Ou8thisSN Posted January 21, 2003 Share Posted January 21, 2003 I was browsing the different companies that sell screens for front projectors. I came across a company called Stewart and they have a line where the screens are perforated, meaning have tiny holes so that the center channel can be placed directly behind the screen itself, so that the center dialog truely comes from the screen. Have any of you had any experience with Perforated Screens? It is THX certified... if that means much. I believe in regular theaters they are perforated. Basically I'm concerned if the screen would hamper all the frequencies from being heard fron the center channel. Quote Link to comment Share on other sites More sharing options...
WMcD Posted January 21, 2003 Share Posted January 21, 2003 My recall is that the screen in movie theaters do cause loss of treble. It may be impossible to predict how much and at what frequency. Another matter is that the screen degrades the directionality of the treble horn, and broadens it out. Therefore movie theater horns are designed with a slightly narrower pattern than desired. Gil Quote Link to comment Share on other sites More sharing options...
m00n Posted January 21, 2003 Share Posted January 21, 2003 I would suggest two other forums to ask this question.... http://www.avsforum.com http://www.hometheaterforum.com My guess is that you will get more answers to screen and projector related questions. For my screen, I am using a $20.00 piece of parkland plastic you can get at any home depot. What I then plan on doing is buying some screen goo. It's a special kind of paint for DIY screens. I hear it produces a very nice image. http://www.goosystems.com/ Quote Link to comment Share on other sites More sharing options...
HornEd Posted January 21, 2003 Share Posted January 21, 2003 It is amazing how many times Gil is on target... Yes indeed, the high notes having the shortest wave lengths are stopped by the least resistance... that's why horn tweeters should be aimed at the center of the sweet spot (I use a laser pointer)... you know, the place where you sit... and the significant other would like to. I think in law they call that an attractive nuisance. Right Gil? In professional quality theaters that I have built for my showrooms I have used perforatted screens to good effect... but usually I would mount tweeters by themselves above the screen and aimed at audience segments. Generally, longer waved sounds (below about 2500 Hz) have little or no trouble travelling through the screen. A perforatted screen makes it easier to have the center main match your left and right mains... I like to put the center main a bit higher than the right and left mains since its purpose is to anchor the sound to the screen. The increase in vertical height also allows more of the sound to get past the first row. My suggestion is to try the center main behind the perf screen before you think about separating the tweeter... you might be surprised at how satisfied you may be... I certainly was on more than one occasion! =HornEd PS: Hey, m00n, goo for it! Quote Link to comment Share on other sites More sharing options...
JasN00b Posted January 21, 2003 Share Posted January 21, 2003 --------------- PS: Hey, m00n, goo for it! ---------------- *smack* >=) Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted January 21, 2003 Author Share Posted January 21, 2003 ---------------- On 1/21/2003 8:09:21 PM HornEd wrote: A perforatted screen makes it easier to have the center main match your left and right mains... I like to put the center main a bit higher than the right and left mains since its purpose is to anchor the sound to the screen. The increase in vertical height also allows more of the sound to get past the first row. ---------------- Right, well I'm not really putting together a full scale home theater, as some of you have... which are wonderful, btw. Its basically my parents house, and they love to entertain/ watch tv/movies/etc. So, there's not gonna be like stadium seating or anything like that. I'm planning it to be a rectangular room, with maybe two 7-seating sectional sofas making a "U" shape around a 96-120" inch screen, depending on what the dealers tell me would be best for the Sharp Projector. In this case, would a perforated screen work when the total distance from viewer to screen would be about 15-20 feet, and thats it, no back row. Would I still be losing frequencies? Basically I'm asking if a perforated screen acts like a speaker grill or more like a pillow... I'm considering the RC-7, btw. And I am not a very daring/creative person who would undertake cutting up the speakers to separate the horn from the woofer or anything, so if its placed behind the screen it will stay there forever probably, in one piece. Quote Link to comment Share on other sites More sharing options...
