Room design - home theater

Your best bet is to build the structure as rigid as possible at the most cost effective way and put the money into proper room treatment.

A conventional room with flat ceiling can be properly acoustically modeled which when built with the right dimensions can be modeled to have the fewest and most benign null points in the room, then with the right types and placement of treatments you can get a good sounding room.

With the current idea of 20% use for video events you likely won't be going to a projector... BUT JIC... the level ceiling approach does entertain some further consideration.

Things change, right? I know they do with me.

i saw some time back a calculator for room sizes which inherently reduce or eliminate nodes.... not sure if I saved that link or not... but it also mentions the actual height of the room as the integral dimension for configuring it's W & L.

it went on to inform that the actual physical dimensions, all 3 of them, determined much of what would be needed for room acoustical correction, with the height being the fundamental property. I believe it also had a calculator one could use that would theoretically disclose nodes for each set of dimensions.

I'm sure a Google search for things like the "perfect audio room size" or such ought to provide you better insights.

If I find the link in my favs I'll post it here later.

BTW my room is about identical to yours and mine has a gently sloped ceiling risinig to 8.6 ft. or so, and my screen and squeakers are on the short wall. Pro is about 10-11 ft away from the screen on the ceiling... and all is well image wise despite the fact I've a DLP that doesn't have the flexibility of many LCD pros in terms of placement and image throw... just keystone (up & down).

there are other considerations too about what could be built into the walls... or ceiling. Depending on how deeply you want to dive into that rabbit hole. One can spend a lot of time and $$$ just in the construction. I even saw braces that went between the studs that you could 'tune' the room with, after all was completed, as it left exposed a set screw device you could insert a torque wrench into!!

ONly thing I'd submit to do in the construction that I wish i had done was place one or two more outlets additionally for ea dedicated ckt you run.... as you never know... and arrange them for specific gear placement. Allowing for symetry in running power cables to the gear, depending on how you'll set your's up. If on the side wall that won't be as critical as setting mono blocks beside each speaker can be.

Placing the sub or subs too …. They’ll need power, right? Until you get set up and shove ‘em around, you simply aren’t going to know just where to plug them in. so having a couple extra even if they go unused, outlets is a very handy thing.

Then too is the thoughts on running the interconnect & or speaker cabling... in wall? In conduit in wall? under the flooring?

Under a rug should not be your first choice now.

Having less lengthy cabling exposed to the eye, but still able to change it out easily sure does add to the neato & polished esthetic of the finished product. That's real important BTW. As nice as can be a dedicated room audibly, cables running about and all over the floor is a subtractive thing.

My upcoming plan is to set monos by each main speaker with short spkr cable run exposed, and place power outlets in the floor adjacent to the amps. That ded ckt will be supplied by the ‘soup du jour’ plc. I can live with that.

Lighting is key too for wow factorization.

Low voltage? Standard? Dimmer? Recessed? Baby spots? Where? How many? Incandescent & partially directional recessed is THE way to go IMO.

I wound up doing std track lighting using a lutron remote dimmer. 8 50w bulbs covers the room well and all are about 18 – 24 in. off each wall. Albeit mine are not placement sensitive as I can relocate them… but don’t anymore.

Lastly, if you’ve the desire or concerns for addressing power line issues, providing a separate service for that room using a iso conditioning transformer, now would be the time to do it. Isolating your dedicated room electrically as well as sonically via in wall insulation upgrades, will be perhaps the most beneficial things you can do for both present and forthcoming equipment and your listening pleasure.

Bottom line in these things is simple…. What you can live with vs what it’ll cost to do it better, always is a good question that I ask myself…. As I’m not in the ‘cost no object’ camp.

Very good luck to you and enjoy!

Hi guys, thanks for all the responses..

With music is the main focus, we are not going to have a projector. After back-and-forth with the architect, cuffered or tray ceiling will be the choice. with 8 feet at the wall and 9 feet center (this design makes my wife happy). With the ceiling done, now we need to work on drywall (special for HT and music?), insulations, cables, dedicated line, lighting, etc.. I didn't think about these details until I read your comments, especially Blindjim.

Well, I will take it slow and make it right. Thanks again.

You may want to order and read a copy of the book Premium Home Theater, design and construction. This book is written by Earl Geddes and is available on his website gedlee.com. it is not cheap about $45 I believe but it has a lot of useful info that will be helpful to you.

if you're building from scratch here, you might as well do it the right way. If music, you'll do well with the coffered 9' ceiling. I would also NOT do exactly 14' x 21'. You will get much much better sonics if you add 6%-7% difference between multiple dimmensions. (i.e, add 6% to either the 14' dimmension, or 6% to the 21', but not both).
Also, a HUGE benefit of your coffered ceiling is that you can put a massive bass absorber in the ceiling/attic above! In a room of that size - if it's a issolated, sealed in space- you can be assured that you will need to do something with all that excess bass energy. Building a bass trap in the attic space above -accessed from within the inner spaces of the coffering (spaces covered with acoustic transparent fabric- transparent to space above) is an ideal way to balance out the RT time in the room, and make for a supper fast, dynamic, solid bass response from the system. The norm is a slow, fat, overly warm bass sound from sytems, with too much bass overhang covering the sound - especially in smaller acoustic spaces such as this. (yes, 21'x14' is still a small acoustic space).
Regardless, keep the hard dimmensions of the room at multiples that are at least 5%,6%,7% different than each other dimmension, to keep bass modes from piling up and compounding in the room. Results will be a better foundation.
There is of course tons more to the acoustics of your space, building techniques, etc. But I hope this coveres the issues you mentioned.