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MOON

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I will try tilting the speakers a bit forward and see what happens. The panels are now level. I will also try moving the listening chairs back a bit.The speakers are very close to 5ft off the back wall which is good. The 21 inches off the side wall is all I can manage due to the width of the room.

About the forward tilt, what differences would that make from having the panel level?
 

JonFo

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Moon, is this your current setup?

attachment.php


If so, you definitely need additional broadband absorption behind your speakers and long the side walls behind the speakers.
The points of any front wall -> side wall -> listener bounce should also be treated with devices that handle 300 ~ 400Hz on up (lower is better).

While the center spot in a well setup ML rig will always be the 'best' it should not be radically different than a few feet L or R.

This is one of the reasons I went with the big center, as running stereo processed with the Meridian TriField mode (7.1 in my rig) yields a very wide and coherent soundstage. Having the center channel anchor the sound is very effective in delivering a wider 'sweet spot'.
Of course the middle spot is always the best, but not by a whole bunch.

But even with that center, the system has improved dramatically by correctly treating the front wall and the rest of the room.

Moon, the rest of your room seems in good shape. It’s mostly the front wall and rear wave management that I’d focus on for now.
 

kach22i

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Moon, is this your current setup?
Dang, Houston we have a problem if that is his room.

All of the things people have been saying apply to this room. That reflective window shade might be 75% of the problem. The other 25% might be what is directly behind your head, should be non-reflective as well.
 

kach22i

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How about this? It's really dead! :devil:
That's not dead acoustically plus it smells.

I have heard systems when a cat or a dog walking around the room changes the sound slightly.

My wife, well I better not say, she might be reading this.:D

I need a dedicated listening room with a lock on the door.:cool:
 

C.A.P

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Oh boy get that window covered up . They are a sucubus for image and detail . Windows fireplaces and any depresion will totoly play with the center image. I know I am fighting a fireplace now. I will be making a full plug that is functional and looks good in the near future. Over all your room set up looks decent. The space between them is nice, Make sure to sit back at least double the distance from inside edge to edge. Change chair heights too.
 

beefchowmein

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since we're talking about speaker placement and acoustic reflection. Does anyone know if a projector screen makes a bad acoustic reflection/damping material? I have a screen right in the middle between the two speaker. I see this on a lot of member's setup. Would this affect the soundstage?
 

JonFo

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since we're talking about speaker placement and acoustic reflection. Does anyone know if a projector screen makes a bad acoustic reflection/damping material? I have a screen right in the middle between the two speaker. I see this on a lot of member's setup. Would this affect the soundstage?

Non Acoustically transparent screens are indeed reflective, and not just of light ;)

So yes, they will be somewhat of an issue, but mostly for the sound from the rear speakers.
It should have very little effect on the fronts, other than to nullify and rear wave reflections from the front wall, which is actually a good thing.

Ideally, an ML home theater rig should have a screen wall across the front. That is, a wall made up of acoustically transparent cloth between the walls and the screen, an acoustically transparent screen (SMX, ScreenPix2 or Microperf2).
The wall and sides behind the screen wall are totally treated with broad range absorbers. The center channel is mounted smack in the middle of the screen. Ideally, an equal unit to the L/R pair.
 

MOON

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Hi Johnathan,

Sorry for the late reply. Yes , that picture is my new dedicated sound room. I moved the chairs back to 12 ft from the speakers and that improved the area for the soundstage.

When you mentioned absorbtion behind the speakers, I assume it's a given you are talking about the Real Trap HF Mini trap directly behind each logan. As you can see in the picture , I have treated the 1st and 2nd reflection points. I had to put the treatment at the 1st reflection horizontally due to the side window. Question - When you said additional absorbtion to the side of the speaker, where were you referring to specifically ? Do you mean on the side walls behind the speaker in addition to the 1st and 2nd reflection points and HF mini's behind each speaker? You can see in the picture that I already have ASC 1/4 round tube traps in both corners behind the speakers.

I was wondering about projector screens as well, since I will be putting one in.I see Stewart makes a screen, I beleive it's micro perf which lets the sound pass through it. Would you recommend this type of screen? My screen will be 2 ft to the rear of the panel and will take in the distance between the speakers, approx 75 inches , inside to inside rail.Since I plan to get the HF mini's to take care of the rear wave, what is the point on getting a sonically transparent screen anyway?

