Is it possible to monitor input levels in order to set the DMIC gains?

Question

So I've got the Wolfson card set-up and recording is successful. However it is a little different from a recording studio . When setting the gain levels I feel blind. Is there a way to monitor input signal to ensure there will be no clipping/to ensure there is adequate signal? If not how does one decide on gain levels without opening a test recording up in a DAW to view the waveform?

Second question, the 'input volume' when setting up the recording by this guide Wolfson Audio Card - Command Line recording Is a little confusing. What exactly does that control? Shouldn't the recording be made at 0dB and the DMIC gain used to alter volume?

Any guidance or tips would be much appreciated.

Kind regards, Ollie

Former Member · Answer

If you put -vv (that's two v's) onto the command line for arecord, it will give you level meters. The "input volume" in his script controls the gain of one of the four inputs on AIF1TX1, the Wolfson card's interface to the RPi. That gain control can be adjusted between -32 dB and +16dB in 1 dB steps, using numerical values 0-48. He's setting the gain to the numerical value 32, which is 0 dB. -- Ragnar