Help with Subwoofer wiring
I have a new receiver, 2 channel pre-amp and a 7.2 in-wall speaker set. The speakers are installed in the wall and work fine, however I cannot get the subwoofers to work. I am going from the subwoofer 1 and 2 on the receiver (1st photo) via RCA to the Pre-am input 1 and 2 (2nd photo). Then from the pre-amp speaker output to the subwoofer (last photo) via speaker wire. I have tried multiple configurations of hooking up the subwoofer as there are no instructions with the sub (I paid nothing for them, so quality is not expected). Am i supposed to somehow use the 4 terminals to tie in the center speaker (3rd photo). Any assistance would be very appreciated. I tried to give as much info as I can, but please let me know if I need to provide more.