Hey there, I'm currently trying to create an EQ unit with a set of band-pass filters, and audio adder and an audio subtractor, so that the bp~ signal mixed with the unaltered signal will produce a boost at the set frequency through the adder, and cut through the subtractor. While the adder works fine, the subtractor seems to produce just the bp~ signal without the main one, no matter which way I link the inputs. Is there something vital I'm missing here?

http://www.pdpatchrepo.info/hurleur/Readsf.pd

I'd try sticking in some values for the BP filter for the center frequency and Q

I think you're getting weird resonances as a result of the phase offset generated by the filter. Stacking [bp~] like that only makes the phase worse, and I don't think you really need to since you can adjust the bandwidth with the Q inlet. Also, you should use [vcf~] instead of [bp~] for this. It seems to have a better phase response for adding and subtracting from the original signal.