Hi, there,
I was working on a near-ultrasound project on MOTO 360 (1st gen.). I programmed MOTO 360 to record sound sweeping 2khz-20khz.
Then I plotted the spectrum graph of recorded audio and found that the frequency fades significantly at 7-8khz. I can never get more than that either using the app I wrote or using some sophisticated wear audio recording apps in google play store.
I checked the ifixit tear-down of MOTO 360 and found that the audio chips are Wolfson Microelectronics WM7121 and WM7132. I don't know why there are two microphones. But I do check the datasheets of those two microphone chips and found that frequency responses are not that bad as what I have encountered here in MOTO 360.
So I can only guess that there is a hard-coded band-pass filter on the audio input to limit the frequency range.??. :confused:
Could anyone help me explain this? It would be greatly appreciated if someone can point out how to record near-ultrasound(say above 16khz) on MOTO 360. :D
Thanks
I was working on a near-ultrasound project on MOTO 360 (1st gen.). I programmed MOTO 360 to record sound sweeping 2khz-20khz.
Then I plotted the spectrum graph of recorded audio and found that the frequency fades significantly at 7-8khz. I can never get more than that either using the app I wrote or using some sophisticated wear audio recording apps in google play store.
I checked the ifixit tear-down of MOTO 360 and found that the audio chips are Wolfson Microelectronics WM7121 and WM7132. I don't know why there are two microphones. But I do check the datasheets of those two microphone chips and found that frequency responses are not that bad as what I have encountered here in MOTO 360.
So I can only guess that there is a hard-coded band-pass filter on the audio input to limit the frequency range.??. :confused:
Could anyone help me explain this? It would be greatly appreciated if someone can point out how to record near-ultrasound(say above 16khz) on MOTO 360. :D
Thanks
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