Acoustical Treatments Master Thread - Page 415 - AVS Forum | Home Theater Discussions And Reviews
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post #12421 of 12454 Old 06-03-2019, 09:27 AM
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Originally Posted by harrisu View Post
This made me thin that the difference I'm hearing b/w surround vs front stage is because of how front stage b/w MLP and screen is all covered with black velvet is absorbing high frequencies.
Have you tried turning the treble knob to boost the high frequencies to compensate for them being absorbed by the black velvet?
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What about Center? We leave center reflection completely open on side wall and only cover contra-lateral reflections for side speakers?
ALL the research I have read concluded that early reflections aid in speech intelligibility, so I don't absorb the side wall first reflections of the Centre speaker. However, it is worth putting absorption on the front wall because those reflections come from the same direction as the L/C/R speakers and can muddy the critical front soundstage. The only other place I would put absorption is the middle of the back wall (directly opposite the Centre speaker).
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Also what would you recommend for ceiling treatment?
Absorption or diffusion, whatever sounds better to you (as long as it reduces the hard reflection).

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post #12422 of 12454 Old 06-03-2019, 10:51 AM
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Originally Posted by sdurani View Post
Have you tried turning the treble knob to boost the high frequencies to compensate for them being absorbed by the black velvet?
I use Dirac which uses a curve to determine how the FR needs to look like up to 20K Hz. When I take FR after Dirac is all set and done, I do get up to 18K like 3dB less than 100Hz. That's exactly how the the curve looks like in Dirac and FR in Rew confirms it. Does this mean that Dirac is taking care of high frequencies being absorbed by Black Velvet by boosting them? I can post pre/post FR if that helps?

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ALL the research I have read concluded that early reflections aid in speech intelligibility, so I don't absorb the side wall first reflections of the Centre speaker. However, it is worth putting absorption on the front wall because those reflections come from the same direction as the L/C/R speakers and can muddy the critical front soundstage. The only other place I would put absorption is the middle of the back wall (directly opposite the Centre speaker).
Ok so you have nothing on side walls to absorb. May be to diffuse to create bigger sound stage? I see many HT of the month and many are designed by Nyel and he uses many diffusers on side/back/celing. He also uses some absorption panels but mostly diffusers.

Absorption or diffusion, whatever sounds better to you (as long as it reduces the hard reflection).[/QUOTE]
Sorry, What's hard reflection?
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post #12423 of 12454 Old 06-03-2019, 10:59 AM
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Originally Posted by harrisu View Post
Does this mean that Dirac is taking care of high frequencies being absorbed by Black Velvet by boosting them?
Dunno, I was simply suggesting you do it by ear (increase the treble until it sounds right to you). Nothing more complicated than that.
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What's hard reflection?
A reflection with nothing (diffusion, absorption, furniture, etc) to soften it.

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post #12424 of 12454 Old 06-03-2019, 11:20 AM
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Originally Posted by sdurani View Post
Dunno, I was simply suggesting you do it by ear (increase the treble until it sounds right to you). Nothing more complicated than that. A reflection with nothing (diffusion, absorption, furniture, etc) to soften it.
Thx. I don't know if it has to do with more Treble. It has more to do with spaciousness. I can hear the diff b/w surround/surround back VS front stage and that front stage sounds a bit further away from back. But as you and many here at the beginning of thread pointed out that for multi channel front wall should be fully treated. I don't have it fully treated so many be its a good idea to do that. Plus I think I'm going to remove the absorpion panels from side and ceiling walls and then put them on front fall to see how it sounds.

As I was reading the beginning of this tread, there seemed to be conflicts about how far the diffuser can be placed. Someone said 10 feet and some said it doesn't matter. I placed mine 65" away and seemed to do a good job even though its only 1 24"x24" diffuser on each side of back wall.
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post #12425 of 12454 Old 06-03-2019, 11:37 AM
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Originally Posted by harrisu View Post
I don't know if it has to do with more Treble. It has more to do with spaciousness.
You said "black velvet is absorbing high frequencies", so I was suggesting one way of restoring them. If the problem is not longer a lack of high frequencies, then ignore my earlier suggestion (no longer applies).

