AVS Forum | Home Theater Discussions And Reviews

AVS Forum | Home Theater Discussions And Reviews (http://www.avsforum.com/forum/)
-   Screens (http://www.avsforum.com/forum/23-screens/)
-   -   Size & perforation question (http://www.avsforum.com/forum/23-screens/19636-size-perforation-question.html)

ClaudeD 04-04-2000 07:35 AM

Due to space limitations, I will probably have to get a perforated (THX) Stewart 1.3 gain 16:9 screen. Main seating will be 14' from the screen, using a Sony VPL-VW10HT LCD projector.

The two sizes under consideration are 110" diagonal (96" wide) and 100" diagonal (87" wide). How objectionable will the perforations be? Is the 110" screen too big at that distance (i.e., will I be going cross-eyed at 32 degrees of view)? Will the 100" give me sufficient immersion factor (after being accustomed to 65" screen)?

Thanks in advance for your input,

Andrew Low 04-04-2000 08:05 AM

I'm sorry but I can't comment on the perforations.. but I can comment on screen size as I've been trying to decide myself.

I think that a 32 degree field of view will be very comfortable for all audience members, you may even consider sitting closer.

I think that somewhere around 35 degrees gives a "immersive" effect -- but really its personal preference. Just make certain that you've got a high enough resolution image on that screen, otherwise image quality is going to drive you nuts. I tend to get googled eyed around 45 degrees.


Brett 04-04-2000 12:29 PM


Kjohn had a similar question in this forum regarding screen size, and was inspired to start a survey in the CRT forum about screen size. Here is the link.



Dennis Erskine 04-04-2000 06:59 PM

A proper acoustically transparent screen will not produce noticable problems at a correct (or further) seating distance (and a 35 degree subtended angle is excellent for a line doubled picture (or HDTV). Actual measured light loss is in the 8%-10% range. Make certain there is nothing reflective behind the screen.

D. Erskine
DEsign Cinema Privee
Imagine what you could do, if you could do all you imagine.

ClaudeD 04-05-2000 05:53 AM

Brett, Thanks for the pointer to the "size" thread; I ran across Darryll's post with an identical screen, and have e-mailed him.

Dennis, thanks for the tip about the area behind the screen; hadn't thought about that. I am/was planning on having a smaller direct-view TV back there, but perhaps I'll have to have some cloth that I can drop down over the little TV so that I don't get reflections off its screen.

gages 04-08-2000 07:30 PM


What did you decide?

I currently have a Vutec 103" diagonal screen and I sit about 11.5' away. Problem is that my speakers (l c and r) are about 6' behind the screen. With the screen down (even though the leader is perfed) I am getting fairly muffled audio.

I spoke with Dennis E about this and Dennis states that the issue is related to the fact that at 6' away the dispersion pattern of the speaker is such that the bulk of the audio output is hitting the main part of the screen (makes sense!)

This definitely puts me in the market for a completely perfed screen. I am also concerned as I have my direct view TV as well as audio/video equipment (with associated LED's) behind the screen.

Based on Dennis' strong recommendation I am also considering the Stewart 1.3 w/ a 103" diagonal (BTW Stewart will make any size you want at no additional cost).


ClaudeD 04-09-2000 08:18 AM


I haven't ordered it yet (next few days), but I'm strongly leaning to the 110" 1.3 Stewart with their "THX" perforations.

I called Stewart, and they maintain that the perforations start to disappear at about 10'. So, I'm hoping to be okay at about 14'. They also mentioned that they could perforate the black part of the screen; I hadn't thought about that.

My L/R speakers will be inches from the screen, the center will be maybe a foot or so. I don't think that dispersion will be a problem.

It sure makes me nervous, but I can't figure out a way not to have my speakers behind the screen in my small room.


gages 04-09-2000 10:50 AM


I hear you. It definitely concerns me to spend at least 4k and not be sure whether it will work well.

With your speaker to screen distances you should be fine. Dennis explained to me that the rolloff on the Stewart THX microperf is something like 2db versus other manufacturers at something like 45db.

You need to be carefull about reflectivity behind the screen, not just your direct view TV. Other glass items of LED's may be a problem.

You should definitely perf the leader part of the screen also.

My concern is the fact that my speaker to screen distance will still be 6'.

Why don't you email me and maybe we can get a "powerbuy" going.


[This message has been edited by gages (edited April 09, 2000).]

Ted White 04-09-2000 02:19 PM


How wide is your room?


ClaudeD 04-10-2000 05:55 AM

Steve, e-mail will be sent later today.