HornEd Posted January 21, 2003 Share Posted January 21, 2003 Frankly, Ou8thisSN, it's harder to give good comprehensive advice when facts are missing. If you are talking about an RC-7 then you must be looking at RF-7's for main speakers... and that makes sense if all of your mains are RF-7's. THE MAIN speaker in HT is the Front Center speaker... Upwards of 75% of the TOTAL sound on a DVD gets pumped through the front center MAIN... why would you want to put a half pint RC-7 (weighing in at less than half an RF-7) in to do a RF-7's job? Yeah, yeah, I know what the salesman probably said... and the RC-7 does great on music where it's job is to bridge the Right and Left Mains... but if you have a big screen... playing music CD's is not why your building this HT! The nice thing about a perf screen is that you can put a whopping big center behind it and get the full impact of anchoring the sound to the screen that many of us can only dream about. The three most important Reference speakers you can put across the front is three matched RF-7's. Anything less is an unrealized opportunity, IMHO. I understand about building an HT for your parents... I spent over $20k building a Klipsch based home theater for mine... one they could still enjoy into their 90's! If your het up on RC-7's... put them in the back of the room as Rear Effects... or on the side as Side/Surrounds... or better yet, get three more RF-7's for a 6.1 system that will do your family proud. Don't forget an adequate subwoofer array... its second in importance only to putting a speaker equal to your left and right Mains in the center spot. Many of the issues you are facing I have already addressed for a Forum Member named Gordon. You can search for the keyword Gordon in the body of the post, set the date for the last couple of days, and put HornEd in as the poster... and you should have half a dozen posts that will apply to what you are trying to do. It is a fine thing you are doing for your parents... make sure the result is just as fine. =HornEd Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted January 22, 2003 Author Share Posted January 22, 2003 ---------------- On 1/21/2003 11:32:16 PM HornEd wrote: Frankly, Ou8thisSN, it's harder to give good comprehensive advice when facts are missing. If you are talking about an RC-7 then you must be looking at RF-7's for main speakers... and that makes sense if all of your mains are RF-7's. THE MAIN speaker in HT is the Front Center speaker... Upwards of 75% of the TOTAL sound on a DVD gets pumped through the front center MAIN... why would you want to put a half pint RC-7 (weighing in at less than half an RF-7) in to do a RF-7's job? Yeah, yeah, I know what the salesman probably said... and the RC-7 does great on music where it's job is to bridge the Right and Left Mains... but if you have a big screen... playing music CD's is not why your building this HT! The nice thing about a perf screen is that you can put a whopping big center behind it and get the full impact of anchoring the sound to the screen that many of us can only dream about. The three most important Reference speakers you can put across the front is three matched RF-7's. Anything less is an unrealized opportunity, IMHO. I understand about building an HT for your parents... I spent over $20k building a Klipsch based home theater for mine... one they could still enjoy into their 90's! If your het up on RC-7's... put them in the back of the room as Rear Effects... or on the side as Side/Surrounds... or better yet, get three more RF-7's for a 6.1 system that will do your family proud. Don't forget an adequate subwoofer array... its second in importance only to putting a speaker equal to your left and right Mains in the center spot. . =HornEd ---------------- Thanks for that, as usual your advice is right on. FYI, i ahvent talked to any salespeople.. yet, because i figure they would be more interested in selling their overstocked inventories more than what I care about. I am thus relying on your and others like you who have plenty of experience to guide me and a sincerely appreciate it. I dont think I can afford all RS-7s for a 7.1 or 6.1 setup. I think I would be plenty satisfied with the R7 series, as this is my first true HT system. (I do have one presently with a Bose AM-10 and an Onkyo THX reciever... the first one they made... I'm learning all the shortcomings about Bose now.. thanks to yall). In any case, since you have made it clear that so much of the dialogue comes from the center channel, perhaps I can mount it directly underneath the screen or something. But I cant get over the excellent imaging that I would get if it was mounted directly behind the screen. But if you really think it will be muffled then I'll scratch that idea... certainly dont want to pay for that speaker then have the performance reduced by half or something. I planned on getting One SVS Ultra sub to start with and then adding an RSW15 in like a year or so, and then get the SVS to handle everything from 30-down and the RSW15 for everything 30 up. How do you feel about that? Quote Link to comment Share on other sites More sharing options...
