My "9.1" setup

[bluseminole]

Though this is in regards to my setup, I thought this belonged here because it could make for good discussion of the theory in general. First, allow me to explain what I mean when I discuss my "9.1 setup".

We all know that no 9.1 content commercially exists. True, discrete 7.1 content is still rare--most movies are still mixed in 5.1 and remixed/processed for 7.1 releases. The only way to get "9.1" is via extrapolation or processing using proprietary algorithms--either ones implemented by a manufacturer for their pre/pro or receiver, or ones such as those offered in Dolby PLIIz. Much like other surround algorithms, however, each one is different, so one 9.1 configuration could vary drastically from another. So in short, what I am discussing is not in fact 9.1 sound, but rather standard 5.1/7.1 sources played back via one center, two main, and six surround speakers, plus one subwoofer.

I don't have a receiver or pre/pro with a 9.1 algorithm. So why and how did I go about creating such a setup? I stumbled on the idea when I discovered I had some extra surround speakers and extra channels of amplification....and ample speaker wire. I knew I couldn't process into 9.1, but then the thought struck me: movie theaters utilize significantly more than 9.1 channels to playback 5.1 sources. And they don't "fake" it. They use arrays--of course, for the purpose of delivering surround effects to the whole auditorium. The secret is effectively channel duplication. Even though the source is only 5.1, the effect of something running the length of the auditorium can be achieved by playing that identical signal through each surround speaker, provided that delay settings are properly calibrated.

I took that idea and implemented it in my home theater room, adjusting the levels to make sure the surrounds didn't dominate the soundfield. The surround L and R speakers are now operating in "pairs", with one set of surround speakers slightly forward of the listening position facing each other face-on across the room, with the other set (the original pair) located to the side and ever-so-slightly behind the listening position facing inward at an angle. The two surround back speakers are located on the back wall.

I have been very pleased with the results--though the accuracy of multichannel music suffers a bit with the sound localization reduced, the effect in movies is very much appreciated. The speakers have disappeared, making the sound much more ambient in nature and not as easily localizeable (is that a word?). In short, the sound is now very much like what is heard in the theaters.

And now at long last, the point of this whole post: I'd like your thoughts on this implementation. What do you think of the idea? I think this is a great topic for discussion--instead of utilizing discrete extra channels, why can't we expand on the same 5.1/7.1 sources by adopting the array mentality used in theaters?