Bandpass Filter for Sound Character

Apply bandpass filter to shape percussive sounds.

Incorrect (raw noise):

source.connect(gain).connect(ctx.destination);

Correct (filtered noise):

const filter = ctx.createBiquadFilter();
filter.type = "bandpass";
filter.frequency.value = 4000;
filter.Q.value = 3;
source.connect(filter).connect(gain).connect(ctx.destination);