Apple

"The problem of the bit crunch effect was solved doing this :

I stopped to try :

float out = mA0*left[frame] + mA1*left[frame-1] + mA2*left[frame-2] ...

but I did, as in the FilterDemo example :

float outOsc = (pow5(sin(phase)*H1) + pow5(sin(phase*2)*H2) + ...// etc. additive synthesis algorithm; "H" values are the level of each harmonics.

phase += freq;//(if...)

float out = mA0*outOsc + mA1*mX1 + mA2*mX2 - mB1*mY1 - mB2*mY2;

//..."

The problem was that I used twice the variable called "freq". Sorry to have posted for nothing. The solution of the Apple FilterDemo works perfectly inside a SynthNote project. Super!!!