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post #12426 of 12454 Old 06-03-2019, 01:39 PM
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You said "black velvet is absorbing high frequencies", so I was suggesting one way of restoring them. If the problem is not longer a lack of high frequencies, then ignore my earlier suggestion (no longer applies).
Yeah it will be a bit of trial and error kind of approach. I LOVE LOVE LOVE what black velvet does to the image quality. Using JVC RS500 calibrated on a 130" 2.40 screen with 1.3 gain perf really pops the image with black velvet all around. Not as good as OLED but gets very close. Letting go of it will be a sad moment and I"ll have to see how much to compromise to get that sound I'm after.
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post #12427 of 12454 Old 06-03-2019, 01:54 PM
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Originally Posted by harrisu View Post
I LOVE LOVE LOVE what black velvet does to the image quality. Using JVC RS500 calibrated on a 130" 2.40 screen with 1.3 gain perf really pops the image with black velvet all around. Not as good as OLED but gets very close. Letting go of it will be a sad moment and I"ll have to see how much to compromise to get that sound I'm after.
You could also (temporarily?) Add something in front of the velvet at the reflection points (like a diffuser) and see if that creates the space you're after.
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post #12428 of 12454 Old 06-03-2019, 01:59 PM
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You could also (temporarily?) Add something in front of the velvet at the reflection points (like a diffuser) and see if that creates the space you're after.
Thumbs up. Will try that. Has anyone here tried anything other than Black Velvet that's AT? The closest stuff I have found is Mellotone from Part Express https://www.parts-express.com/mellot...QaAugMEALw_wcB

I haven't tried it but I'm very sure its not as black as Black Velvet.
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post #12429 of 12454 Old 06-04-2019, 10:45 AM
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@sdurani , @HopefulFred , I did an experiment yesterday based on what I read on 1st five pages of this thread. The general agreement seemed to be to have a dead front wall in a multi channel room. So I did that. I placed 4" thick 703 Rockwool covering the front wall from year to top. Then b/w MLP, I only had one 1 panel on each side wall and back wall with 1 diffuser on each side L/R. Did the calibration and when I did the listening, it felt dead. All the high frequencies were like gone and room had no spaciousness. Now it could be because I have all the walls b/w MLP and screen covered by black velvet. Then I removed most of the panels from front wall and left only 3 in place (1 in the middle and 1 behind Left and 1 behind Right speaker). This brought back the spaciousness.

But this brings an interesting question. Most likely, the deadness is because of black velvet. So I have 2 options.

1 - Cover front wall completely and remove the black velvet to the point where it brings spaciousness.
2 - Don't cover the front wall completely and only do to the point where it doesn't take spaciousness away.

In both cases, I would end up with spaciousness but for some reason, option 1 is very much encouraged at least in first 5 pages that I read up to. My question is which one is better and why even when they both provide spaciousness?

Thx.

Last edited by harrisu; 06-04-2019 at 02:18 PM.
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post #12430 of 12454 Old 06-04-2019, 02:58 PM
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Originally Posted by harrisu View Post
...I removed most of the panels from front wall and left only 3 in place (1 in the middle and 1 behind Left and 1 behind Right speaker). This brought back the spaciousness.

But this brings an interesting question. Most likely, the deadness is because of black velvet. So I have 2 options.

1 - Cover front wall completely and remove the black velvet to the point where it brings spaciousness.
2 - Don't cover the front wall completely and only do to the point where it doesn't take spaciousness away.

In both cases, I would end up with spaciousness but for some reason, option 1 is very much encouraged at least in first 5 pages that I read up to. My question is which one is better and why even when they both provide spaciousness?

Thx.
We probably need to know what kind of speakers you are using; what's the toe-in status of them; and how far from the walls (front and side) are they. Stereo imaging and and spaciousness are pretty strongly influenced by those factors - because most of the "space" is supposed to be in the recording already. If you are preserving those details in playback, it should there, IMO.

Beyond that, I would say that there may be some ambiguity in what exactly you're hearing and maybe the extra high-frequency reverberance is detracting from other aspects of fidelity when it comes from the screen wall - when you remove most of the screen wall absorption. (obviously I don't know what you're hearing...) I think the best science suggests the it's lateral reflections (first reflection on the same side as the sound source) that are best for widening stereo images - and that's usually what people find most pleasing.
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post #12431 of 12454 Old 06-05-2019, 01:28 PM
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Originally Posted by HopefulFred View Post
We probably need to know what kind of speakers you are using; what's the toe-in status of them; and how far from the walls (front and side) are they. Stereo imaging and and spaciousness are pretty strongly influenced by those factors - because most of the "space" is supposed to be in the recording already. If you are preserving those details in playback, it should there, IMO.

