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Treatments for Front Walls.

alitomr1979

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Hello all,

After installing about 16 square feet of acoustic panels in first reflection points of the side walls and in the rear wall, I am now really interested in something Inwas supposed to do long ago: treating mu dedicated listening room / home Theater.

It is a tiny 11’ by 10’ room, with 8’ 6” height ceiling, all concrete walls, and tile floors. Hyper reflective.

I have been reading about sound treatments and ordered a few foam bass traps because the big ones are not possible now because of space constraints, and some due cable management. What I did get was more of the Rhino Acoustic panels because I now realized the reflections were killing the sound. Something really interesting is that i didn’t even notice how much treble energy was in the room. I just could not identify the problem and it became evident as I kept installing these 1 squared feet panels.

Now I want a few for my office, and order a few of those hexagonal ones for my bedroom.

But the question I have now is for my dedicated listening room, and I have it because I haven’t found nothing particularly conclusive about it: should I treat the front walls, behind the speakers, with absorption or diffusion or should I just leave them as they are?

Leaving them as they are is almost out of the question because after being marveled by the LS50 Meta I am very interested in listening to rooms and speakers with good absorption behind. If most of the improvement from the metas come from the meta material, even with that amazing, practically inert cabinet in the LS50, I just assume there should be great benefits to get by suppressing sound that’s sent back front the speaker, to the front wall.

I am thinking about getting the best stereo listening possible in my setup.

I have a pair of R3 with dual stereo SB2000. MLP is almost a equilateral 8-9 feet triangle. I treated the rear wall because Inkept hearing lots of reflwctions from there, as I sit at roughly 1 feet about from it, and I used 4 panels in the first reflections in each side wall.

What is your take on front wall treatments?
 

Webninja

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Are you using REW to compare before and after? I think with measured frequency responses you can adjust and add/edit your treatments until you are satisfied.

Right now I have no treatments, but when I measured with a closet door open or closed, there was a visible difference in the bass frequencies (under 150Hz). I’m still adjusting and will add treatments in the future.
 
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alitomr1979

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I have a few REW measurements from before. Problem is a lost my calibration file, and that is a problem, but perhaps not a big one…

Still, even without the calibration files RT30 and RT60 numbers should be very reliable. I will try to run a few REw measurements tonight when I get a few measurements.

From the before takes I only remember I had a peak at 57hz, which is consistent with the common room mode for a room of these dimensions.
 

alex-z

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I have been reading about sound treatments and ordered a few foam bass traps because the big ones are not possible now because of space constraints, and some due cable management. What I did get was more of the Rhino Acoustic panels because I now realized the reflections were killing the sound. Something really interesting is that i didn’t even notice how much treble energy was in the room. I just could not identify the problem and it became evident as I kept installing these 1 squared feet panels.

Now I want a few for my office, and order a few of those hexagonal ones for my bedroom.

But the question I have now is for my dedicated listening room, and I have it because I haven’t found nothing particularly conclusive about it: should I treat the front walls, behind the speakers, with absorption or diffusion or should I just leave them as they are?

Leaving them as they are is almost out of the question because after being marveled by the LS50 Meta I am very interested in listening to rooms and speakers with good absorption behind. If most of the improvement from the metas come from the meta material, even with that amazing, practically inert cabinet in the LS50, I just assume there should be great benefits to get by suppressing sound that’s sent back front the speaker, to the front wall.

I am thinking about getting the best stereo listening possible in my setup.

I have a pair of R3 with dual stereo SB2000. MLP is almost a equilateral 8-9 feet triangle. I treated the rear wall because Inkept hearing lots of reflwctions from there, as I sit at roughly 1 feet about from it, and I used 4 panels in the first reflections in each side wall.

What is your take on front wall treatments?

Foam bass traps are not real bass traps. Generally speaking, foam based products are extremely overpriced, because they lack the density and thickness required for low frequency affect.

If you want to do acoustic treatment properly, use materials like fibreglass or mineral wool.

Front wall treatment is primarily used to treat speaker boundary interference response. Figure out the frequency of your SBIR, that will tell you what thickness of treatment is required.


A rug and ceiling treatment should also be added.
 
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alitomr1979

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Foam bass traps are not real bass traps. Generally speaking, foam based products are extremely overpriced, because they lack the density and thickness required for low frequency affect.

If you want to do acoustic treatment properly, use materials like fibreglass or mineral wool.

