The capacitors at C11 and C14 set an audio filter. If you prefer the unfiltered sound, simply remove those two capacitors (don’t bridge the pins or put anything in their place). Alternatively, if you’d like more filtering, add 0603 capacitors that are higher than the current value of 75pF:
As always with audio, some people might say “they sound the same”, so here’s a chart that might better demonstrate what’s happening. The higher the capacitor value, the earlier the roll off begins:
