speaker placement behind microperf - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 18 Old 03-25-2001, 05:04 PM - Thread Starter
AVS Addicted Member
 
thebland's Avatar
 
Join Date: Jan 2001
Location: Detroit, Michigan USA
Posts: 23,963
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 285 Post(s)
Liked: 151
I have three identical LCRs (Citation 7.2). What is the recommended way to place speakers? Do you use insulation all around them? Mine will be butted against the front wall (behind the screen - about 6" from the wall). How do you minimize rear reflections and improve imaging in a microperf situation? Thanks Jeff

My Home Theater of the Month- Le Petit Trianon

There are more than a handful of [op amps] that sound so good that most designers want to be using them as opposed to discreet transistors. Dave Reich, Theta 2009
thebland is online now  
Sponsored Links
Advertisement
 
post #2 of 18 Old 03-27-2001, 07:39 PM
 
Vic C's Avatar
 
Join Date: Feb 2001
Location: Glendale, AZ 85306
Posts: 2,637
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I have seen a few installs where the speakers are placed behind the screen.

You dont have to wrap the speakers with insulation. If the back wall really is prone to vibrations you may want to use some sound foam like the kind used in studios or even place some foam squares on areas that seem to be the most problemed. As far as reflections go, there always eem to be unwanted reflections but I think if there are any in the cavity behind the screen the screen itself will help to absorb them and not let them interfeer with the main sound that will be coming through the screen itself. What I would try to do is place the baffel side as close to the screen as possibe to allow the most directivity to get through the screen. Keep in mind of cours that the closer you get the woofer it may cause the screen to move and you dont want that either, just be reasonable with placement.
If all your planning to place it the Left Center and Right behind the screen I dont think you will have too much trouble. I have seen subwoofers placed behind the screen as well and as big as subs with 10" woofers. They are kept farther back as to not couse the screen to distort.
Just try certain things if you seem to have problems. Using sound foam should help though in soaking up "hollow" sounding areas behind the screen.
Vic C is offline  
post #3 of 18 Old 03-29-2001, 09:50 PM
Member
 
bnewton's Avatar
 
Join Date: Feb 2001
Location: Norcross, GA
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I'm planning to do something similar in my theater. I will put my center channel behind the screen for sure, but have made provision to allow the L & R speakers to be either behind the screen or on either side of it (behind fabric proscenium walls). I plan to put them wherever they sound best. I'll also put my sub(s) behind the screen, but they won't actually be behind the screen itself, but below it behind the "screen wall" where the screen is mounted. The screen itself will be a Stewart THX Microperf.

I plan to place the speakers behind the screen pretty close to the screen. There won't be much room behind the screen, so the speakers will also be close to the wall. This is generally bad, so my solution is to line the wall completely with that Johns-Manville Theatershield fiberglass product. That's supposed to do a good job of absorbing the near reflections and keeping the speakers from sounding like they are too close to the wall. It also has the benefit of being flat black so I won't get light reflections back through the perforated screen.

I would suggest a similar approach for you. The sound-absorbing fiberglass materials are supposed to work pretty well for this situation.



------------------
Barry
bnewton is offline  
post #4 of 18 Old 03-30-2001, 04:43 AM - Thread Starter
AVS Addicted Member
 
thebland's Avatar
 
Join Date: Jan 2001
Location: Detroit, Michigan USA
Posts: 23,963
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 285 Post(s)
Liked: 151
Thanks Barry. Perhaps the center only behind the screen is the best compromise (with heavy insulation). Esthetically I have to figure out procenium issues and speaker placement (oh, yes, and those pesky subs to place). I haven't priced out the Stewart THX microperf. What did you pay (if you don't mind me askin')? I am in the market for a 16:9 92" wide version. Thanks Jeff

My Home Theater of the Month- Le Petit Trianon

There are more than a handful of [op amps] that sound so good that most designers want to be using them as opposed to discreet transistors. Dave Reich, Theta 2009
thebland is online now  
post #5 of 18 Old 03-30-2001, 06:43 AM
Member
 
bnewton's Avatar
 
Join Date: Feb 2001
Location: Norcross, GA
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I'm actually waiting for a quote for my Stewart screen, I don't have it yet. The theater is under construction. I'm actually pretty worried about what I'm going to hear on the pricing. I have heard these screens run upwards of $2000 (which is pretty ridiculous). But since there really aren't that many choices out there, I guess I'll pay it.