Ted, since I've encountered delays in building my dedicated home theater, this room is a family room serving double duty. Width is kind of hard to pin down, since the layout is that I'm on one end of a very long room (kitchen one end, family room other end). I guess that the family room "half" is about 18' wide by 19' long. The problem is that on one side there are built-in bookshelves (removal requires divorce), on the other side there are French doors to another part of the house. So, the workable area for speakers is only about 6' wide, right behind the screen. Putting the speakers under or to sides of the screen would be very inconvenient for the shelves and the door, and would really require moving them whenever they were going to be used (too much trouble).

I'm not bothered by the smaller soundstage this causes, I'm willing to believe that it will probably sound okay for movies (serious music listening will be with screen retracted), and I guess that I'll cross my fingers about the visibility of the perforations.


[This message has been edited by ClaudeD (edited April 10, 2000).]

Dean McManis 04-10-2000 01:54 PM


I'm toying with the idea of getting a perforated screen too, but I do have the concern that with the speaker close to the screen fabric that there may be visual distortion due to the close proximity of sound vibrations blurring the pitcure.

Has anyone with a perforated screen tried this out or had problems with this? It's just something that I read, so I'm checking to be sure.


LeeAntin 04-10-2000 09:29 PM

I have both a Stewart 1.3 Gain and Silver 4.0 Gain perforated screen. NOT the THX screen but the regular perforated screen.

I just put on the Silver 400 as my projector is 2 years old and has lost some of its brightness (PRO900X)

The perforations on the regular perf Stewart are small enough that they dissappear from 14' away. The regular perf screen is much cheaper than the THX screen. My 60"x107 with both screen was $1,700.00.

My speakers are 3 inches from the back of the screen. I used a king size black bed sheet from JC Penny to cover the area behind the screen to remove reflections.

The speakers are Infinity Kappa 6's (3) each with 10" woofers.

I find the sound to be very natural and though the screen/bed sheet will stop some of the highs, I find it sounds more like a movie theater than a Home theater due to the fact that all DD 5.1 soundtracks are very "bright" to begin with.

Anyone in the Long Island area is welcome to come see the regular Stewart perf screen at Lee's Bijou.


Jmartin 04-10-2000 10:04 PM

Lee, I gather you have at least one speaker behind the screen, and with 10 inch woofers do you experience any woofer mediated image shaking/instability?....if you have all three speakers behind your screen, what happens if your are viewing Jurassic Park? At "Punchy" levels, does your screen vibrate or distort the image?? very interested in your observations!

ClaudeD 04-11-2000 05:47 AM


That's very reassuring. Presumably the microperfs would be even less visible. I can deal with -2db @20KHz, but I wouldn't want the screen to be my EQ mechanism for overly bright movies http://www.avsforum.com/ubb/wink.gif .


LeeAntin 04-11-2000 06:32 AM


I have all three "screen" channel speakers behind the screen. I also have four 12" subwoofers below the screen for the LFE channel.

The only way to put large speakers behind the screen is to use a bass cutoff of 100 KHZ. This will make sure that the screen will not vibrate from the low bass air that is being pushed by the driver. All DD processors have this cutoff feature.


I have seen the THX Stewart screen and to be honest, I do not like it at all for the following reasons:

1. A lot of light passes through the screen. When I saw it at the 1996 CES show in Vegas it was mounted about three feet away from a grey carpeted wall. When you looked behind the screen you could see the image!

2. The image takes on a very glossy look that I found to be very unnatural. The people that I was with also did not like it.

My suggestion to anyone who is considering a THX screen is to take the time and go see it, even if it means getting on an airplane.
They are expensive and as far as I know, once you buy one, you own it and cannot return it.


Dennis Erskine 04-11-2000 01:32 PM

The Stewart, by itself, has a maximum 2dB rolloff at 20kHz. On the other hand, the difference between their MicroPerf and THX MicroPerf is nothing...except for the little black box they send with the screen and the logo. The black box compensates for the screen roll off characteristics ... you don't need to use it if you're using an equalizer.

The light loss ranges between 8% and 10% for a Stewart Microperf. I have not seen the numbers for any other manufacturer. 10% loss in brightness cannot be perceived by the human eye. When 100% bright is side by side with 90%, we perceive the difference as 1%.

Rather than being concerned, however, with the loss of light, I'd suggest a better metric would be to determine the actual Foot Lamberts of the screen. For example, if you're getting 20 foot lamberts with a standard screen and 18 with a microPerf, why'd you care? 18 is very @#$# bright (and exceeds the standards for a commercial theater). On the other hand, if you're at 7 (below standard for a home theater), I'd suggest no microperf if not a smaller screen.

D. Erskine
DEsign Cinema Privee
Imagine what you could do, if you could do all you imagine.

LeeAntin 04-11-2000 01:33 PM


You really have to make a decision as to what use your "system" will be; ie: movies, music or both.

