7.1 vs 5.1


Finally added the Aerial SR-3's to my home theater and have achieved 5.0 at this point. I built the room for 7.1 or 7.2 capability. Any comments from those that have made the jump. Is the experience of a rear pair of speakers significant? (BTW, the room is 32'x15'x8.5' with the side speakers at about the 20' mark.)
quicke
I've only had 5.1, though my intention is to do 7.1 if/when the room gets redone. However, my real answer to your question, for what it's worth, is I think it depends on how you derive the 7.1. Since it's not encoded discreetly, 7.1 has to be derived, and something like the Lexicon L7 decoding is supposed to be superb. My guess is that, like many good things in audio, you'll only notice a significant improvement if you set things up real well. I don't know what that is, not having done it myself (yet), but if you read Lexicon's setup description, assessed whether you could do it "right" in your room, and then did so if you decided you could, my guess would be that you'd have a real step up in performance.
When I expanded from 5.1 to 7.1, I found a significant improvement in surround envelopment. The improvement for me was such that I never want to go back to 5.1. My room is relatively small, about 12' x 17' x 10'.

I strongly recommend you track down a properly set up 7.1 system (unfortunately not always easy to find), and compare listening in 5.1 versus 7.1.

FYI, there are some very articulate threads in www.avsforum.com, especially by sdurani (sanjay) explaining the limitations of 5.1 versus 7.1 for surround envelopment. I think those threads would be very helpful, although a firsthand listening experience is the best way for you to evaluate this.

I also wholeheartedly concur with Kthomas' comments on making sure you have a capability to generate a quality 7.1 listening environment, as there are no 7.1 sources to my knowledge. I use Logic 7 in a Lexicon MC-12 and it is excellent. I listen to everything in 7.1 independent of the source. From what I have read, an alternative now available is DPLIIx.

Thanks
Bruce
I don't think it is worth if you only listen to DVD video(source resolution not good enough). I listen mostly to DVD-A and SACD and only in 7.1 (Lexicon MC12). It is very important to have very similar speakers and amps all around. My system consists of Revel Studios, driven by Rowland Model 9's through ML #32 in SSP mode, Revel Voice, driven by ML 436, 4 x Revel embraces driven by ML 432's, and Revel Sub 30. Worth the investment!
mariusc,

Are you saying you don't use Logic 7 on DVD-V sources, or you don't hear much difference between 5.1 and 7.1 when listening to DVD-V?

In my own experience, I find 7.1, using Logic 7, provides much greater surround envelopment than 5.1 with DVD-V sources.

Thanks
Bruce
With direct-radiating or bipole surrounds, 7.1 yields a quantum improvement in immersion over 5.1. Not as noticeable as adding surrounds to 2 speakers which can provide a near 180 degree sound field but still significant.

The added surround back channel on THX-EX/DTS-ES tracks can also be used to good effect although few films do.