What are the speaker placements for 7.1 HT setup?


Dear list,

First and foremost, a great thanks in advance for all
helps in all forms.

I'm in the process of setting up a separate multi channel
audio system for HT. I have acquired the following
equipment for the purpose that fits my budget and taste.

1) Sony DVP-NS999ES DVD player.
2) Mcintosh MX134 pre-amp/processor
3) 3 MC1201 monoblocks.
4) 2 MC602 stereo amp.
5) Monster THX 1000 cables.

I haven't committed any plunder I hope?

I'm in the process of speaker selection for above setup.
Now, the MX134 is capable of 7.1 surround processing, how
many center speakers do I need? What are the correct speaker
placements for 7.1? Do I have a rear center? Is 7.1 better
than 6.1, why?
kee_tan
7.1 means:
2 front speakers, left and right
1 center speaker
2 rear speakers, left and right
2 side speakers
and the .1 is for a sub.

Is it better than 5.1? Depends on the size of the room and the amount of people sitting in the room. I had a 8.1 system and after setting it up I didn't feel that I had gained anything and should have stayed with a 5.1.
As far as placement goes. Start with your most important speakers, the front left and right. Place them just like you would for a 2 channel system. Only you can determine what is the best placement for them in your particular room. Place your center speaker per the speakers recommendation. If you go with the side speakers I would suggest you first place them on the floor directly to your side and start listening, keep moving them back until they sound the best. You will more than likely find that the best placement is where you can see them when you turn your head to the side, in other words slightly back from your sitting position. For the rears, about 110• from the sitting position seems to work for most people. The sides and rears are not critical like the fronts. All they are for are ambiant sounds, and foley effects. The front three speakers are the critical ones, also make sure you set the time delay for your center speaker placement so that there is seemless sonic panning from side to center to side.
Go to Dolby's web site, and they explain the various set-ups for 5.1, 6.1, 7.1, and PLII.
www.dolby.com
Kee_tan,

7.1 will provide a more enveloping surround environment than 5.1. I personally found it significantly better.

A 6.1 speaker array is not a good choice. A single rear speaker is subject to front-to-back reversals and doesn't spread the rear surround information across the rear of the room.

For 7.1, the Dolby web site should show side speakers at plus & minus 90 degrees; i.e., side speakers directly to the side of the listening area (not behind and not in front). Rear speakers should be plus & minus 150 degrees. You may want to experiment with side speaker location if there are multiple rows of seating.

The size of the room per se is not an issue for 7.1, but layout within the room can be. My room is only 13' x 17' x 9.5', but my listening position is such that my rear speakers are behind me. There can be situations when 7.1 is not easy to implement; e.g., if your seating is flush against the back wall and cannot be moved forward to provide some space behind.

Unfortunately, the MX-134 only has DPLII, not DPLIIx, according to the McIntosh web site. You should have DPLIIx or Logic7 to take full advantage of a 7.1 speaker layout. Can you get an MX-135 instead of the MX-134?

Thanks
Bruce
Bruceomega,
My apology, some of your acronyms have eluded my
understanding. I must confess I'm a complete beginner
in HT. What is DLPII and DLPIIx? Are the differences
significant enough to yield my purchase of the MX-134
a plunder? Could be my interpretation, but I'm reading
the matter as MX-134 can only deliver pseudo 7.1?
You'll do well enough with just Dolby Prologic II, go into dolby's web site and if you have any doubt come back here.
..."Go to Dolby's web site, and they explain the various set-ups for 5.1, 6.1, 7.1, and PLII.
www.dolby.com"
Teonyc

This is not bad starting advice, as a good point of reference and suggestions. However, to be true, each setup/room is different, and there's A LOT OF VARIABLES TO CONSIDER! If you don't know what you're doing, you'll be getting hodge-podge sound from all your speakers. Placment is a balance of getting a properly scaled soundtage perspective, and simultaneously getting basically "flat frequency response"(and even response) from all the speakers! Anything else will give you lackluster performance for certain!(what everyone ends up with doing it themes, themselves sadly..I know Basically, as I've been doing this for years for a living)
All the other variables will then need to be considered, like proper toe-in, "aim", and acoustics considerations.
Basically, you're better off(especially since you spent all that money on gear) haveing someone consult you for best. Otherwise, spend years learning and studying, tinkering and tweaking. Bottom line, much more info is needed to recommend for ANY ROOM/SETUP!
Telling someone to stick your speakers at such and such a distance or location in your room is all relative. Also, each speaker is different, and reacts differently in the room. It all must be considered, as the room/setup/acoustics/tweeking/etc, all add up to easily 2/3's of the performance...no joke!
You spent hard on the gear...I suggest considering spending even wiser on the more critical setup/acoustics proceduress if you want anything remotely resembling world class sound!
Yes, equip makers would love you to think that simply buying gear is the answer to world class sound...seasoned audio experts know different. And you'd be amazed at how many (guy's especially) people think they can buy some fancy gear, stick it in a room, and think they have the best sound!...they're wrong....most end up with poor sound, I garantee it, sadly.
As for your gear choices, your gear is fine. You could alwasy tinker with power sources and wires and such. But otherwise that's good stuff. However, like most, the speakers really should be chosen first, as they're the most important in the gear. You then should match gear to match! That's correct normally. But, it's all workable if need be. Good luck
Basically, it is needed to know your room dimmensions, layout, basic acoustical properties, and all the variables in the room, seating locations, etc. All this will make it easier to point out speaker options really.
Kee_tan

My comments are focused on the question of a 5.1 vs 6.1 vs 7.1 speaker system.

