Unsolved Aliasing/decimation filtering audio

[andrea]

I am using arduino, and I would like to set my sampling rate to 16khz as it is more stable with the application and I am only interested in low frequencies.

Do I need to be concerned with aliasing at all, or is this handled at a lower level?

Thanks

[CamilaSouza]

Hello, @andrea

Two of the Spresense analog channels are high speed with anti-aliasing pins - High Performance A/D Converter (HPADC): A4 and A5.

Some useful links:
https://developer.sony.com/develop/spresense/docs/hw_docs_en.html#_analog_to_digital_converter
https://developer.sony.com/develop/spresense/docs/circuitpython_tutorials_en.html#_circuitpython_analog_in

[andrea]

@CamilaSouza Apologies for not specifying, I am using digital microphones with PDM interface. How is it then?

[CamilaSouza]

Hello, @andrea
I haven't found specific mentions to aliasing filters in the documentation, but you should be able to use the 16kHz sampling rate without any problems using the DSP binary for encoding.

This post could be very useful to your use case. Please take a look at it for further details.
https://forum.developer.sony.com/topic/614/audio-recorder-example-not-working-under-8000-and-16000-sample-rate