer having a second acoustic property;
a first volume defined in part by the first transducer, the first volume having a property affecting the first acoustic property so that the first acoustic property matches the acoustic property of the port; and
a second volume defined in part by the second transducer, the second volume having a property affecting the second acoustic property so that the second acoustic property matches the acoustic property of the port.
15. The sound generating system of claim 14 , wherein the property affecting the first acoustic property is the size of the first volume.
16. The sound generating system of claim 14 , wherein the property affecting the first acoustic property is the shape of the first volume.
17. The sound generating system of claim 14 , wherein the property affecting the second acoustic property is the size of the second volume.
18. The sound generating system of claim 14 , wherein the property affecting the second acoustic property is the shape of the second volume.
19. The sound generating system of claim 14 , further comprising a third volume defined in part by the port, the first transducer, and the second transducer.
20. The sound generating system of claim 19 , wherein the first acoustic property affects the second acoustic property via the third volume.
21. The sound generating system of claim 19 , wherein the acoustic property of the port affects the first acoustic property via the third volume.