big screen - two channel system enough for dialog?

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Marakanetz, the link below should give you an idea of the
room and the layout. When the room is my everyday living
room, the couches are along the walls. When I get ready to
watch movies, I move the couches so that they face the
screen. I sit 30 feet from the screen. You can see the
center channel on the floor at the bottom of the screen, I
place it on a platform that raises it two feet off the floor
at movie time. The room is 22 ft wide, 70 ft long and 22
feet high

http://forum.audiogon.com/cgi-bin/fr.pl?vhome&1178590685
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Nice digs.

I'm in the camp of use the center, and surrounds for home theater. Way back in the day, I started with just to channel for movies, and TV. I can't say I didn't enjoy it, I did. Very much back then. Mitches comment about planes flying past is exactly right. There are so many things going on in movies that only having two speakers will limit the experience.

I built a new from the ground up about 6 years ago. (119" screen, and Sony PJ) Regardles of what you do speaker wise, here are a couple things I would suggest.

I assume you will be using a PJ. I ran 3" PVC, 2" would work, from behind my equipment rack, (it's buried in the wall of course) up to where my PJ is mounted. When you make corners, don't use 90 degree elbows. It's better to use 2 45 degree elbows. It makes pulling wire through alot easier. Always pull an extra wire through so if you want to change, or add, you have an easy way to do it. If you use it to pull something new in, pull another extra one through. (since you will be pulling your spare out with the new one)

Even if you go the two channel route, run speaker wires to the back of your room. Just put a blank cover plate on the openings, and forget it's there. The last thing you want is to decide you would like to try the surround later and not have the wires in place. Speaker wire is cheap enough, don't limit your options. I've done some retro installs, and it's a real pain running wires through the attic, or basement, and trying to end up in the walls later. Try to cover any possible future changes now.

There is NO question that a proper center channel speaker will enhance dialog intelligibility. Keep in mind that the center channel is THE primary channel used by the audio guys when mixing for movies. Additionally, it "anchors" the sound to the center for those viewers who are off-axis and not in the sweet-spot.

So, don't cheap-out on the center channel. *Most* mfgrs. nowadays make a center channel that is complementary to their main channel offerings.

I currently run Gallo Reference 3.1s for my main L/R, Gallo Ref. AV Center for my Center, and Gallo Ref. AV for my surrounds. My sound is *superb*, and the 60 inch Mitsu DLP HDTV suits my needs for the moment. But I dream of a 92" Mitsu DLP sometime in my future...

-RW-

No offense, dude, but that room looks like a standing wave nightmare. I would *seriously consider placing some sound damping materials on the side walls near the 1st reflection points. Additionally, some thick, sound damping carpets would go a long ways towards killing the floor to ceiling reflection points.

But, other than that, it is one *hell* of a nice room for a home theater, ya oughta be charging admission. And hey, I need a gig right now, gimme one of those ticket-taker monkey suits with the pillbox hat and I'm yer boy!!

-RW-