Are projector screens transparent to sound?

I am planning a ht room and was wondering if i can put absorber panels behind the screen and would this be effective? Which brands are best for audio?
If it is a solid vinyl substance the answer is no. as far as put the speakers behind the screen. But as for taming room acoustics. I would'nt think the front wall would be a problem for reflection of sound. but hey try it and see. I'd be interested in the resualts you get
Screen material is made of thick vinyl. It won't be very transparent acoustically. I don't think there will be much to gain by placing panels behind it. Usind standard screen brackets I would guess there might be 1" max between the wall and the screen material. you will need to shim the screen out if you want to use thicker panels. A piece of recycled foam carpet pad might be just as effective as acoustic panels in that location. Recycled foam is made with various density foam bits which absorb different frequencies. High frequency will be reflected by the screen itself. I would NOT recommend using a perforated screen. This will degrade picture brightness. Moire effects will also occur with DLP and LCD projectors. Perf screens are also much more expensive.
Unless you have a retractable screen and intend to use the panels for music only then yes it is worth a look at, but as said if your screen is to remain down then no use in treatment the sound wont reach.
Ok. So i geuss i just put wall treatments to the side of the screen. Are most people using absorption or diffusion on the front wall?
If you want acoustically transparent screens, then you would have to consider:
Another company that makes acoustically transparent screens is Screen Research. Their web address is below.
Are these "better" than reflective screens? Do they have the same picture quality?
Perf screens are not better than solid screens. They emmulate what is used in real movie theaters on a smaller scale. At the viewing distance in a real movie theater the human eye cannot see the holes in the screen. It is essentially a giant speaker grille so the L/C/R speakers can be placed behind the screen. Picture brightness is reduced because of the holes. The sound system is equalized to compenstate for frequency responce loss. Stewart makes a very nice home perf screen with frequency response compensator. However, it is much more expensive than a standard screen. In addition, if you are using a DLP or LCD projector, moire effects will appear.

For best acoustic results, place the center speaker tweeter as close to the bottom edge of the screen as you can. Set L/R speaker tweeters near the bottom corners of the screen just outside. I usually shoot for the lower bottom third. Don't go any higher then half way up max. This will give you a near linear pan acroos the front. Use accoustic absorbtion behind the speakers. You want the rear of the theater to be a little more lively for surround effects.

If you are building a room from scratch, you can build a fake wall out of 2x4's. Creat a opening in the center to mount a framed screen in. Wrap the fake wall sections in black grill cloth. Set the wall at least 2' out from the real wall. More would be better if you have room. Acoutically treat the whole area. Now you can mount speakers on stands and install subs where you want behinde the fake wall. You can move and adjust everything just like a real theater. The speakers will preform better because technically they are out in the room. you can creat access around the wall by hiding side openings behind velvet side curtains. You can use any speakers. Cosmetics mean nothing. If space is tight you can access by removing the screen and climbing in.
I've seen many screens, but after viewing a Stewart, nothing comes close, that's why its the industry standard. Of course its not cheap, but you get what you pay for.
Agree with CMK. Get a Stewart 1.3 gain with the wide Delux frame and Velux coating. The extra wide frame looks much more finished than square tube frames. Overspray hits the frame and is absorbed by the special Velux material. After your eyes adjust to the dark you can see the overspray. Velux helps this problem. It will be the last screen you buy unless you change size.
Thanks, Guys.
Any suggestions on where to get a good price on a stewart?
You might check Videogon or ebay. Do not buy a GrayHawk or a FireHawk. These were made for early LCD or DLP projectors with bad black levels. You want plain white 1.0 or 1.3 gain. the latter will give a slightly brighter picture without hot spotting.
AVScience has competive pricing on Stewart screens.

While Stewart doesn't make an inexpensive screen, the price difference may not be too interesting once you've specified the useful options : wide frame, light absorbing coating, and the 1.3 gain fabric.

I paid just a couple hundred dollars more for my 87x49" Velux Deluxe Stewart with Studiotek 130 than I would have a DaLite with the same options.

Also note that the big manufacturers including Stewart will build a screen to any size and shape you want. If you'd prefer 2.4:1 or 1.85:1 they'll do that.
The screen of choice should be the Stewart Screen.
I mounted mine away from the wall and have sound panels behind the sceen which are not visible but make a profound difference to the room. I also elected to to put sound panels beside the screen in my set up.
Back to the sceen, get the wider frame for the screen the one that has the flocking/velour finish on it. Any reflections will not show up with this frame whereas the metal frame with only the black paint will show the reflections. This would drive me crazy, well maybe crazier.
Good luck.
Just thought I'd update this thread with my recent experience.

I recently got a SeymourAV Centrestage XD dropdown 120" screen and it is extremely good. It is not totally transparent (none are) with a very slight attenuation mostly in the treble. I have not bothered to adjust my EQ as it is not a significant effect. Anyway for folks looking for an audio transparent screen this screen is unbeatable value - no moire at all. The screen was built to order with perfect precision, well packed (double boxed) and worked out of the box.

Now I have a TV for regular viewing and music listening with a dropdown large screen for when we want to watch a Blu-ray movie. The sound comes from behind the screen - just as it should or does in the real cinema.
I realize this is a bit off topic, but several of the replies here suggest relevant expertise.

I use my system for both HT and music. Would covering the 100" screen with velvet drapes when not viewing improve depth of 2.1 imaging? The LRC speaker faces are 4' from the rear wall, a wall covered with carpet. The LR speakers are 3' from untreated side walls that are hung with posters. The room is 14' X 19' X 8'. Two dimensional imaging is excellent, three dimensional is good, but I'd like a bit more sense of depth.

I had a fixed screen for years and it drove me crazy for years. When playing vinyl or CD's through the 2 channel system the center image moves as the screen vibrates with the music. It does effect bass also but in my setup it was for the better, made it harder to locate the subs in the front of the room and the bass seemed to be better controlled. I think fixed vinyl screens act like a drum skin.

I finaly purchased a retractable and will never look back, all is good now. Do have to treat room more now for bass but that is easier to deal with.