PWM audio - changing PWM frequency

[palmerr23]

Changing the PWM Audio sample rate on Pico W requires two settings to be changed

In PWMAudio.h: there is an undocumented version of begin( )

 begin(long sampleRate, long PWMfrequency); 

which sets up both the apparent sampleRate (e.g. incoming samples) and the PWMfrequency used to encode them.

I haven't experimented beyond setting them to the same value, but assume that keeping PWMfrequency = n * sampleRate might be a good thing!

Hope this helps someone else save a few hours of frustration!