How about this? Is this only responding to an input of 20 through 50 and adjusting the opacity from 0 to 60?
opacityController = thisComp.layer("Soundkey 01").effect("Sound Keys")("Output 1");
if ((opacityController >20) && (opacityController < 50)) {
easeIn(opacityController, 20, 60, 0, 60);
easeOut(opacityController, 20,60,60,0);
}else{ 0; }
Motion Designer / DJ / Father
http://www.lukaszpason.com
http://www.krop.com/lukasz