New theater(dedicated) in the works. I have structured wiring in the home and my CEDIA installer wired the HT for 10:1 just in case!
Currently planning on 5:1 surround with M&K 150's and tripole surrounds. Got (2) LFM-1's also. QUESTION: since CLEAR dialogue is the most imp. aspect of my HT, should I consider the sixth channel speaker(ie. rear center surround)? Would I gain that much ?
Thanks in advance.

That center rear channel is an effects channel and won't really have anything to do with dialogue, unless the effect is to have someone behind you. Still, it wouldn't be there for very long.

It does add to the surround experience plus more and more movies are being offered in that format. If you can afford it, I'd do it. If you can't, you'll get along fine without it.

the 6th channel will add very little over two good 4th and 5th channel speakers. why wouldnt you go for 7.1 instead of 6.1 in the first place though? not that 7.1 is much better than 6.1, but what are you going to do with/get 1 speaker? if you upgrade in the future you dont want one oddball. 7.1 is for larger rooms, because it gives a broader sound stage, 6.1 does this to an extent but is more for the very rear sounds. tripole/dipoles achieve that sound very well anyway, so the point is moot. if you were going with standard bookshelfs for the rears, then you would see more of a difference, but with tripoles, its a waste of money.

------------------
This post has been brought to you by curegeorg, thanks for reading.

A rather small HT @ 13'x17'.
All matching speakers within (M&K). thanks for the response(s).I'm thinking 7.1 will be overkill for a smallish room.(?)
Been building this friggin house for nigh on 13 months now- with my 950/770 and (2) LFM-1(s) STILL in the boxes!

i doubt 6.1 will offer much improvement, but "the more the merrier" i guess, and at least you wont have to second guess yourself. i say that because you seem to be for 6.1, just looking for some reason not to do it.

its only money, who cares?

good luck.

------------------
This post has been brought to you by curegeorg, thanks for reading.

A single rear speaker behind your head is a bad idea because it can cause back-to-front reversals. It's a well researched and documented psychoacoustic phenomenon where sounds along the centre line can sometimes appear to reverse direction momentarily. Sounds along the centre line are heard equally in both ears, and it can sometimes take our ear/brain mechanism a moment to figure out whether the sound is in front of us or behind. This is not a problem with a single centre speaker directly in front of us, where our hearing is at its absolute best and we have visual cues. However, it can be a problem with a single speaker directly behind, where our hearing is not so hot.

The solution is as simple as it gets: simply use two rear speakers, placed well away (at least 30 degrees) from the centre line. This is one of the primary reasons why Dolby and DTS and THX all recommend using two rear speakers, even for the mono surround-back channel of EX/ES soundtracks. Note that this is the only channel where it is recommended that two speakers be used for playback.

If you check the Dolby, DTS and THX websites you'll notice that none of those companies refer to the third surround channel as the centre surround or centre rear or 'centre' anything; instead calling it the surround-back channel. More than just semantics, the contents of this channel are supposed to image from behind you in general, not specifically from the centre of the back wall. Another good reason to use two rear speaker (7.1 instead of 6.1).

Like you, I too feel that dialog intelligibility is most important when watching a movie. The last thing you want is for surround-back information to image directly in front of you, right where the dialog is. Going beyond a 5.1-speaker set-up has three immediately noticeable benefits. Better envelopment; four surround speakers wrap around you better that two can. More distinct localization; you'll clearly hear surround effects to your right, to your left and behind you. And greater stability in the surround field; no matter where you're sitting on the couch, sounds intended to come from behind you always appear to come from there - not some side-ish, rear-ish direction. No magic involved, simply a pair of speakers physically located behind you (makes it hard for those sounds to come from any other direction).

All of the above is difficult, if not impossible, to do with only two surround speakers, where you're relying much more on phantom imaging (inherently unstable, moving when you move). The best surround speakers can't be in two places at once. Size doesn't matter. Wait, let me rephrase that: room size is not as important as where the listening area is. For example: you may have a very large room but, if the couch is against the back wall, you won't be able to properly set up a 7.1 system because there will be no room behind you for the rear speakers. If your seating area is away from the back wall, then you have the makings for a good 7.1 layout.

Sounds along the side walls should come from your sides, sounds from the back wall you should image behind you. This directionality should remain consistent, whether you're watching a movie in a large auditorium or a cozy living room. Your 17 foot long home theatre is plenty big to accomodate a 7.1-speaker set-up and enjoy its benefits.

Good Luck,
Sanjay

Excellent summary, Sanjay. I originally set up a 6.1 speaker system in an 11'x19' space with matching dipoles on all three surrounds, but I've currently got a 7.1 speaker system with dipoles on the surround backs and bookshelf speakers on the side surrounds - which I definitely prefer. In both cases, the listening position was well off the back wall, as Sanjay points out is important to making it really work. The rear surrounds do make a difference. If your layout is conducive to rear surrounds, it would be worthwhile - and with the amp channels and speaker wiring already in place (which I'm assuming is the case since you mentioned that the installer wired it up for 10.1), the bulk of the work is already done.

------------------
gonk -- 950 Review | LFM-1 Review | Pre/Pro Comparison Chart | Saloon Links

sanjay did a good job of explicitly saying why 6.1 sucks and 7.1 is preferred, and i agree with what he said. hopefully the different approaches shed some more light, err i mean sound on the subject.

like i stated, 7.1 is typically better with the 6th and 7th channels being direct radiating bookshelfs (or towers if you are up to it) and the sides (5th and 4th channels) being multipolar.

------------------
This post has been brought to you by curegeorg, thanks for reading.

[This message has been edited by curegeorg (edited September 22, 2004).]

You do?!? But a few posts ago you said "not that 7.1 is much better than 6.1". In fact, the main reason I posted in this thread is to counter your comment above as well as your claim that "7.1 is for larger rooms". I wanted to make sure MurphyMan knew that 7.1 IS much better than 6.1 (and why) and that even small rooms can benefit from 7.1 set-ups.

Anyway, I'm glad you agree with my comments. Just a little surprised I guess.

Best,
Sanjay

You better read Gonk's post again. He said just the opposite. He prefers dipoles on the rear and direct radiators on the sides. Then again, maybe Gonk just mis-stated his setup.


------------------
Tekdredger

[This message has been edited by tekdredger (edited September 21, 2004).]

[This message has been edited by tekdredger (edited September 21, 2004).]