I'd like to hear from anyone with any hands on experience with perforated screens.
I have been doing some experiments with a perf Da-Lite screen and have been greatly encouraged
by the results so far.
Anyone tried perf and abandoned it? Any tips or tales wanted!
I had the same question. If you use the search option in SCREENS and look for THX screens, you will find a lot of interesting discussions.
I have the 1/12 octave test results on the DaLite. While I am not at liberty to pass it on, let me suggest I use a Stewart MicroPerf.
One other thought ... the DaLite material is not THX. There are only two possible reasons for this:
1. it wouldn't pass;
2. it was never tested;
There are only two reasons for not testing the material:
1. it wouldn't pass;
2. DaLite didn't think it was important.
Da-Lite is an excellent company with many excellent products. On the other hand, I have the 1/12 octave test results and a Stewart MicroPerf.
DEsign Cinema Privee
Imagine what you could do, if you could do all you imagine.
I had temporarily a Da-Lite AudioVision. I replaced it because I could see the holes from 15' distance and the pixels of my XGA DLP projector had some kind of nasty interaction with the holes which caused a loss of resolution.
One other problem was that I have reflective surfaces and equipment with displays behind the screen. Sometimes I saw annoying reflections and lights.
What I want to say here is that you should be very careful when deciding for a acoustical transparent screen. There are not only acoustical drawbacks, there are also other things to consider.
[This message has been edited by Emil Naepflein (edited 12-18-2000).]
I currently have a DaLite Audiovision screen and heard horror stories about sound attenuation, pixel gap moire, and low frequency vibration distortion with full frequency fronts.
I think that the sound is fine, but I have electrostatic speakers which are naturally bright, so I might not notice if there was a slight falloff in high frequencies.
I didn't have any pixel gap moire problems, but I have a D-ILA FPTV and an ISCO 16:9 lens which combines for minimal visible pixel gap getting to the screen.
Even with heavy bass scenes and 8-12" woofers up front I haven't seen any picture problems from a vibrating screen (from any distance).
With my first G1000/ISCO FPTV setup I couldn't see the perforations from 10 feet away, but when I upgraded to a G15 (about twice the brightness) I could see the perforations during bright scenes up to 13' away and had to back up the main seating to 15' away, where they are not visible anymore.
I also had problems with the brighter image passing through the screen and reflecting off the back wall and the speakers metal components.
I had to cover the back wall and shiny bits with black felt to stop the reflections, but it looks fine now.
I will be testing the Stewart Grayhawk perforated screen soon, and will be able to compare both the screen's picture properties and audio quality compared to the DaLite screen.
I think I prefer the slightly larger array of the Dalite.
The THX specs did not envision electrostatic technology ,I think.
I have used a Stewart Micro-Perf screen for 10 years. I am on my third one (now 60x107 Silver 400. Absolutely love it. The ability to have voices coming from the actors mouths and such is worth any loss in high frequency sounds. My equipment is used 99.9% for movies so the loss does not bother me at all as movies are artifically created soundtracks anyways.
If I listened to music, then I would only put the Center channel behind the screen and leave the L & R outside of the screen. In my case, all speakers are behind the screen. No probelms what so ever even with all screen channels set to full with 10" woofers in each of the speakers. My subs (4-12" units) are below the screen.
In the case of the Stewart MicroPerf, you MUST be 14 feet back from the screen so you will not see the perfs.
Is this with a Dila? What projector are you using? I am a bit worried.
In your last statement did you mean DaLite or Stewart? I plan on sitting much closer than 14' with a Stewart THX Perf. Even the DaLite didn't seem that bad.
I have a Stewart micro-perf 130 screen (96x54). With a Sony 10HT projector, I was getting moire effects. Moire was essentially cured by using a Cygnus de-pixelating lens attachment.
Apparently, high resolution fixed panel displays cause this effect with the Stewart micro-perf. Stewart was willing to replace the screen, but I decided to keep it after I tried the Cygnus.
You do have to take care to cover reflective and/or bright things behind the screen. Since my A/V equipment is behind the screen, that took a bit of doing. I also use an IR repeater, though the screen will let most remote IR through.
Acoustically, it is wonderful. Psychoacoustically, it is wonderful to have dialog coming from somewhere near the speaker's mouth.
If Dean is not able to see the perfs from 15 feet on his DaLite Audio Vision, I must conclude these will definitely NOT be visible at the same distance on the Stewart. Unless, a) Dean is rapidly loosing his sight http://www.avsforum.com/ubb/wink.gif, or b) the DaLite has mysteriously surpassed the Stewart in quality. I always thought the Stewart perf structure/size was much much smaller than the DaLite's own. In fact I've heard the size of them holes on the DaLite described as "dime sized", whereas "staple sized" on the Stewart.
I am actually very concerned because I have already build my proscenium to hold an acoustically transparent screen. There is no room to build side speaker enclosures at this point. My room is 17' long x 10' wide, with first platform seating at 11' from screen.
My projector is a Zenith PRO900X. I have the "regular" Stewart MicroPerf, NOT the THX Screen that Stewart offers. For the THX screen you can sit a bit closer...say 12 feet away.
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