------------------
Barry
bnewton is offline  
post #6 of 18 Old 03-30-2001, 07:42 AM
AVS Special Member
 
DMan's Avatar
 
Join Date: Feb 1999
Location: Atlanta, GA, USA
Posts: 1,585
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
<font face="Verdana, Arial" size="2">I have heard these screens run upwards of $2000 (which is pretty ridiculous). But since there really aren't that many choices out there, I guess I'll pay it.</font>
Yes, but for that price you get...incredible customer service, a custom built screen just for you, unbelievable care in packagaing, fit and finish that are second to none, and a screen surface that disappears when you start watching a movie.

Many times people spend several thousands of dollars on a front projector and then want to skimp on the screen. I can't emphasis enough the importance that a good screen makes. Afterall, it's the only piece of HT equipment that you watch during a movie.



------------------
DMan
The Academy Home Theater
DMan is offline  
post #7 of 18 Old 03-30-2001, 08:24 AM
Member
 
randmac's Avatar
 
Join Date: Oct 2000
Location: Long Beach, CA, USA
Posts: 111
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I believe Stewart recommends 10" - 12" between the speaker and the microperf screen for optimum sound. If your install is tight, try to get at least 4". I will be using in-wall speakers with screen 5.25" from the wall.

Be prepared, microperfing a screen adds a significant cost to the screen!

------------------
Randy
G20/CI
randmac is offline  
post #8 of 18 Old 04-02-2001, 08:24 AM
Member
 
bnewton's Avatar
 
Join Date: Feb 2001
Location: Norcross, GA
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Well, I got my quote. Without revealing exact numbers, let's just say that if it had been only $2000, I would have been much happier. The actual price is about 10% of my entire theater construction budget.

Sheesh! I guess I'll get out my credit card...

------------------
Barry
bnewton is offline  
post #9 of 18 Old 04-02-2001, 09:35 PM
Advanced Member
 
ClaudeD's Avatar
 
Join Date: Jun 1999
Location: Short Hills, New Jersey
Posts: 778
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Barry,

I was shocked too when I discovered how much perforations added to the cost. I spoke to Don Stewart about it, and he indicated that amortizing the extraordinary purchase price and maintenance of the "perforater machine" over the limited number of screens was the reason.

I'm sure that they make a reasonable profit also, but I haven't encountered a company that more deserves to make a profit. Their service is absolutely first-rate and so are their products.

It's too bad you'll have to go to plastic for this, but in the end it will be worth it.

Claude
ClaudeD is offline  
post #10 of 18 Old 04-03-2001, 09:18 PM
Advanced Member
 
KFung's Avatar
 
Join Date: Apr 2000
Location: Ottawa, Ontario, Canada
Posts: 879
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Barry,

Yeah the micro-perf is REALLY expensive (something 2x the regular screen), as Claude said the manufacturing of it is pretty expensive. I remember Don Stewart saying to Peter/Panaramax at CES that the matched punches cost something like $100k! I think that price also includes an equalizer for the centre channel behing the screen.

Regards,

Kam Fung

[This message has been edited by KFung (edited 04-04-2001).]
KFung is offline  
post #11 of 18 Old 04-04-2001, 09:19 PM
REW
AVS Special Member
 
REW's Avatar
 
Join Date: May 1999
Location: Silicon Valley North(Canada)
Posts: 1,299
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 10
Kam,
I know you like 10ft wide microperf.Curious to hear price of this in$CDN.
http://www.avsforum.com/ubb/smile.gif

------------------
Ron
"Your priorities will be different-its the weighting that counts!"

