surround set up

[CopperPot]

My receiver doesn't seem to be differentiating between my surrounds. When I play a THX audio test signal or Avia signal both left and right surrounds play even though the test pattern is only being played for one of the two surrounds. I'm using a 5.1 setup, my gear is in my sig. Thanks for any thoughts.

Edit

To further complicate things, if I play test tones from the dvd players internal system it will only play the left and right speakers and nothing comes out of anything else even thoughit shows that a tone is being played. If I play a test tone out of my receiver everything works as it is supposed to. One more thing, my receiver has an auto source selection which picks the proper sound format for the source being inputed. anytime I use it it selects stereo. So, for some reason is my system just playing stereo and my receiver is converting it to a surround format? Does anyone have an idea what is going on here?

Thanks

[MrMcGoo]

Doby Digital Surround EX is a matrixed 6.1 format. The sixth channel is matrixed from the other two surround channels. The matrixed channel drives both surround back speakers with different types of processing depending on how far apart the two back speakers are apart as set in the receiver's setup.

If you want to set the surround back speakers' level independently, the ONLY way to do so is to use the internal test tones from the receiver.

Bill

[CopperPot]

Thanks for the suggestion. The only thing is the problem is there regardless of the selected surround format. And then why does the receier default to stereo when asked to automatically select the surround format?

[CopperPot]

I just fixed my problem. The dvd player was set to PCM and not bitstream. I gather PCM outputs a stereo signal through the optical out whereas the bitstream will send a multi channel signal. I've been listening to some dodgey sound with a pricey receiver for a while.[:$]