R9 & C7 are forming a low-pass filter, so you could play with C7 as well.
I'd also increase C10 to 220n, C3 to 47n and maybe even breadboard the circuit and swap all the 1µF caps in the signal path for 2µ2. Might get too muddy at that point though.
It's a hit & miss method, whereas somebody who knows what they're doing such as @Chuck D. Bones would just do the math and change only what's necessary.