I am placing a Speaker pHAT/Raspberry Pi Zero in a 70mm X130mm X 45mm deep plastic enclosure (with grille cloth cutout for the speaker). The standoffs will position the front face of the pHAT board ~ 3-4mm from the grill cloth). For best sound quality, which is best:
- Sound-absorbing material (e.g. foam) at back of enclosure (i.e. behind underside of RPi0)?
- Nothing at back of enclosure?
- Other? _____________________________________________________________