HornEd Posted January 22, 2003 Share Posted January 22, 2003 I am confused, Ou8thisSN, you said that you didn't think you could afford all RS-7's... why would you want any RS-7's at all... except that they are smaller, cheaper and less effective then RC-7's... let alone RF-7's. RS-7's are the side/surrounds that weigh in at 24 lbs., have one wee woofer aimed at the sweet spot and opposing tweeters that spray everything over 2000 Hz at the front and back walls... undermining timbre with speaker-forced ambience... even when the sound engineer who mixed the DVD hasn't called for it! Perf screens are generally far more costly than other screens. Even big software engineers like the m00n man opt for Kmart plastic with a coat of screen goo (a much less costly alternative)! There are a lot of options running through my head... and knowing the size (LxWxH) of your viewing area would help me and other Forum folk a great deal. I need to go to bed... and leave on a trip in the morning. Maybe we should start over later. =HornED Quote Link to comment Share on other sites More sharing options...
Gordon Groff Posted January 22, 2003 Share Posted January 22, 2003 The great HornEd wrote: "If your het up on RC-7's... put them in the back of the room as Rear Effects... or on the side as Side/Surrounds..." Hey! Why didn't I think of that!! I was so bummed when I realized the RF-7's would not fit for surrounds & rears, I jumped to RB-5II's. I'm gonna mock up some RC-7's and see if I can fit them in! They look a LOT better than the RB-5II's!! Gordon Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted January 23, 2003 Author Share Posted January 23, 2003 ---------------- On 1/22/2003 12:23:39 AM HornEd wrote: I am confused, Ou8thisSN, you said that you didn't think you could afford all RS-7's... why would you want any RS-7's at all... except that they are smaller, cheaper and less effective then RC-7's... let alone RF-7's. RS-7's are the side/surrounds that weigh in at 24 lbs., have one wee woofer aimed at the sweet spot and opposing tweeters that spray everything over 2000 Hz at the front and back walls... undermining timbre with speaker-forced ambience... even when the sound engineer who mixed the DVD hasn't called for it! Perf screens are generally far more costly than other screens. Even big software engineers like the m00n man opt for Kmart plastic with a coat of screen goo (a much less costly alternative)! There are a lot of options running through my head... and knowing the size (LxWxH) of your viewing area would help me and other Forum folk a great deal. I need to go to bed... and leave on a trip in the morning. Maybe we should start over later. =HornED ---------------- 1. sorry about the typo, I meant I cannot affort all RF7s, I can however afford the Reference Series 7 system. I can live without the perfect Timbre matching, all in all would you consider the R7 system to be a good system for entry level home theater-ing? 2. The size of the room will feature upto 1000 square feet. It will be rectangular. I imagine it will be 35 x 30. It will be a general purpose room, with probably a Pool table in one side and 2 sectional sofas facing each other in the other side. the side with the sofas will be where I would like to put in the home theater setup. We're not going for a true home theater feel, we just want a huge screen because to us it seems silly to put a 60" RPTV in a room that big becuase it will still look small. We want to get anywhere from 100" to 120" screen. This is the equipment I'm considering: Klipsch Reference Series 7 Denon AVR 5803 SharpVision XV-Z10000 or 9000, big screen. This will probably be a custom built house so I want to get the equipment in place while its being built. We ourselves are not as adept as most of you so we wont be drilling or anything like that after the house is done. This is why I was wondering if placing the center channel, the RC7, without the grill, in front of a perforated screen would sound the same as if it would have sounded if it did have the grill was on. Would the perforated screen have the same or worse effect as a speaker grill? Quote Link to comment Share on other sites More sharing options...
