VocalFusion Stereo Dev Kit mic array elements spacing

Technical questions regarding the XTC tools and programming with XMOS.
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sluwindsor1
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VocalFusion Stereo Dev Kit mic array elements spacing

Post by sluwindsor1 »

Hi, I want to buy the device VocalFusion Stereo Dev Kit, and I noticed that it has 4 elements with 33.33mm spacing, I would like to ask why XMOS set up this spacing and this geometry config? If I want to use this kit to capture higher frequency audio signal, should I change the geometry config?

Thank you in advance


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infiniteimprobability
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Post by infiniteimprobability »

Hi, the spacing has been chosen to provide a good compromise between performance and compactness. We originally supported a 100mm spacing but it was physically too big for many products.
All of our certification has been done on the 33mm spacing for linear mic arrays.

You can change the geometry using a #define in the source code. Bear in mind that going below 33mm will reduce the beamformer's ability to improve the SNR.

Regarding capturing higher frequencies (audio frequencies I assume?) the IP works at a fixed 16kHz sample rate so nyquist is 8kHz. The raw microphone PDM->PCM library (lib_mic_array) however can work up to 48kHz sample rate.
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