Front wall treatment is primarily used to treat speaker boundary interference effect. Figure out the frequency of your SBIR, that will tell you what thickness of treatment is required.


A rug and ceiling treatment should also be added.

Hey, thank you for taking time to reply.

This is the calculations made in the link you posted:
BA4B199C-D000-43DE-87D3-832CB0F23BBC.jpeg


I don’t know exactly what to do with this, other than moving farther to the sides, or closer to the center and a little backwards towards the front wall to eliminate the compounding effect of having the speakers with such similar distances to the side and front walls.

What else??
 

alex-z

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If you move the speakers closer to the walls, the SBIR frequency goes up, and is easier to manage with acoustic treatment.

3.5" absorption panels work best above 200Hz, and that is a standard thickness for insulation. 5.5" is also available, and that is what I recommend using if possible, it will have a lot better mid-bass absorption.
 

csepulv

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Are you using REW to compare before and after? I think with measured frequency responses you can adjust and add/edit your treatments until you are satisfied.

Right now I have no treatments, but when I measured with a closet door open or closed, there was a visible difference in the bass frequencies (under 150Hz). I’m still adjusting and will add treatments in the future.
I've also noticed the measurement and visual graph difference with a closet open and closed. But in my case, I couldn't hear any difference. (They looked different with var or 24 octave smoothing, but they looked similar with psyacoustic smoothing)
 

Webninja

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I've also noticed the measurement and visual graph difference with a closet open and closed. But in my case, I couldn't hear any difference. (They looked different with var or 24 octave smoothing, but they looked similar with psyacoustic smoothing)
Same experience here, I couldn’t hear a difference, but it was interesting to see how the frequency response changed. I would like to see how room treatments would show up in my measurements.
 

DjBonoBobo

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Maybe this helps?

 
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alitomr1979

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Maybe this helps?


It shows the possibilities with very heavy treatments. I would like to be able to hear how those graphs translate into how things sound in room. Thank you for sharing it!

I ordered several acoustic panels, and some foam advertised as bass traps in Amazon. They are not very expensive and I’ve seen a few videos where YouTubers say they work even with some nulls in 83hz.

I am also strongly considering custom
Made rockwool panels, which would be great as bass traps in corners. I can make them work… we’ll see first how the smaller foam ones work.
 

DjBonoBobo

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I would like to be able to hear how those graphs translate into how things sound in room.
I find it hard to describe. More dry, precise and "correct", but also more delicate or fragile. For example, in my experience, the more flat it gets, the more some smaller deviations become audible. So, when you start, you may not be finished for a long time, because after you dealt with the biggest problems, you may recognize new imperfections you did not really hear before.
 
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alitomr1979

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I find it hard to describe. More dry, precise and "correct", but also more delicate or fragile. For example, in my experience, the more flat it gets, the more some smaller deviations become audible. So, when you start, you may not be finished for a long time, because after you dealt with the biggest problems, you may recognize new imperfections you did not really hear before.
That you describe I think it´s something explained by what we know about psychoacoustics. I mean the "the more flat it gets, the more some smaller deviations become audible" part, and I think it is why most audiophiles tend to like more a flat frequency response, because basically what we achieve is an increased perception of detail in the music, which is a big (most) part of what we are after.

I installed 20 sq.ft. in my small room, as I said, basically treating early reflections and some reflections I kept hearing from the rear wall, and now everything is closer to what you describe. What I find amazing is that there is so much more detail in the highs, but there is also way more detail in the bass, even though I installed tiny 0.4inch width panels from Rhino Acoustics, which I suppose dont do much for low frequencies. I still hear some echoes and a rug, and about 72sq.ft. of panels are coming next week. Some of those will be used to treat early reflexions in the bedroom, but my main focus is the main room. My concern is overdoing it especially considering those panels probably are not doing much for the low frequencies.

Last night I could not take measures. I will try tonight.

Thanks for sharing this info.
 

Hipper

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On the specific subject of the front wall, between the speakers, I found that I could hear reflections off my gear when it was placed there so I moved the equipment to one side, put panel bass traps on the front wall (as I have on the rear wall) and thinner panels on feet on the outside of each speaker so that direct side wall reflections from the speakers were prevented. I never had any problems from ceiling reflections.

This link, post 60, explains my strategy for my dedicated listening room which isn't much bigger then yours:

https://www.audiosciencereview.com/...in-room-measurements.13540/page-3#post-411614

It's not attractive to look at but it sounds good to me!
 
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