Thanks guys for the advice. The blinds have to stay. They were kind of pricey. I tried to drywall right over that window behind the stereo , but my better half put the kybosh on that one. Anything else , I can do anything ( treatments, etc. ) in the room except drywall over windows. lol

Cheers, Greg
 
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Craig

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There should be no need to add any forward tilt to your speakers. You have the Odysseys and they are already perpendicular to the floor. The Vantages and especially the Summits have quite a rearward rake.
 

kach22i

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There should be no need to add any forward tilt to your speakers. You have the Odysseys and they are already perpendicular to the floor. The Vantages and especially the Summits have quite a rearward rake.
I did not know this starting out this thread.

I wonder if they found a lot of people even in high-end stores first impression of the speaker was walking in the room and standing......which lead to the tilt?

I can't see a lot of other reason for it, unless M/L relies on a good first reflection off the ceiling to give the speaker a little more air.
 

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[Regarding Tilt...] I did not know this starting out this thread.

I wonder if they found a lot of people even in high-end stores first impression of the speaker was walking in the room and standing......which lead to the tilt?

I can't see a lot of other reason for it, unless M/L relies on a good first reflection off the ceiling to give the speaker a little more air.

Nope, it has to do with two things: First - shipping and packaging. The older 70+ inch tall units required freight shipping and much larger boxes.

Second, they were 70+ inches tall and dominate any room they are put in.
So part of the reason is aesthetics, they wanted a smaller profile, both in height and in width. Note that the current top of the line (summit) is about the size of the old SL3, which itself was an already shrunk Sequel.

As for demo's standing up, the taller speakers actually work very well unless you are 6'3" or taller.

Personally, I’m a big fan of the panels being A) perfectly vertical and B) top of panel is ~72” from floor, as I think from a purely performance standpoint, those are ideal attributes.
 

Nielsen

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I will be honest, I would take that windowframe out, and cover the window with plywood, making it a nice rear wall, but thats just me.
Second, looking at your room I think you may want to experiment with some serious diffusors behind the speakers.
A guy with Summitts have these behind his speakers : http://www.diffusor.com/Diffusorpaneler.htm Its a swedish page, but other companies have similar products, though not in wood maybe.
JonFo wrote to you about absorbtion behind the panels, maybe thats what you need instead in your room, you can experiment with some things untill you know what you need.
Also, if you can, try and read the article from Stereophile regarding the test of SL3, here they make the speaker sing. Here they dampened the back wave from the speaker with traps.
I just write this since you have a dedicated room for your stereo, I could never install any of this in my livingroom, except maybe for diffusors painted in the same color as the wall.
 
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Bernard

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I tried to drywall right over that window behind the stereo , but my better half put the kybosh on that one. Anything else , I can do anything ( treatments, etc. ) in the room except drywall over windows. lol

Cheers, Greg
How about drywalling over the window and then painting in the window and blinds ? Treat your better half to a day at the spa; when she gets back it will be done, and she won't notice. :devil:
 
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MOON

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Bernard, you have given me a good laugh. Love your idea.
Jonathon, I asked you a couple of questions about treatments on the end of the previous page and a question about pj screens . Can you give me some feedback on those questions.

Benard, I don't think my artistry skills are up to snuff to fly with your original idea.

Thanks , greg
 

Nielsen

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Explain to your wife that a Stewart pulldown screen costs mega bucks, a screen mounted in a solid frame on the back wall is the best option. (dont say to her the window will be covered)
You can cover the screen with velvet curtains, remote controlled.
 

JonFo

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Hi Johnathan,

Sorry for the late reply. Yes , that picture is my new dedicated sound room. I moved the chairs back to 12 ft from the speakers and that improved the area for the soundstage.
Hi Greg, apologies, I missed this post a few days ago. So here goes...
When you mentioned absorption behind the speakers, I assume it's a given you are talking about the Real Trap HF Mini trap directly behind each logan. As you can see in the picture , I have treated the 1st and 2nd reflection points. I had to put the treatment at the 1st reflection horizontally due to the side window. Question - When you said additional absorbtion to the side of the speaker, where were you referring to specifically ? Do you mean on the side walls behind the speaker in addition to the 1st and 2nd reflection points and HF mini's behind each speaker? You can see in the picture that I already have ASC 1/4 round tube traps in both corners behind the speakers.
The front reflection point seems well treated, but I believe that when it comes to the ‘soundstage’ or sweet spot, the rear wave reflection points are just as critical.
What we are trying to do is ensure that the rear wave arrives both late enough (>15ms relative to front) and low enough (<12dB relative to front) to not mess up the clarity of the front wave.