Beyond that, I would say that there may be some ambiguity in what exactly you're hearing and maybe the extra high-frequency reverberance is detracting from other aspects of fidelity when it comes from the screen wall - when you remove most of the screen wall absorption. (obviously I don't know what you're hearing...) I think the best science suggests the it's lateral reflections (first reflection on the same side as the sound source) that are best for widening stereo images - and that's usually what people find most pleasing.
Sure. I am JBL 4722N as L/C/R and JBL SCS-8 as Surr/SurrBack/Atmos. All together its a 7.2.4 system in a completely sealed room. I had to place one sub on the front which moved Right speaker to very close to side wall. So had to toe it in aggressively. Matched Left speaker accordingly. L/C/R are only 4" off the back wall and I have 4" 703 from ear to ceiling.

I did a little interesting experiment. I was always curious as to how much black velvet absorbs. So I took two of the panel that are covered with black velvet and took out the foam from inside it. Then placed them where I could hear echo when I clapped my hands. After I placed these panels (again no foam inside the panels), and clapped, the echo was gone. This clearly shows that just the black velvet itself was absorbing high frequencies. Clearly having black velvet all around the area B/w MLP and screen was absorbing all the high frequencies. Since I didn't have front wall completely covered, I was still getting some sense of spaciousness because of the sound wave that were moving back and forth (not from side walls). As soon as I covered the front wall, that spaciousness disappeared. So once I realized what black velvet is doing, I took out 2 panels from side walls (have 3 panels on from each side) and 1 from ceiling and tried it out and there it is again. I could hear much better spaciousness when they are removed. Very clear that Black Velvet is absorbing a lot of high frequencies.

So now I have 2 options and need to know the pros and cons
1 - Remove black velvet from side wall and ceiling.
Pros: More options available like installing diffusers.
Cons: Impacts the video quality since light will reflect off the side/ceiling walls.
2 - Keep black velvet as is and remove the treatments from front wall.
Pros: Great video quality
Cons: I do get spaciousness but need to know if its good enough????? What are the drawbacks of having reflection coming from front wall. Also can't install diffusers on side/celing.
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post #12432 of 12454 Old 06-05-2019, 04:44 PM
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Crosspost from my build thread as I thought I may get some help here.



OK. so I feel like I have called every HVAC supply house in the Tri-State area looking for Linacoustic RC and have come up short. It seems like everyone carries the Owens Corning Quieter duct liner and that's what was recommended as a equivalent. I was planning to follow BIG's method of two 1" layers with plastic sheeting in between them behind my screen wall. Has anyone used this product? Looking at the cut sheets, it seems to be very similar, and the OC may have slightly better performance. It comes in the same 1"x48"x100' roll that Linacoustic comes in and I can get a roll for just under $300 out the door. More information attached.


I did some searching and found one or two mentions of this OC duct liner, but nothing definitive on if it is really an alternative.


If I do get a roll I will have some left over. Could I build up the corners to ~6" thick and make effective bass traps? Could I use this instead of OC703 to make acoustic panels?

What are your thoughts?

Thank you for your help!
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7.1.4 Theater Room (In Progress): JVC-RS46U, Silver Ticket AT 2.35:1 142”, Onkyo RZ830, Anthem PVA-7, Panasonic DBT-110, JBL Studio 270’s, 4 - 15" DIY Sealed Subs

3.1 Living Room: Samsung 64” F8500 Plasma, Anthem MRX 300, Dynaudio Audience 52’s, Dynaudio Audience 122C, NHT SubOne
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post #12433 of 12454 Old 06-06-2019, 06:45 AM
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Originally Posted by Mocs123 View Post
Crosspost from my build thread as I thought I may get some help here.



OK. so I feel like I have called every HVAC supply house in the Tri-State area looking for Linacoustic RC and have come up short. It seems like everyone carries the Owens Corning Quieter duct liner and that's what was recommended as a equivalent. I was planning to follow BIG's method of two 1" layers with plastic sheeting in between them behind my screen wall. Has anyone used this product? Looking at the cut sheets, it seems to be very similar, and the OC may have slightly better performance. It comes in the same 1"x48"x100' roll that Linacoustic comes in and I can get a roll for just under $300 out the door. More information attached.


