What are the speaker placements for 7.1 HT setup?

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.