5.1 vs 6.1 with sofa against the wall

[toenail]

I can't recall which of you made the comment on another thread but thank you!!!!!!

I was fiddling around with my HT set up today and for grins disconnected the center rear and ran it in PLII instead of PLIIx. What a huge difference in sound quality for TV/DVD with either 2 channel or 5.1 channel sources. I could never figure out why I wasn't able to get my center channel speaker to deliver crisp dialog/vocals, there always sounded like there was a phase issue or something else muddling up the works. I had checked repeatedly to make sure that all speakers were in phase and had adjusted the Center EQ feature on my Yamaha rx-v450 endlessly to no avail. After ridding myself of the awkwardly mounter rear center (wall/ceiling boundary directly overhead) it was as if someone pulled a sock out of my ears. The improvement was that dramatic. Continuity during left-right pans in the rear channels was also greatly improved, as were back to front transitions. I now can get the sensation of something flying in from directly over head and toward the TV despite the fact that my left and right rears are mounted at just a tick above ear level to either side of the sofa. Previously, overhead sounds seem to come partly from both left and right rears with a hole in the middle. The depth of images in front of the listening position is also greatly improved.

Hope this helps some of you out there. It sure made my day.

[This Guy]

Yep, same thing happened to me, although not as dramtic as yours.

[cam]

I'm with you. I have 11 feet behind my couch and one or two center rear speakers just destroyed my 360 degree experience. For me 5.1 with di-poles on the sides absolutely rocks. Please, no flame wars.

[Woochifer]

Good to hear that your experience coincides with a lot of the advice that I've gotten from others on this and other boards -- and that is to get your 5.1 setup optimized before bothering with 6.1. The imaging is already difficult enough as it is in a 5.1 setup because the surrounds are close to the backwall, and adding another speaker overhead or in some other bizarre position is very unlikely to help the overall experience because it can severely distort the time domain response and the timbre matching because it's so far off-axis from the other surround speakers.

[toenail]

Yeah, I wish I had found out about this sooner. It really does improve the experience.

I've also experimented with rear surround placement recently. Because the right margin of my sofa is only 2 feet from the side/rear wall boundary corner, any position on the sofa other than dead center puts the listener too close to one of the rear surrounds and the center channel output gets colored because of this. Turning the smallish rear surround cubes on their backs and placing them in the 90 degree side/rear corner at just above ear level has improved this some. The indirect and reflected sound gives the sensation of a larger space around the sofa, with effect sounds seeming to come from far to the sides or behind, as opposed to the direct sound which was very obviously originating mere feet from my head. As cam suggested with his comment about di-poles, I think the indirect/reflected sound enhances the experience, at least for those of us with small rooms or awkward sofa placement.

[Geoffcin]

I'm with you. I have 11 feet behind my couch and one or two center rear speakers just destroyed my 360 degree experience. For me 5.1 with di-poles on the sides absolutely rocks. Please, no flame wars.

But, I've had the exact OPPOSITE experience. After adding two in-wall mounted speakers behind my HT the effects have become more cinema like. I'll grant that it's rare for you to notice it directly, it's usually much more subtle, but some movie soundtracks make good use of the rears.

Also; For parties, and just plain casual listening, I set my system for 6 speaker stereo (7 in my case) and it creates a huge "sweet spot" so nobody is too overloaded with the output of just one speaker.

A quick note; With that being said, for critical listening I PREFER 2-channel over any multichannel format I've heard to date.

[Geoffcin]

Good to hear that your experience coincides with a lot of the advice that I've gotten from others on this and other boards -- and that is to get your 5.1 setup optimized before bothering with 6.1. The imaging is already difficult enough as it is in a 5.1 setup because the surrounds are close to the backwall, and adding another speaker overhead or in some other bizarre position is very unlikely to help the overall experience because it can severely distort the time domain response and the timbre matching because it's so far off-axis from the other surround speakers.

A poorly set up 6.1 system is not worth the expense or time to set up. I've always considered overhead speakers an annoance, and I would never reccomend such an instalation unless it's intended use is for MUZAK only.

But;

IMHO a properly set up 7.1 (6.1) system will outperform a 5.1 system. The theaters that I go to all use multiple speaker arrays. It just follows that to duplicate this experience you would try to duplicate their setup as closely as possible. I've found that the rear channel(s) add a fill that provides a sense of "seating depth" that is very cinema like to me.
It also adds to sound effects. I've heard things splash into water behind my head, doors creak, and even planes fly over with startling realism.

[toenail]

2 channel stereo is the only way I listen to music. Properly done, the depth can be amazing.

6 channel stereo IS the bomb for entertaining.

(Offf Topic) I've been toying with the idea of a DIY 3-way speaker utilizing the six channels of amplification, one for each driver in the pair of speakers, just for grins.

[Woochifer]

IMHO a properly set up 7.1 (6.1) system will outperform a 5.1 system. The theaters that I go to all use multiple speaker arrays. It just follows that to duplicate this experience you would try to duplicate their setup as closely as possible. I've found that the rear channel(s) add a fill that provides a sense of "seating depth" that is very cinema like to me.
It also adds to sound effects. I've heard things splash into water behind my head, doors creak, and even planes fly over with startling realism.

The two variables to keep in mind with the quality of the "7.1" reproduction are the room alignment and the soundtrack. If the room is like what toenail describes with the sofa pushed against the backwall, then it's just not worth the effort to bring those extra speakers into the mix because you're talking about a lot of speaker alignments that can introduce time domain and frequency response distortions. Also, the soundtrack is an important variable because if the surrrounds were mixed with minimal separation in the channels, then turning on the back surround channels will collapse the back soundfield into a narrow area. A properly setup 7.1 system CAN sound better than a properly setup 5.1 system IF the set of circumstances are right, but the reality of most rooms and soundtracks is far from ideal.

Another thing to keep in mind with movie theaters is that they use arrays of surround speakers because you're talking about big auditoriums with the majority of the audience sitting in locations not in any kind off "sweet spot." A home theater does not have to worry about conveying a surround effect over an area that large, and can actually convey a level of surround engagement that's not possible in a movie theater if the speaker alignment is done right. "Master and Commander" is an example of how a 5.1 soundtrack for home listening (Terrence thinks that soundtrack was repurposed for the DVD mix) can convey a sense of space and claustrophobia using only five speakers that simply can't be done with large speaker arrays. The kind of encirclement effect that you describe is possible with a 5.1 setup, provided that speakers are timbre matched and they're aligned properly. 7.1 can add to it, but adding the back surrounds can also break up the basic surround imaging if the speakers are just added for sake of adding speakers.

[shaemus]

Nice topic. This is all quite interesting and useful to me as I prepare my basement home theatre/listening room. Glad it came up. Thanks

[Geoffcin]

"Master and Commander" is an example of how a 5.1 soundtrack for home listening

A movie that I couldn't wait to get on DVD. (If I were voting it would get an Academy Award). The first engagement with the Acheron is one of the most visceral scenes this side of beach scene in Saving Private Ryan, and for some strange reason seems even more harrowing even though we're 200 years removed from the time frame. I use it as a referance standard for HT cinema performance, and it's a real test of what you've got. I hook it all up for this one, which includes over 2,000 watts of dedicated sub power, my maggie's as added mains, and the full HT system. The effect is nothing short of being lashed to the mast as the cannon fire rakes the deck, and splinters of wood, lashings, and bodies fly everywhere.

I agree that such an experience is even better in some respects than seeing it in a theater, although I truly feel that the large theater is still the BEST place to see a movie.