Posted in another thread with no response. Maybe someone here can help. Have a Denon 4802 set up with 6.1 speakers. Looking to add a sub to the rear. The amp has 2 sets of pre-outs for the rear. Does the speaker size (in setup) dictate what info gets sent to the pre-outs? Can I use a Y adapter to combine the left surround with left rear surround and Y on the right to feed left and right to the sub? Is it possible this setup could damage my receiver?