# bass distortion

Started by November 17, 2004
```hello

i'm trying to implement a distortion for guitar with waveshapes like:
f(x) = ((1+A)*x)/(1+A*fabs(x))
or
f(x) = x*x*x/3;

the problem i'm having is that, for low frequencies (bass), the sound
is strange... it tends too much for treble (not exactly treble, but
more likely a medium frequency) and doesn't sound good... at the same
time, I can't cut those frequencies because, since it isn't "too
treble", I'd lose interesting frequencies when playing other strings

anyone has some suggestion on how to "fix" that?

Thanks in advance and sorry my English
```
```Hi Luis,

these two types of distortion will create only odd harmonics which
might or might not be what you want. Try using a distortion that
creates odd *and* even harmonics for comparison, maybe this is more to

Also, if you use Chebychev polynomials as your nonlinear transfer
function you can create exactly those harmonics that you want. For
example, the second-order Cheby poly f(x) = 2x^2-1 creates the second
harmonic, the third-order poly f(x) = 4x^3-3x the third, the
fourth-order poly f(x) = 8x^4-8x^2+1 the fourth and so on. That way you
have better control over both the bandwidth (important for aliasing
considerations) and the harmonic content (important for the sound) of