I have a dedicated Home Theater that looks like a screening room. The room and equipment is designed around watching movies which is 99.9% of the time.

When soundtracks are transfered to a medium be it DVD, LD, VHS, DBS, etc they use something called an Aceademy (spell check) Curve. Everything above 14,000 kHz is rolled off. The human ear can go as high as 16,000 but no where near 20,000.

The soundtracks for real theaters are pumped up at the treble end for the loss that horns have going through the screen which is thicker than a HT screen. No one uses horns in a HT system. Horns are designed for big rooms like movie theaters. The idea is to have the people in the back of the theater hear clearly while not blowing the people in the front of the theater, out of their seats.

When you place speakers behind a screen you accoplish two very important things:

1. All speakers are on the same plane so when sound is panned from L to C to R the sound will be natural as opposed to having the sound on two different planes like a RPTV where the C Channel is above the screen.

2. The C Channel is located at "screen center" which is where directors place the actors faces. This allows the sound to come from the actors mouth, rather than above or below.

Both of these aspects will heighten your movie experience...like a subwoofer will with explosions and such.

Yes you will lose some of the highs and if this will disturb you than you can use a 3 channel EQ made by Rane Corp. to bring them as high as you want. Just make sure that any EQ is done after the processor and not before.

Personally, as I have said, I like the drop in treble as it is not great. Just enough to tame digital soundtracks. The sound is not muffeled in any way.

Claude, I live 17 miles from the Throggs Neck Bridge. If you live near the GW Bridge it would be less than an hour to my house. The same for the Staten Island Bridge.


Dennis Erskine 04-11-2000 05:12 PM

The JBL Synthesis Home Theater system uses true horns (the horns are switched off and conventional drivers switched on for music modes). Just FYI.

Actually, if you place all three speakers (L/C/R) behind the screen, they will not be on the same plane from the listener's perspective. The channel delay circuits in the surround processor compensate for this.

In many cases, you cannot have all three front speakers behind the screen. For example, under optimal conditions with an 8' wide 16:9 formatted screen, and sitting at the recommended distance for a line doubled picture, your speakers need to be 9' feet apart ... just outside the width of the screen.

However, the effect of the center channel behind the center of the screen is memorable.

D. Erskine
DEsign Cinema Privee
Imagine what you could do, if you could do all you imagine.

[This message has been edited by Dennis Erskine (edited April 11, 2000).]

LeeAntin 04-11-2000 06:17 PM


When I said "nobody uses horns" I meant the horn arrays that are found in commerical movie theaters. I know JBL uses them as does Klipsh.

I will not argue your point about having speakers all on the same plane. I do know that it is one of the requirements for commerical THX theaters and most good DD decoders have a Center Delay, but that is to make sure that the sound reaches the viewer at the same time as the L & R speakers which are further from the viewer than the C Channel.

It is almost a moot point as there are no real "directional" sound movies anymore. All the voices come from the center channel with the music and such from the L & R channels. Not like the old days then an actor walked across the screen and was talking, the sound would move from one channel to the next, depending on his/her movement.

To me....personally.....a home theater is just that...a personal movie theater and movie theaters have perforated screens. I have been using a perforated screen for 10 years.


ClaudeD 04-11-2000 09:31 PM

Lee, scratch what I said about being reassuring.

Do you (or Panaramax) know how the screens differ in attenuation? I saw somewhere that the THX version rolls off 2db at 20KHz, is the regular Stewart screen similar?

I don't mind the light seeping through the screen (i.e., the Sony 10HT is very bright), but I don't like the image of unnatural and glossy.

Oh, if I only had that dedicated room ...

Thanks again,

ClaudeD 04-12-2000 06:12 AM

Lee, Dennis, et. al.

Lee, I have been forced to make a decision about what use the system will serve. Since I've had to postpone the building of my dedicated theater, it will have to provide music and film.

When listening to music, the screen will be up, and (if I'm seriously listening) I can move the speakers to provide a wider soundstage. For films, usually the speakers will remain behind the screen, and only about 6' apart. I actually somewhat prefer that narrow soundstage to a much wider one (you know the type -- car sound goes from center of screen to across the room while the car tail is still visible on screen).

Dennis, I don't know the foot lamberts that will result, but I have to assume that a Sony 10HT, praised for its brightness, will provide more than enough light.

For better or worse, I ordered a 110" 16:9 StudioTek 130 screen with THX microperf yesterday. I'm expecting to be happy with it, if not, there's always ebay http://www.avsforum.com/ubb/wink.gif .


Dennis Erskine 04-13-2000 01:48 PM

When I said "nobody uses horns" I meant the horn arrays that are found in commerical movie theaters. I know JBL uses them as does Klipsh.
The horns in the JBL Synthesis are exactly the same used in their professional theater gear (as are many of the other components).

