I'm working on a dedicated home theater with a very low ceiling. I'll be lucky to get a full 7' and that's not counting one or two places with duct work that will have to be enclosed. The room is about 20' long by 14' wide. I've always liked the idea of a perf screen, especially in this situation but I'm looking for some feedback. So the question is; Is it really worth spending twice the $$ on the AT screen for the improved center channel location? I'm not too concerned with the "hidden" aspect of things. he wants full range floor standing fronts, if possible. the budget is OK but nowhere near the "sky is the limit" that many of you seem to enjoy.
I come from the school of thought where I won't use a center channel at all if the location is going to be way off center.
This is one of those projects where basic 3D modeling would be helpful to get a good picture of what the end result is going to look like.

I just did a job with a perf screen and the customer LOVED the outcome. I have always been leary of using per screens with fixed pixel projectors but I didn't notice any moire whatsoever, and I looked hard to find it. I like placing all three front speakers behind the screen when using a larger screen. If I were to build a theater in my house I would use a perf screen. On another note I have sold one of those new non perf AT screens but haven't seen it (on of our cash and carry theater customers) I do have an open invitation to see it though and I think I'm going to take him up on that offer after the Holiday busy season. I'll post what I think then if I go.

I think you've forgotten a number of important details...

From your discussion of the room, I'll assume the wall on which the screen will be mounted is 14' wide. Is this correct?

What projector are you planning on using? (Depending on projector, perf may cause some unusual effects.)

One row or multiple rows of seating? Distance to closest and farthest seat from screen? (This determines if perf will be very visible.)

Screen size and aspect ratio? (How much space might be above and below screen for center channel speaker.)

I think placing the center below the screen can work almost as well as above. Are you bringing this up because you don't think you have the space to mount a center above the screen?

It's true that there is a lot more to this than "to perf or not to perf". I'm just starting to lay it all out now.
I need seating for 8-12 so there will be at least two rows of seating, which in my mind kills a center channel below the screen.

I was planning on the Infocus 7210. With the ceiling height so low I expect the projector will have to go at the back of the room so the screen size is probably going to be dictated by how long we make the room. Any sort of raised seating is going to be pretty painful for tall people.

Right now it's an open basement but, as ususall, the HVAC is right in the middle of everything.

An AT screen is probably the best solution for your application. I'm not sure which "perf" screen you are looking at. Vutec makes the most reasonable cost solution, Screen Research is probably the best but priciest, Stewart is not as expensive but should be used with EQ and ideally needs a little space behind the speakers. With EQ the Stewart is the priciest.

Another option depending on budget might be something like the Da-Lite Acoustical Imager which has the speakers built into the frame. The speakers aren't as good as most floor standers but just an option. But decent for the price.

The 7210 might not be the best choice for a low ceiling unless you plan on keystoning it. If there is obstructions in the light path (HVAC, Beams, etc.) the 7210 has quite an offset and with 7' or less ceilings the throw and offset might make a screen that starts near the floor. And depending on the seating the seating might be in the way as well.

I'm not too fond of speakers below the screen especially for multiple rows and if the screen is going to be very low in the room because the center would have to be on the floor or very close to it. Speakers built into a soffit above the screen angled at the listeners might be a better option.

Hope this helps.

Bob

After using the Screen Research, I will never sell a perf screen again. No possibility of moire and truely color neutral. One of the big problems of re-eqing speakers behind a perf screen is how hard you have to drive the tweeter. I have also done perf screens without seeing a moire, but in other houses with almost exact same setup (same projector, screen size, etc) see moire.

My .02, if the guy has the money and is willing to spend it, use the Screen Research. You'll both be happy with the results.

Looking at the projector:
If you do a 100" 16:9 screen
Screen size is 49" high x 87" wide.
The throw distance for this screen for the Infocus 7210 is 12.1' to 15.1'.

Viewing distance for 26deg = 15.7' (Max THX distance)
Viewing distance for 36deg = 11.2' (Recommended THX distance)

If you put the projector almost at the full distance of 15'
Put the back row at 14'6" (They won't bang the proj. when they stand.)
This allows first row at 11'.

If you put the screen 2' off the floor, you would have a foot between the top of the screen and a 7' ceiling. This should be adequate for mounting speaker above.

Remember for a 100" screen the offset is about 7 3/4" to the lens plus several more inches for the projector and mount the screen will barely make 2' off the floor with a 7' ceiling without obstructions. With obstructions the PJ and screen might have to be mounted lower.

BCF's recommendations are good for the seating. With this particular PJ I would use a hushbox if you are going to mount it over or right behind the rear seating as it is loud.

If you want the projector at the back of the room say ~18' to the lens leaving room for the PJ and cabling the minimum screen size is now 119" with a height of 58" and the offset then moves to about 9.5" plus projector and mount. This puts the screen at 1' off the floor and maybe less.

I second the recommendation for the Screen Research screen as the best option if budget allows.

Hope this helps.

Bob

This is way more detailed information than I expected and it is very much appreciated.

By "perf screen" I always meant a woven AT screen such as the SR products. I have yet to get a price sheet on the SR products but there are other comanys that use a woven material. I have seen several of you guys swear by the SR products and if the budget allows then that's the way I'll go. As a side note, many of the bigger receivers do some auto EQing nowadays so maybe a full EQ could be avoided on the Stewart screen. I doubt it.

There are no obstructions in the center of the ceiling, just along the left and right edges of the room. The room length is not set in stone so, base on how the math works out, I was considering pulling the back wall forward so the projector could be put just behind the back seats.

putting all three speakers above the screen is certainly a reasonable solution but if I can make it all work out I prefer ear level for the front three.

I've been playing around with a $70 3D home design software program that I picked up to try and layout an addition to my house. With a little more time invested I think rooms like this could be layed out very quickly and easily in this software. Might be an interesting way to sell the system as well. Maybe all of you have been doing it that way for years now but it's not something I've tried yet.

In my theater, the projector is on a shelf above the door, as you walk into the back of the room. This works quite well, as I've boxed the shelf in, use a small piece of glass with an Anti-Reflective coating for the window, and vent the box to the room outside the theater, to cut down on noise.

This works well, and if I decide to upgrade projectors, no new mount to buy!