I'm making a library. To make Csound files from Haskell.

I'd like to give the user standard filters. With no tunings.

Just input signal, center frequency and resonance. 

You can see it in any synth.

aout lp ain, kcf, kQ

aout hp ain, kcf, kQ

aout bp ain, kcf, kQ

aout br ain, kcf, kQ

But in Csound it's not so easy to guess the right choice.

There are a lot of opcodes and I don't know which way is better.

Possible alternatives are: statevar, svfilter, bqrez, rbjeq

Can you give me an advice.

And then can you propose the reasanoble values for resonance.

I'd like to scale the resonance. So that if user doesn't ventures beyond

the certain value, filter doesn't go crazy. I'd like to normalize the 

input value for resonance.

Anton