I did some searching and found one or two mentions of this OC duct liner, but nothing definitive on if it is really an alternative.


If I do get a roll I will have some left over. Could I build up the corners to ~6" thick and make effective bass traps? Could I use this instead of OC703 to make acoustic panels?

What are your thoughts?

Thank you for your help!
Have you tried Insulation Supply Co. in Nashville? www.insulationsupplycompanynashville.com

I went there a couple days ago and bought some Thermafiber panels. They have OC 703 and Thermafiber in a lot of different thicknesses, including 1 1/2 inch, which I hadn't seen anywhere. They have other stuff, too, but I was excited to find these locally.
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post #12434 of 12454 Old 06-06-2019, 03:11 PM
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Originally Posted by sdurani View Post
........ ALL the research I have read concluded that early reflections aid in speech intelligibility, .....
This conclusion is regarding enviornments that are noisy. In noisy enviornmenta, early reflections act like reinforcement to direct sound which improves signal to noise (voice SPL / ambient noise) ratio.

Home theaters are not noisy enviornments so this "early reflections aid in speech intelligibility" conclusion does not apply.

Ref page 8 of
https://www.jblpro.com/pub/technote/spch_intl_1.pdf
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post #12435 of 12454 Old 06-06-2019, 04:11 PM
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Home theaters are not noisy enviornments...
But movie soundtracks are. My comment regarding speech intelligibility was not about having a conversation in a home theatre but hearing dialogue in a movie. The soundtrack is the environment.

"Early reflections improve speech intelligibility"
- Floyd Toole, Loudspeakers & Rooms: http://www.wghwoodworking.com/audio/...production.pdf

"There seems to be consensus in the field that some early reflections actually help make speech more intelligible."
- Mathas Johansson, Dirac white paper: http://diracdocs.com/on_room_correction.pdf

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post #12436 of 12454 Old 06-07-2019, 09:48 AM
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@sdurani + others, I think I have finally found the solution of my problem with black velvet absorbing high frequencies. I wrote it down in Black out thread here https://www.avsforum.com/forum/24-di...l#post58153242

To summarize it: I realized that black velvet was absorbing too much of high frequencies. I still had spaciousness in my room but that was because I didn't have front/back walls treated and sound was bouncing back and forth b/w front and back and provided some spaciousness. After reading up, I realized that front wall should be absorbing everything. I made the change and room became dead . Only way I could make it sound spacious was to remove black velvet but that was taking image quality away. Had to come up with something.

Solution: I took the panels from side walls and punched holes in it using meat thermometer. It as a sharp tip and gets thicker after that. It was thick enough to punch large enough hole that is not visible to eyes. Then I glued FRK paper with its reflective side facing the room. Did that to 2 panels on each side wall and to one panel on ceiling. Tried it out and it sounded much better. I had to remove one velvet piece completely from ceiling that was closed to MLP in center. After I removed it, the room sounded very spacious. I kinda made black velvet reflective . To some it might not be the perfect solution but based on my listening sessions of 1 hour, I found the sound spacious enough. Plus if I want some more, I can do the same to other panels that are just sitting there empty wrapped in black velvet. This basically allows me to control how much of 1st reflection I want. Please note that I have the front wall treated now with 4" 703 from ear up to ceiling. I can't cover below ear because my speakers are BIG. JBL 4722N with dimention of (49.9 x 30 x 17.75in) http://www.jblpro.com/www/products/c...n#.XPqU8W66Obg. After having 1 Mini marty sitting b/w Center and Right channel, there really isn't much space left.

What do you guys think of my approach. Based on purely how it sounds, well it sounds good so far Will do more testing later.
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post #12437 of 12454 Old 06-07-2019, 10:08 AM
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Originally Posted by harrisu View Post
@sdurani + others, I think I have finally found the solution of my problem with black velvet absorbing high frequencies. I wrote it down in Black out thread here https://www.avsforum.com/forum/24-di...l#post58153242

To summarize it: I realized that black velvet was absorbing too much of high frequencies. I still had spaciousness in my room but that was because I didn't have front/back walls treated and sound was bouncing back and forth b/w front and back and provided some spaciousness. After reading up, I realized that front wall should be absorbing everything. I made the change and room became dead . Only way I could make it sound spacious was to remove black velvet but that was taking image quality away. Had to come up with something.

