SPK HAT is an M5StickC compatible speaker, integrated PAM8303 amplifier (3w single channel type D power amplifier), High PSRR and differential inputs eliminate noise and rf interference, thus it has the characteristics of simple functions and high audio reproduction.
Only tested with the example. Now finding how to use for my purposes.
Hats are very handful but only one could be attached.
I'll appreciate more hats to came. Good work !