On a KLH Model R7000, how do you get the rear center surround speaker to play?

First of all, Your DVD player must be equip to send the appropiate signal to the reciever. Like for instance it has to have a DTS or a doby digital surround sound decoder as well. In order for you to recieve the center rear speaker a signal. The DVD player must have a coaxial or a optical output on the back of the unit. Coaxial is usually marked in an orange looking mark around the output. You must purchase the correct wire for using this feature. Go to your local Best Buy, Curcuit City or Radio Shack for this wire. The optical is another way of getting your DTS or Doby digital surround sound. The optical wire is a fiber optic cable very flimzy and expensive to buy by the foot. You also can find this cable at your local Best Buy, Curcuit City or Radio Shack for this wire.Note: the rear speaker will only play when the sound is to be played in that format. But I assure you this will fix your problem. Note: the Dolby prologic will play the rear three speaker at the same time when the the movie calls for it to play it but only sounds in that format. I know about this because I used to work in the electronics dept. For 11 years. I hope this fixes your issue and enjoy your unit

On My Teac AG -D7900 receiver, I cant get my Sony subwoofer to come on.( I had to buy a Spkr Cable from Radio Shack with a phono plug on one end for the Teac, while the Sony Sub has the red & black wire clips. On test mode, all speakers work except for the sub. I have turned on the button that shows Sub-Woofer on, but still no sound. I tried all surround sound modes and the Sony sub still makes no sound. I have no Instruction manual, & have no remote. I need help......I don't know what to do next. Can anyone help me?