my brother has a 2 channel amp. he has 3 subs in his car and this is what he did. he ran 1 channel to each subwoofer. then took the bridged channel.(the positive from one and the negative from the 2 channels) and ran it to the 3ed sub. it seems to me this would be bad. it sounds good and his amp works fine so i dont know. any1 suggest anything?