This is probably a dumb question ... but my receiver, a Yamaha rx-v496, isn't supposed to be a surround receiver. Nowhere in the manual does it say that music (from CDs) will go through all speakers. And yet, when I finally hooked up my new mains and moved the others to the back, I found that when I play music and press the "effects" button on the receiver, music goes through all four speakers and sounds pretty good! Am I missing something? Especially confusing is that the manual, in describing the sound field programs, lists the three for "hi-fi audio sources" (disco, rock concert, and concert hall) and specifically describes the output as 2 channel, yet I'm getting four. Yamaha rx-v496 Yamaha dvd-s510 (used for dvds and cds) Thanks!