We usually manage the ‘late enough’ part by pulling the speakers out into the room, which lengthens the rear wave travel time. But some rooms don’t support getting to the 15ms threshold.
So we absolutely need to do the ‘low enough’ by dampening the rear wave. It is also important to dampen the rear to reduce reflections that might go back through the panel directly and generate comb filtering.
When I say to the side of the speakers, I mean directly to the side or maybe even slightly behind them on the side walls. What you are treating is the reflection point from the rear wave bouncing off the front wall onto that point on the side wall.

Now, if you treat the front wall with a MiniTrap HF, then it’s no longer as critical to treat the side wall next to or behind the speakers, as the rear wave will be dampened enough by the MiniTrap. But it never hurts to try some treatment on the sides, mostly because additional absorption at the mid-bass ranges (150Hz to 300Hz), is a positive with dipoles (that out-of phase rear wave will cancel the front at those freq.). So at least a Minitrap sized unit should go there IMHO.

So to sum up: Place a MiniTrap HF in line with the direct path from the rear panel (which is slightly off-set on the wall due to the speaker toe-in). Optionally, place a minitrap on the side wall just behind the speakers.
In your room, that would mean abutted against the ASC quarter round trap you already have on both the rear and side walls. The Minitraps would be offset from the wall at least 2+ inches for optimum low-frequency absorption.

I was wondering about projector screens as well, since I will be putting one in.I see Stewart makes a screen, I beleive it's micro perf which lets the sound pass through it. Would you recommend this type of screen? My screen will be 2 ft to the rear of the panel and will take in the distance between the speakers, approx 75 inches , inside to inside rail.Since I plan to get the HF mini's to take care of the rear wave, what is the point on getting a sonically transparent screen anyway?

Greg, the main reason for a sonically transparent screen is you can put the center channel directly behind it at the correct height.
In your case, that would be on a shelf added to your rack right above the CDP.
Looks like you would need to build up both the rack towers to support a Stage (which is the only model of center I’d recommend for the mid-sized ML’s and larger).

The wall right behind the racks would be treated with two more MiniTrap HF’s mounted vertically side by side, with their tops aligned at the bottom edge of the window (ensuring the entire height of the center is covered).

A Stewart Microperf2 roll down would work nicely there. The newer MicroPerf2 screens are truly acoustically transparent, as is the ScreenPix2 material from ScreenResearch labs. All they do is drop the center level 1dB, which you compensate for in the processor.
These are not cheap, but are a must for correct dialog localization and balanced audio across the front.

Warning though: If the screen will be covering equipment in the rack that has lights or is overly reflective, then you will see them through a microperf screen. Even a non-perfed screen will have problems with light behind it.



Thanks guys for the advice. The blinds have to stay. They were kind of pricey. I tried to drywall right over that window behind the stereo , but my better half put the kybosh on that one. Anything else , I can do anything ( treatments, etc. ) in the room except drywall over windows. lol

Cheers, Greg

OK, I took you at your word Greg, and gave you a pretty long list of ‘anything else’, hope it passes the design committee (never mind the finance committee) ;)
 
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Nielsen

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Here is a link to the SL3 test in Stereophile, with Bruce Brissons work. Interesting I think :
http://stereophile.com/floorloudspeakers/145/index6.html

Especially this is funny :

When Gayle walked in the next morning and saw the grove of Traps surrounding his speakers, he took a long, slow saunter around them, examining the setup with a sardonic smile. He shot a challenging look at Bruce and sat down in the sweet spot. Seconds after the music began to play, he leapt up and checked each Trap's placement very carefully. Then he demanded, "Take 'em all out and show me what you did!" So we started all over.
 

benleeys

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Here is a link to the SL3 test in Stereophile, with Bruce Brissons work. Interesting I think :
http://stereophile.com/floorloudspeakers/145/index6.html

Thanks for the link, Nielsen. Interesting review. I see that Wes Phillips is another believer in bi-wiring. I quote -

Don't hesitate—bi-wire the SL3, even if it means you must use less expensive speaker cables. I don't know whether or not the woofer's back EMF interferes with the "unusually revealing" electrostatic element, as Sanders claims. But I do know that the difference between running the SL3 with a single run and a double run of cable is not subtle. Bi-wiring results in huge gains in clarity, detail, and grace.
 

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