I will not argue your point about having speakers all on the same plane. I do know that it is one of the requirements for commerical THX theaters and most good DD decoders have a Center Delay, but that is to make sure that the sound reaches the viewer at the same time as the L & R speakers which are further from the viewer than the C Channel.
Actually, the THX requirement for consumer equipment requires delay and spl settings for all channels (including the sub-woofer). As an aside, the THX requirement also insists on certain ergonomic requirements with respect to the operation of the menus, front controls, and rear "attachment points".

D. Erskine
DEsign Cinema Privee
Imagine what you could do, if you could do all you imagine.

aerialman 04-22-2001 05:59 PM

Just a quick question about reflective objects behind a stewart micro perf screen- would a typical center channel tweeter be too reflective? what if you kept the speakers grille cloth on?

- Jerry

LeeAntin 04-22-2001 10:55 PM


Are the tweeters in your speakers metal? There is no reason why you can't leave the grills on to make sure that there are no visual reflections.


aerialman 04-23-2001 03:56 AM

Hi Lee,
thanks for responding- the tweeters are metal. Im beginning to think how I want to set up a future ht for my family where the requirement is both music (maybe 30%) and ht but I prefer a theater sound with more musical speakers- just a personal preference. I also prefer a really big screen- at my seating distance (not set yet, but btwn 14-18 feet) I should be between 2.7x screen height and 3.2x- which is just about right. this big screen doesnt leave a lot of space for a center channel beneth it and being so low and close to the floor, I think causes more sonic problems than behind a micro perf screen. So Im thinking of how the micro perf works. I read that the best setup is where the center channel is around 10" back and centered where most actors mouths are usually presented on film. I dont know if thats the dead center of the screen or a little below. Ill probably just place it center and on the same height as the tweeters of the L & R speakers. I know to keep the space behind the screen black. For me that will be very easy. Im also reading that stewart supplies a re-eq box - do you know anything about that functions and if it enters any sonic degration?

- Jerry

LeeAntin 04-23-2001 05:30 AM


You are talking about the THX approved Micro-perf Screen. Is there a reason why you are going with this expensive screen? Are all three channels going to be behind the screen or just the Center Channel?

You can use the "regular" micro-perf screen with seating between 14 and 18 feet back from the screen. When playing music, I would assume you would be only using the L & R channels for Stereo. To compensate for any lost treble from the center speaker you can always pickup an inexpensive graphic equalizer and tune up the Center. Personally, I don't use one. Digital soundtracks have a tendencey to be bright to begin with so going through the screen tames them down.


ClaudeD 04-23-2001 11:53 AM


In practise I've only found a few objects that are objectionable behind the screen: a direct-view set without a flat screen and LEDs (I simply cover them up with electrician's tape).

I doubt a tweeter would be a problem.

P.S. I sure was surprised to see this 1-year old thread show up again.

aerialman 04-23-2001 12:17 PM

thanks for the info. I guess this is one of those oldies but goodies http://www.avsforum.com/ubb/smile.gif

actually I hadnt thought whether this was the thx or regular stewart microperf screen, at this point its just something Im thinking about so Im trying to get educated. Is the only difference the re-eq box that stewart sells? it will only be the center channel behind the screen. As I use a meridian processor, I would want to listen to music in trifield mode so the center is important for music as well.

- Jerry

LeeAntin 04-23-2001 02:27 PM


They are two totally different screens. The regular micro-perf (MP) is a regular screen with very small holes. They dissappear at 14 feet and back from where your eyes will be from the screen.

The THX MP Screen doesn't look like any screen you may have ever seen. It is hard to describe other than the fact that sound will not be obsucred at all. It comes with the re-eq though I don't know why because the screen passes something like 99% of sound.

The only suggestion I have for you is to get in contact with Don Stewart of Stewart FilmScreen Corp. You can probably get his e-mail address off of one of his posts in this Forum. Ask him to send you both literature and a sample of each of the MP screens so you can see for yourself.

Personally, I have seen the THX MP screen and I don't like the look the image takes on. It has a metallic look to it and when I looked behind the screen, i could easily see the entire image almost as bright as the one on the screen itself.

If you place the L & R speakers on the sides of the screen and as i said, buy a graphic eq. you can compensate for the treble loss that the screen creates.

Tell me how you make out either here or by e-mail,



aerialman 04-23-2001 04:30 PM

thanks- Ill let you know how it goes- but it could be a while as I dont need to make a decision on this for over 6 months.

- Jerry

All times are GMT -7. The time now is 01:50 AM.

Powered by vBulletin® Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
vBulletin Security provided by vBSecurity (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.