Solution: I took the panels from side walls and punched holes in it using meat thermometer. It as a sharp tip and gets thicker after that. It was thick enough to punch large enough hole that is not visible to eyes. Then I glued FRK paper with its reflective side facing the room. Did that to 2 panels on each side wall and to one panel on ceiling. Tried it out and it sounded much better. I had to remove one velvet piece completely from ceiling that was closed to MLP in center. After I removed it, the room sounded very spacious. I kinda made black velvet reflective . To some it might not be the perfect solution but based on my listening sessions of 1 hour, I found the sound spacious enough. Plus if I want some more, I can do the same to other panels that are just sitting there empty wrapped in black velvet. This basically allows me to control how much of 1st reflection I want. Please note that I have the front wall treated now with 4" 703 from ear up to ceiling. I can't cover below ear because my speakers are BIG. JBL 4722N with dimention of (49.9 x 30 x 17.75in) http://www.jblpro.com/www/products/c...n#.XPqU8W66Obg. After having 1 Mini marty sitting b/w Center and Right channel, there really isn't much space left.

What do you guys think of my approach. Based on purely how it sounds, well it sounds good so far Will do more testing later.
I know you say you can't treat front wall below ear level. You should def treat it to combat sbir issues though. If room sounds dead just use diffusion so it only absorb low freq while retain high frequencies.

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post #12438 of 12454 Old 06-07-2019, 11:09 AM
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I know you say you can't treat front wall below ear level. You should def treat it to combat sbir issues though. If room sounds dead just use diffusion so it only absorb low freq while retain high frequencies.
sory how do I def treat? I don't even know what this means . The room was dead because of the usage of black velvet. If I use diffuser, black velvet has to go away which impacts the image quality. I was trying to find a solution that can allow me to leave black velvet in place. I'm sure Diffuser will make the room sound even better if they are placed b/w MLP and screen but that'd require that I remove the black velvets. I do have 2 diffuser on back back each 65" away from MLP on left and right sides of back wall.
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post #12439 of 12454 Old 06-07-2019, 02:38 PM
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Originally Posted by harrisu View Post
sory how do I def treat? I don't even know what this means . The room was dead because of the usage of black velvet. If I use diffuser, black velvet has to go away which impacts the image quality. I was trying to find a solution that can allow me to leave black velvet in place. I'm sure Diffuser will make the room sound even better if they are placed b/w MLP and screen but that'd require that I remove the black velvets. I do have 2 diffuser on back back each 65" away from MLP on left and right sides of back wall.
Def = Definitely

I was talking about your front wall from ear level to floor behind speakers. While you won't see them due to AT screen and such, it will help bright/live up your room since high end freq will scatter rather than fully absorb. You can also do that on rear wall as well. I was recommending it since your side walls were absorbing all highs so if you bright up some other parts of the walls where you can't see then it will balance itself out.

As far as diffusion on side walls, you can still use wood slats on top of absorption panels but cover it with GOM black fabric over the whole panel. That pretty much will live up your room. I believe its darker than speaker cloth and shouldn't be noticeable on side walls.

Or you could add more bass traps with scatter plates or tune membrane to absorb more lows and it will balance it to where highs don't seem overdamped. Different ways to skin the cat.

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post #12440 of 12454 Old 06-10-2019, 05:21 AM
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Originally Posted by artsci2 View Post
This conclusion is regarding enviornments that are noisy. In noisy enviornmenta, early reflections act like reinforcement to direct sound which improves signal to noise (voice SPL / ambient noise) ratio.

Home theaters are not noisy enviornments so this "early reflections aid in speech intelligibility" conclusion does not apply.

Ref page 8 of
https://www.jblpro.com/pub/technote/spch_intl_1.pdf
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Originally Posted by sdurani View Post
But movie soundtracks are. My comment regarding speech intelligibility was not about having a conversation in a home theatre but hearing dialogue in a movie. The soundtrack is the environment.
Early reflections of a noisy sountrack is not going to help because you get early reflections of the noise too.
The whole point of the "early reflections improve intelligibility" claim is that the signal (speech) is made louder by early reflections which makes it easier to hear above the ambient noise.

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Originally Posted by sdurani View Post
"Early reflections improve speech intelligibility"
- Floyd Toole, Loudspeakers & Rooms: http://www.wghwoodworking.com/audio/...production.pdf
From the same paragraph in your ref: "... the effects on intelligibility are negligible for the most likely lateral reflections (30–60°)..."