Ron
"Your priorities will be different-its the weighting that counts!-only if its done by FET!"

REW is offline  
post #12 of 18 Old 04-05-2001, 08:52 PM
AVS Addicted Member
 
CINERAMAX's Avatar
 
Join Date: Sep 2000
Location: From Coconut Grove FL to the rest of the globe with TLC.
Posts: 12,718
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Liked: 71
Kam, REW:

I do not know exactly how much the screen cost. I can find out. But for you guys, or KGB, the Stewart equaliser can be had for free from me.

Kam I was back in VEGAS last weekend.I saw the 3-d 14-16' by 9' TORUSSes on M&M world and RACE for ATLANTIS. They were silver colored and SUCKED BIG TIME LIKE MY SILVER TORUS install. The TORUSSES must be WHITE, forget the Grey it wont work. I think.
CINERAMAX is offline  
post #13 of 18 Old 04-06-2001, 06:59 AM
Member
 
bnewton's Avatar
 
Join Date: Feb 2001
Location: Norcross, GA
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
So you are giving away these equalizers? What gives? Since the price seems right, I would be interested if Stewart will give me a break if I don't need theirs.



------------------
Barry
bnewton is offline  
post #14 of 18 Old 04-06-2001, 12:22 PM
AVS Addicted Member
 
CINERAMAX's Avatar
 
Join Date: Sep 2000
Location: From Coconut Grove FL to the rest of the globe with TLC.
Posts: 12,718
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Liked: 71
I guess? If you send me 30 bucks I'll 2nd day it to you, and have dinner with the change.

It is new in the box and has a separate power supply. I don't know if stewart will deduct though.
CINERAMAX is offline  
post #15 of 18 Old 04-06-2001, 12:45 PM
Member
 
bnewton's Avatar
 
Join Date: Feb 2001
Location: Norcross, GA
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Okay, I'm checking with Stewart, so I'll let you know Monday. I'm still in "sticker shock" on this screen, so hopefully they will be willing to deduct the price of the equalizer.

How is it you ended up with an extra one of these?



------------------
Barry
http://www.newton.org/theater.html
bnewton is offline  
post #16 of 18 Old 04-06-2001, 10:47 PM
Advanced Member
 
KFung's Avatar
 
Join Date: Apr 2000
Location: Ottawa, Ontario, Canada
Posts: 879
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Peter,

I don't know, I think grey is feasible. The silver is colour shifting the image because of the metal platelets in the mix (they have their own colour that affects the image), a proper grey paint should not (I can't imagine Stewart not mixing their gray properly).

Ron,

I have no idea what is costs, but probably $4k+...

Regards,

Kam Fung
KFung is offline  
post #17 of 18 Old 04-06-2001, 11:36 PM
AVS Addicted Member
 
CINERAMAX's Avatar
 
Join Date: Sep 2000
Location: From Coconut Grove FL to the rest of the globe with TLC.
Posts: 12,718
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Liked: 71
I used to install Meridian Digital speakers back then...You cannot insert the eq into the center channel circuit.

Kam , True. After some thought you may be right, the problem becomes that the high gain coat will become more silvery as you increase the gain. Not?
CINERAMAX is offline  
post #18 of 18 Old 04-07-2001, 06:14 PM
Advanced Member
 
KFung's Avatar
 
Join Date: Apr 2000
Location: Ottawa, Ontario, Canada
Posts: 879
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Peter,

I guess the Meridian's could do their own EQ with no loss, since they are all-digital...

As for the screen, I would think that it would depend on when they shift from the optical coating (whatever it's made of) they use in the lower gain screens like the 1.3 and 1.5 to a mix of paint with metal platelets in it. Don Stewart would probably know best...

Regards,

Kam Fung
KFung is offline  
Closed Thread Screens

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off