[OBF]

This question could also apply to a 7.1 or 7.2 or whatever fancy setup a person might be interested in, but even a more basic 5.1 multi-channel setup seems to be very problematic for me and I'm wondering if others have dealt with the same issue.....or if HT requires center seating only.

My dedicated "media" room is a 15 x 22 rectangle with mains on the short wall.  I have a 3 person couch in the near ideal position and a couple small chairs to the front/sides of the couch.  However, when I have larger groups of people over for movies/sporting events/parties that amount of seating isn't enough, so at the back of the room is another couch to one side and then I have a foosball table to the other side.  Based on the location of the doors, window, and projector screen, the basic layout is set. 

So.....if I was to do 7.1 like I would prefer, the back seating would be behind the "side" speakers and the rear surrounds would be either aimed right at your ear or above by necessity.  This doesn't seem viable.  Even 5.1 would either have the back seats behind the speakers or directly in your ear.  So my question is, is the basic reality that you can't have "back" seating in a HT, or perhaps it could be dealt with by only using the multichannel for 1-3 people and then when I'm entertaining or having friends over for a football game, switch to 2 channel and shut the back speakers off?  Maybe some sort of omnidirectional speakers for surrounds at the wall/cealing corner above the back row and just be happy with 5.1?

[mcgsxr]

I cannot speak to the 7.1 answer in particular, but could you switch it up to an All Channel Stereo setting, and thus relieve the need for a sweet spot?

I realize that this would a deterioration for the best seats for sure, but would likely more evenly distribute the sound some.

Just an idea.

[OBF]

Hmmm.....well, currently I have a 2 channel stereo system so I'm just thinking of options if I was to go MC.  I don't think it would be necessary to add speakers if I was going to stick with stereo.  I think stereo is fine for movies, but I do sometimes wonder what I'm missing......

[Wayner]

Sony, who is the driving force for DVD audio, recommends all 5.1 speakers be located on an equal radius from the central listener position, with the front left and right being almost an equilateral triangle. The 2 rear channels ideal spot is about 15 degrees behind your sides. In otherwords, the rear surrounds are not suppose to be way behind you, but slightly behind your ears. If your not designing a listening room from scratch, this might be a little tough to accomplish.

Wayner

[ted_b]

Yes, you've hit on a major problem with home theater surround, the room!   The cinema has a big advantage (pun intended) because each individual is never so close to one set of speakers that it drowns out the others, but in your size room (same is mine, 15.25' x 22.75' x 10) anyone but the front center row folks have the potential to get blasted from surrounds.  (Note: Dipoles or Bipoles in the 7.1 side and rear surround positions help somewhat, in that they create a cloud of sound, which is ok for movies and bullet-whizzing or thunderstorm foley effects.)  It is even more difficult for hi-rez surround music (which requires discrete direct-radiating speakers), which I've come to the conclusion is not much more than a sweetspot of 1-3 people clustered toward the equidistant middle.  That's OK though, it's good to be king.     I've invested a boatload into my dedicated 5.1 hirez surround setup; less so for my dedicated side and rear dipole movie surrounds.

So...this is what I do:
I've created two distinct surround setups (along with 2 channel of course, 70% of my listening) that are 5.1 hirez music surround (me and maybe one other sitting directly behind me), and 7.1 movie surrounds that allow for a lot more margin of error as people sit off axis and/or deeper into the room.  The direct radiating fronts typically wield better control of the soundstage even if you're sitting near a dipole rear surround, for example, so you still get the panning effects, etc and are not blown out of the world the movie is trying to create.

Here's a drawing of it, in a somewhat up-to-date setup.  The dipoles, marked with red arrows, have a null at their center so if you are right on them, as the front row is, they are not blasting.  And if you are off them, you are hearing them and at least 1-2 others, likely the fronts:


Here's the front view



and rear view (step/riser isn't built yet .  The new music surrounds aren't visible in this pic cuz they were just delivered by Bob Smith (SP Tech) on Friday.  Rear sofa is placed there mostly to mimic final seating)



Net/net, it CAN be done, at home, with dipoles but you have less than perfect music surround capability.  If most of your surround needs are movies, you will do well with dipoles and 7.1 over 5.1 (cuz the envelopment and diffusion of sound across more people).  If you need to stay 5.1 then that's ok too, as long as you bring them back from the 90 degree sides to more like 110 degree (called the ITU setup in music surround world).  Stay with dipoles, though, or you'll still be blasting Aunt Nellie as she gets the corner chair.  Good luck.

[OBF]

Wayner, that's exactly what's irritating....this IS basically a dedicated listening room except I need it to be multi functional and it just isn't possible to jam 7-8 people into a center sweet spot.  You'd need 2-3 rows of seating close together like in a theater and that is not good for socializing.  This is an oversized 3rd garage stall that I designed to be my listening/movie room, but that could easily be converted back to garage space by a potential future owner.  Apparently, what I REALLY needed was a 4 car so I could have a 2ch party room and a 7.1ch dedicated HT.  Maybe next time 

Ted,

That is very helpful.  I'll have to digest more of that later as I'm leaving work soon.  Your layout is quite similar to mine except for my back wall being shared between seating and a foos table.  I'm also planning to do a 2' riser for just the seating portion so it will look down over the table and so I can keep my screen lower.  Swap your front 3 chairs for a dual reclining couch and it's the same idea.  Your graphic + actual pics is very helpful in understanding.  So one question for now:  do you use the same processor to handle 5.1 high rez and 7.1 movie duty and then a different 2ch pre, or do you have a nice pre/pro that is good enough to handle all 3 scenarios?  And you're using diopoles for all 4 surround/rear speakers just as a matter of compromise?

[ted_b]

OBF,
I'm using dipoles for the 7.1 movie surrounds because they do the null/envelopment thing that you probably could use too.  They don't blast the nearby seat straight on, they diffuse the soundfield for those somewhat nearby, and they produce a cloud of sound, effective for rain/bullets/speeder bikes.  On the exact opposite side of that coin we have my music surrounds, a set of identical drivers to the fronts, for direct radiating musical imaging in a 5.1 setup.

I have a very high quality dedicated stereo tubed preamp (Modwright LS/PS 36.5) that has an HT bypass capability, an absolute must if you want 2 channel greatness, and yet use the same connections and a separate signal path for front l/r channel surround.  I use the same processor for 5.1 music and 7.1 movies.  The processor has dual output connections (XLR and RCA) for each channel, so I use the XLR surround outputs to my music surround stereo amp (which drives the 2 SP Tech Continuum AD's), and RCA surround and RCA rear outputs to my movie multichannel amp (which drives the 4 Alon dipoles).  The two surround amps are never on at the same time.  My center has its own amp, as do the front mains, of course.