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Originally Posted by sdurani View Post
"There seems to be consensus in the field that some early reflections actually help make speech more intelligible."
- Mathas Johansson, Dirac white paper: http://diracdocs.com/on_room_correction.pdf
Once again, this refers to early reflections of signal. If the noise is in the sound track and it gets reflected too, there's not going to be any improved intelligibility.
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post #12441 of 12454 Old 06-10-2019, 09:11 AM
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From the same paragraph in your ref: "... the effects on intelligibility are negligible for the most likely lateral reflections (30–60°)..."
I was quoting from a bullet point in the conclusions, not the paragraph you were quoting from. From the paragraph after the one you quoted: "Looking at the overall evidence from these studies it seems clear that, in listening rooms, some individual reflections have a negligible effect on speech intelligibility, and others improve it, with the improvement increasing as the delay is reduced."

These comments are not stated as absolutes. No one said that all reflections from every direction always aid in speech intelligibility all the time. But the research does show that the improvement ranges from negligible to noticeable, rather than detrimental (as most in this hobby believe).
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Once again, this refers to early reflections of signal. If the noise is in the sound track and it gets reflected too, there's not going to be any improved intelligibility.
In a noisy environment, noise gets reflected too, not just speech. Early reflections help the brain sort it out. Note that the quotes about speech intelligibility from 'Loudspeakers & Rooms' and the Dirac room correction paper are in the context of home theatre (or at least home audio playback), not a noisy factory floor or busy classroom.

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post #12442 of 12454 Old 06-25-2019, 06:13 AM
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I'm in the process of making some ceiling sound panels. Can I place them wherever I have space between lights. I'm making a bunch of 2' x 4' panels. Some places I can place 1 and some places I can place 2. Would treating 40-60% of my ceiling make sense?
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I'm in the process of making some ceiling sound panels. Can I place them wherever I have space between lights. I'm making a bunch of 2' x 4' panels. Some places I can place 1 and some places I can place 2. Would treating 40-60% of my ceiling make sense?
You still need to make sure the panels cover the first reflection points from your seating.

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post #12444 of 12454 Old 06-25-2019, 04:37 PM
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You still need to make sure the panels cover the first reflection points from your seating.


Thanks for the reply. I have the first reflection points on the side walls already taken care of.


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post #12445 of 12454 Old 06-26-2019, 05:17 AM
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Thanks for the reply. I have the first reflection points on the side walls already taken care of.


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I was talking about first reflection points of your ceiling. Side walls are not the only first reflection points.

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post #12446 of 12454 Old 06-26-2019, 07:07 AM
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I was talking about first reflection points of your ceiling. Side walls are not the only first reflection points.
Sorry I should of clarified. My plan is to load up as much panels in front of my seating area. Behind the seating I will place them in open areas. I have 3 rows of lights, smoke detector, and 2 rows of Atmos speakers I have to work around. I also have a 30" bulkhead that runs the length of the room on the right side. I guess I could place panels all the way across it?
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post #12447 of 12454 Old 06-30-2019, 11:11 AM
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I have heard several recommendations for filling bags with insulation for use as corner bass traps, but I'm wondering what size bags to use. I have some 39 gallon bags. Will those be big enough?
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post #12448 of 12454 Old 07-01-2019, 02:45 PM
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If you can't find a single bag big enuf for the whole bundle like Roxul, -SnS ,-
use 2 of them from the ends and seal it with duct-tape. . .

just how much real bass trapping - well- it depends

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post #12449 of 12454 Old 07-01-2019, 03:14 PM
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Floor bounce , ( of bass, mid bass, mids, etc.) between speakers, LCR presumably, and MLP . . .

beyond the recommendation for a thick carpet with rug pad

- under an area carpet, 5 x 7, no rug pad- it's not wall to wall
maybe several , 4 or 5, anti-fatigue mats, in a single layer of course, held together with ducttape at the edges, what ever it takes

this: as today's deal Anti-Fatigue Kitchen Mat
$21.99 $69.99 69% off List , seems more cost effective wrt $/ft^2.

considering it's a good thickness, about 1 1/8th"

what are folks using or have used on the floor, other than thick carpet?

TY

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post #12450 of 12454 Old 07-01-2019, 03:30 PM
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^ an initial search doens't reveal composition but
may one assume this is a high density foam,?

given the unprecedented thickness

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