HornEd Posted January 23, 2003 Share Posted January 23, 2003 For all you are planning to do, it is a little surpring that you would take a lot less performance from an RC-7 than you could have for just a wee bit more and put a timbre-matching floorstanding RF-7 behind a perforatted screen. And, yes, taking the grille off the speaker that is behind the screen is advisable... but that's a crumb compared to leaving a whole loaf on the table by opting for the RC-7. Good luck and let us know how it goes. The Reference system is a great system for most people... and if you are building a custom home with a listening area that big... you better be prepared to spend some dough. I use Heritage to fill up that kind of space. =HornEd Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted January 23, 2003 Author Share Posted January 23, 2003 I'll take that into advisement... if you're that adamant against the RC7, perhaps I can consider it. I still have about 6 months before I decide. Perhaps prices may come down a little by then... If I had an RF7 behind the screen, would you advise me to put it behind the screen or no? I mean, if you were in my shoes, with my budjet (which is a lot less than yours since you can have the big boys ), then would you place it behind the screen or underneath? Also, how much of a price difference would there be for a perforated screen versus a standard screen? Also wondernig if you know anything about an electro masking system as well. I cant find pricing information online, just descriptions. Just wondering if you had any ballpark ideas or even know a site that does have pricing information. thanks Quote Link to comment Share on other sites More sharing options...
WMcD Posted January 23, 2003 Share Posted January 23, 2003 Thanks H. Ed. Going further, I'd think in HT setups, it is fairly typical to have the center behind the screen and the flanking R and L out in the open. That would cause a major problem with the center, alone. In movie theaters all three are behind the screen. Therefore you have the same problem with all three, which might be easier to solve. At least you might find the same solutions for all three. I think H. Ed is almost correct that this is a wavelength problem, but not quite. Wave mechanics generally says that to radiate a wavelenth, or block it, the item must be about a wavelength or greater. At least to work with efficency. Here the real problem is accelerate a mass with a force to get an acceleration. Newton said that F=MA. So if you want to drive a mass at high accelerations (changes of velocity) you need more force. But if force is constant, high masses don't accelerate very well. Light weight cars accelereate well. You have to realized that making a mass move back and forth at a sine wave function is a type of acceleration. To move it back and forth quickly (high frequency) is a type of high acceleration. The wave mechanics and F=MA help us with tweeters. The wave length is small, so the diaphragm can be small. The acceleration is high. But the latter is okay because, being small, the diaphragms are light weight. Coming back to the issue. The screen in front of the tweeter has a finite mass. So it is difficult to move it at high frequencies by creating air pressure (from the speaker) on the back of the screen. This is a way of saying the mass doesn't move much at high freqencies, or response drops off at high frequencies. A partial solution is to have holes in the screen. Then the sound pressure just passes through the holes. However, we need a good amount of screen surface (fewer holes than we might like) to reflect light. Speaker grill cloth is relatively "holey" compared to the projection screen. You should be able to breath through it. This is to say it has a lot of holes. The pressure, and gas flow, passes back and forth. Please consider that the mass of a wall has the property of blocking high frequency much more than low frequencies. Better said, it is difficult to get a wall to move quickly by sound pressure on the neighbor's side. This why you hear the bass notes of a neighbor's system, and not the treble. About the only way of stopping bass transmission is to have a more massive wall, or two walls which ar not in physical contact through common studs. On the other hand, stopping up holes in the wall is important isolation issue to stop pressure leakage. It takes some hazy thinking, but it all works out. Gil Quote Link to comment Share on other sites More sharing options...
HornEd Posted January 23, 2003 Share Posted January 23, 2003 Thanks Gil, I'm having a hazy day... I meant to suggest having all three speakers behind the screen without grilles. The grilles don't do much but they are another impediment. My first thought would be to try all three floorstanders behind the perf screen and give it a personal ear check. Klipsch tends to be a little bright, and that particular screen just might tone them down. lol Maybe it is my hazy day mind, Gil, but I don't think that was the clearest post of yours that I have ever read. Yes, it made sense, but some how I thought a brilliant solution would tweeter out (rather than peter out as mine did) at the end. Looking forward to an elegant reprise. And, thanks for stepping in... I had left more than a participle dangling. =HornEd Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted January 23, 2003 Author Share Posted January 23, 2003 Gil, HornED, excellent posts. Although I would love to create the least resistance and get best sound/visual quality, and since I was only trying to put the center channel behind the screen and not the others, I think it best that I dont get the perf screen and mount the center channel directly under the screen. Like I said, I can barely afford the R& series as it is, and I dont think I probably could afford a perf screen anyway, it was just a passing thought. I dont really want the screen to act as a barrier, and when i do go to movies in the theaters, I do find the trebel a bit lacking, so I think I'm just gonna go with a normal screen. Do you guys have any favorite manufacturers between Stewart, Dalite or others? and what type of screen is good for a projector that puts out between 1100-900 ANSI lumens. Quote Link to comment Share on other sites More sharing options...
