I'm in agreement with jbliz...and in the same boat.

Here is a good explanation I found in a current thread over at AVS:

<blockquote id="quote"><font size="1" face="Arial, Verdana, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">the reason for using 2 rear speakers for the mono surround-back channel is because of a phenomenon known as back-to-front reversals: sounds along our centre line are heard equally in both ears, sometimes confusing the brain as to whether the sound is directly in from of us or directly behind us. This is not a problem for a single centre speaker up front (where our hearing acuity is at its best), but it is a problem when using a single speaker directly behind (where our hearing isn’t as good) and sounds can sometimes appear to flip direction. The solution is simple: just use 2 speakers, spread at least 30 degrees away from the centre line. This is why Dolby, DTS and THX all recommend using 2 rear speakers for the mono surround-back channel. Note that it is the only channel where it is recommended that 2 speakers be used.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

http://www.avsforum.com/avs-vb/showt...hreadid=405371

-curtis