Can someone refer me to a site that shows how to make an active crossover. I want to connect my sub to my Main and Sub Preouts (Main preouts put out quite a bit more bass for some reason) However the sub seems to put out quite a bit of distortion when connected to the main preouts. With subamp at 50z. I think this is because the 12db/octave filter doesn't rolloff fast enough. I would like to make an active filter to: Combine the three preouts Put signal through lowpass xover at 60hz at 24db/oct Put signal out to one rca.