tripod Posted January 23, 2003 Share Posted January 23, 2003 ---------------- On 1/23/2003 9:51:51 PM Ou8thisSN wrote: Like I said, I can barely afford the R7 series as it is, and I dont think I probably could afford a perf screen anyway... ---------------- Don't forget, as far as speakers go, you're only looking at the price difference between the RC7 which comes with the standard Reference 7 set and a third RF7 which you would be replacing it with. Unless I'm mistaken, that difference should be only a few hundred dollars, not much considering you are spending several thousand all together. I don't know about screens, but it seems like the most sophisticated arrangement would be to have a perforated screen with 3 RF7's behind it and the RS7's for your surrounds. Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted January 24, 2003 Author Share Posted January 24, 2003 HornEd, since you are so dead against the RS7s to be used as surround speakers, much less anything else, how about a setup with RF7s, RC7 and 2 RF3 IIs to be used as the surround speakers? they go lower than the RS7s. Would this be a better choice. I know timbre matching is still an issue, but I cant go all RF7s. If you were in my boat, would you get a pair of RF3s or a pair of RS7s as the rear surrounds. I'm thinking that the RF3s might be so bad, as they are actually cheaper than the RS7s, and seem to be a better speaker, except that it is monopole. If a speaker is monopole, and THX demands it to be dipole, does that mean that THX SurrEX or other THX post processing modes would be rendered completely ineffective? Quote Link to comment Share on other sites More sharing options...
HornEd Posted January 24, 2003 Share Posted January 24, 2003 No doubt about it, Ou8thisSN, THX has become a joke... a bad joke as far as building an HT today. Your monopole system will handle everything a THX processed flick can dish out... and many people, me included, think the THX sound comes through better on monopoles than the cheaper little sound sprayers they recommend. Actually, the new THX standards are less rigid on the surrounds and even favor monopoles as rear effects. As you may know, Lucas Films, sold 80% of its THX experiment in gathering licensing fees to a firm in Singapore that's "certifying" just about anything it can make a buck on. They bought controlling interest in THX for $8 mill. Do you think George Lucas would have sold it so cheap if other studios were making a lot of films using his experimental parameters? Now dts is something worthwhile... and Dolby Digital is trying to stay a close second quality wise... but THX has no major following except by Lucas Films. Most new receivers will cover Dolby Digital and dts... you may also see THX (for its hype value) but essentially that is Dolby Digital with a tricked-up bass. As far as the side/surrounds go, THX mixes for ambient sound in those channels... so your monopoles will put out the ambient sound that is sent to them. If you have bipoles or (worse yet) dipoles, that ambient sound will be sprayed around the room more but your monopoles will probably provide more quality sound than the THX style speakers. Even the smaller monopoles you mentioned are bigger and more robust than the RS-7's... and at least they will provide a timbre match where the RS-7's will tend to fuzz up the timbre and directional issues... particularly on non-THX material... and that's just about everything but Star Wars these days. Clearly, the front array in HT is the most important... particularly the center speaker. Three RF-7's do a great job up front providing there is an adequate subwoofer bringing up the rear. Sliding three RF-3 II's in to do the less critical rear array chores will likely give you your best HT bang for the buck! There's a new HT world coming because five (or more) discrete channels to work with gives auto engineers the opportunity to vie for an Oscar by using all those channels to selectively create directional and/or ambient sound at the same time as the script requires. Having side/surrounds modled after the weak surround channel of bygone ProLogic days doesn't make sense for the DVD's and music of today... and tomorrow. =HornEd Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted January 24, 2003 Author Share Posted January 24, 2003 The Denon 5803 and 4800 series only differs by THX post processing and offering 7.1 channel amplification. If you say THX is bull****, and 7.1 is a mix of 6.1, would I be better off with the 4800 amplifier or is there a redeeming value for the 5803? Again, if you were in my shoes which would you pick... I think I can afford the 5803, but i'd rather save money if there wasnt a great need. Quote Link to comment Share on other sites More sharing options...
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