My recommendation is to go with a 7.1 speaker system, unless you have a physical layout that just will not support 7.1. If you cannot do 7.1, then I recommend 5.1. I do not recommend 6.1. The general layout for 7.1 speaker placement is a guide. The best implementation in your particular room can vary.

If you do decide to go 7.1, and want to maximize the 7.1 listening experience, then I further recommend you have surround processing that can generate 7.1 outputs from the various input sources available (2.0, 5.1, etc.). This is needed, in my opinion, because:

- There are no 7.1 sources available at the present time

- You do not want to simply duplicate the surround information in the side and rear channels

The two best choices for 7.1 surround processing are Dolby Pro Logic IIx (DPLIIx), which is available on a variety of receivers and PrePros, and Logic 7, which is available only on Lexicon products, some/all Harmon Kardon receivers, and I think a JBL PrePro.

Dolby Pro Logic II (DPLII), the predecessor of DPLIIx, will only generate 5.1 outputs. If you are using a 5.1 speaker system, then DPLII is fine, but if you use a 7.1 speaker system I highly recommend DPLIIx instead.

Thanks
Bruce
The point of my exercise, which has been blessed by the
numerous contributions from you fine gentlemen (of which
I'm most grateful) is the following;

I have contracted the professionals to design and build
a dedicated none commercial theater as an extension to
my existing home. And the contractors have with the aid of
variety of services provided by their networked
consultants at their disposal, constructed a semi-buried
enclosure of the dimension (in the imperial unit) 45 feet
wide, 60 feet long and with a floor that inclines towards
the front resulting in the maximum height of the enclosure at 19 feet and the minimum at 9 feet. The inclination
stretches both direction from the middle, hence leaving two flat levels at the back and in the front. The size of the
front level ground is 45 feet wide, 40 feet deep and 19
feet from ground to ceiling. The size of the rear level is
again 45 feet wide, but 6 feet in lenght and 9 feet in
height. The seating area (the inclination) measures at
14 feet in horizontal length, composing of 3 sitting rows
each accommodating 5 separately reclinable chair. The
complete SLOPE length (not horizontal) of the sitting
area is 17 feet, the height difference between the last
row and the first is about 10 feet. The sitting allevation
from the one before is about 3.3 feet when upright, 1 foot
when fully reclined. The space in between each sitting
row is about 2.8 feet when upright, 1 foot when fully
reclined.

Now the entire conclosure including ceiling and floor is
completely padded with sound proofing material. There is
nothing protruding, except the (rather cumbersom)
crt projector --barco Reality 812-- attached to a sliding
rail, lighting is purely yellow down light completely
hidden in their respective enclosure.

Back to my task at hands, above contruction is completed,
I have on loan (from dealers) few set of speakers, they
are ;

From Wilson Audio
=================
Watt/Puppy full size --4 pairs
No center speaker, the dealer advises me upon the actual
fact that I should have exactly the same speakers all
round given my current theatre design.

From Dyaudio
============
Dynaudio evidence temptation --3 pairs
Dynaudio evidence center --1 pair

From B&W
========
803D --3 pairs
HTM1D --1 pair

My paid professional services are
more than willing to accomodate me while
discharging their duty to explore ALL
possible combinations in its entirety so that
I, as the paying customer could arrive at the
point where to add or remove, to pivot or turn
will result in no gain in sonic performance but
only degradation! But they can't help me to decide
what I like, I have to make that decision my self.
These are mostly music speakers I might ad. Which is fine for some applications, but not a big space like you're using! May I suggest some more high end "active", higher efficiency focused designs better suited to your HT applicastions?
I've sold WATT Puppies and B&W's over the years, and have some experience with Dynaudio. There are simply better MORE EFFECTIVE choices for what you're doing IMO.
You might consider some "ACTIVE" speakers from a company called AVLAR located in Southern CAlifornia. They''re very high end sounding speakers, that are much more dynamic, focused and powerful sounding than the more passive speakers you're mentioning above. They dynamic realism and pressence will be much more cinema like, and yet still remain "audiophile" grade in refinement!...just a suggestion.
The traditional Stereo speakers you're looking at won't DELIVER THE GOODS for a high impact HT. I know this from 20 years and 6 high end audio stores worth of working experience...not to mention I do custom thaters myself, and am a consumate audiophile tweak myself.
Anyway, it's all good...it's just that some choices are much better and effective for your task.
Anyway, good luck-----------------------------------------
I'm with Hbarrel...maybe we could just camp out in the yard or volunteer to run errands for kee tan....Interesting comments from Flrnlamb about speakers...Avlar? hmmmmm
Well I'd be interested to see where you end up putting your speakers, and with which speaker choices you end up with. If you use dirrect radiating speakers all around, localization and distaction from the rears is going to be hard to get away from! If it's not done correctly, you WILL BE continually distracted and "pulled out of the movie" from to much dirrectionality from the rears. This is a common problem with dirrect speakers in back/sides. It's like someone talking non-stop in your ear while you're watching a movie...very tiring, real quick! It's an artform indeed to find the place they sound best in the room, and or end up "EQ'ing" them, plus "making them dissapear properly for the effect.(I know lots of audiophiles think monitors in the rears is more "specific sounding", but this is not how movies were mixed back there, I'm sorry. (it can be done for compromise if careful however).
Another issue for you will be how your speakers sound during your "test spin" with them. I mean, they'll sound INFINITELY DIFFERENT when not placed properly, and with little or no acoustical considerations/treatment in place. Or has this all been done?
good luck
If you look in the back of your MX134 manual, it shows you how to do the the speaker placement.