Using microphone instead of accelerometer is much better but this is just primitive setup and also the delay is ~23ms. Not to mention that it also picks up unrelated sounds. Using dedicated device (esp32) + piezos will be much better. At least I had fun working on this.

Looks cool, what is it supposed to be doing?

First just detect peaks and then I would like to have some sort of drum rudiments trainer 😀 

It won’t be so easy to implement properly using the microphone (also when you consider a possible metronome sound output).

I considered using piezos which are essentially what is every edrum using, I just need to order parts and build it 😀😀

This iOS thing is just really fun exploration without any goals at all.

have you considered some type of strain gauge circuit? i suppose it's hard if you need to retrofit it onto an existing pad