As detailed here (http://www.avsforum.com/avs-vb/showthread.php?t=782601) with pictures, I am turning a detached garage into my home theater.

Right now, the rafters are open, and a few support beams running across.

I have the option of insulating and drywalling so that I retain a kind of cathedral ceiling. Or, I can make it into a more conventional, flat ceiling.

I would really enjoy the extra headroom of the cathedral style, but have heard bad things about how such ceilings behave, acoustically (though I could hang from bass trips at the pinnacle), and the support beams going across would be ugly and limit just how usable that space is (since they could get in the way of line of sight for people on a tall riser, or in the way of the project, etc.).

http://preview.nathanh.photosite.com/~photos/tn/7556071_348.ts1168190320000.jpg

http://preview.nathanh.photosite.com/~photos/tn/7556074_348.ts1168190331000.jpg

What are the pros and cons to retaining the cathedral style, versus making it flat?

I'm certainly not an acoustics expert...but a guess is going to say that the open cathedral idea will be absolutely miserable....at least for a dedicated HT.... I'd go with flat with good insulation, lest you end up with weird resonance issues...

I'm not an accoustics expert either, but I've done a fare amount of reading about accoustics, and I'm pretty sure your cathedral ceiling is the better choice. In either case you'll probably want to apply accoustic treatments. But with the angles of a cathedral ceiling, you've got the benefit of eliminating direct first reflections off the ceiling. Secondly, with the added height of the cathedral, any reflections will be reduced in magnitude by the time they reach your ears. Here's a link that I thought was great. http://www.ethanwiner.com/acoustics.html#bass%20traps
About half way down the page Ethan talks about a peaked ceiling being better than a flat ceiling. Check it out, good info. :D

Craigo

You can hang vertical panels absorb echo. A cathedral ceiling with beams is great, don't flatten it. You can also place absorption on the beams fronts. Were it me, I would hire an experienced sound consultant to help tune the room. Do contact Ethan.

I can certainly see how a cathedral ceiling could be nice -- look at large temples/churches... I guess I worry about it in a HT...while you'll certainly be making it your own....just doesn't....seem....right....to me... ;) lol.

And please note that I didn't mean 'completely' flat in previous. Completely flat is quite possibly the worst thing you could do.

Either way...I'm sure you'll end up with something you're very happy with!

Thanks for the link, Craigo. Here is one excerpt that makes sense (while he acknowledges that some folks don't agree):

"A peaked ceiling is better than a flat ceiling because it avoids the echoes and ringing that occur when the ceiling is parallel to the floor. But a peak creates a focusing effect, much like a parabolic dish, which is less than ideal. For this reason it's a good idea to place absorption or diffusion under the peaked portion, as shown in the photo below."

Given that my predilection is already to keep the ceiling space open, reading that page makes me confident that I can make it work. I currently use limited acoustic treatment in my living room theater. Now that I'm creating a dedicated space, I'll be free to use more, and to put it in the prime locations, such as at the peak.

You've got it. You could make your own accoustical panels wrapped with fabric and then just suspend them below the peak with hooks and cables or chains without too much effort. Looks like you're starting out with a great space for your theater.

Good luck,

Craigo

Thanks, yes, I like the space. As you may note, I have a little challenge with exactly how to configure the space, but hopefully that won't be too tough to sort out.

http://preview.nathanh.photosite.com/~photos/tn/7557117_1024.ts1168193617000.jpg

In particular, it seems too narrow for the back row -- and the back row seems to close to the rear wall -- for the kind of direct radiating surround speakers that I prefer.

I could make it wider, since that dividing wall doesn't exist yet, but I was trying to make it compatible with the existing doors (see details here (http://www.avsforum.com/avs-vb/showthread.php?t=782601) ) for the garage, which have to slide up along the ceiling. That need, however, may need to go by the wayside, and I might need to remove most of the tracks, to open up the possibilities of the space more, in terms of width and how the ceiling / bracing / new wall work.

Any comments or advice about that would be most appreciated! :)