[AllanS]

Any experience with and/or recommended front wall diffusion products?  In addition to floor standing or wall mounted products either side of the TV I’d like to consider something to place in front of the TV when listening.

I currently have GIK impression series corner traps/diffusers behind the M4s (and on the rear wall) but have been advised to add front wall diffusion to improve soundstage.

Also has anyone experimented with sonotubes for diffusion?

Thank you.

[dpatters]

I use the ATS diffusers with good results.


Don P

[Charles Xavier]

I use the ATS diffusers with good results.


Don P

Does the diffusers help with the TV being reflective?

[Charles Xavier]

Any experience with and/or recommended front wall diffusion products?  In addition to floor standing or wall mounted products either side of the TV I’d like to consider something to place in front of the TV when listening.

I currently have GIK impression series corner traps/diffusers behind the M4s (and on the rear wall) but have been advised to add front wall diffusion to improve soundstage.

Also has anyone experimented with sonotubes for diffusion?

Thank you.

I'm thinking these since they are light and can be moved easily.


https://www.gikacoustics.com/product/gik-acoustics-gridfusor/

[dpatters]

Does the diffusers help with the TV being reflective?

Yes. I had absorption first and felt the sound was a little dead. I much prefer diffusion. The 86” tv is flat against the wall which helps. It’s not perfect but but I’m really happy with the sound overall.

Don P

[Mr. Big]

Any experience with and/or recommended front wall diffusion products?  In addition to floor standing or wall mounted products either side of the TV I’d like to consider something to place in front of the TV when listening.

I currently have GIK impression series corner traps/diffusers behind the M4s (and on the rear wall) but have been advised to add front wall diffusion to improve soundstage.

Also has anyone experimented with sonotubes for diffusion?

Thank you.

1st reflection point on each side wall is needed, and 2 panels more on your front wall. 24 x 48 2" thick absorbers with diffraction built-in beside each window, GIK sells them, and you have the best of both worlds. and get some heavy curtains for the windows that will most certainly help imaging in the center, I use ASC 8" x 48" 3 of them behind my blinds, right, dead center, and left, you don't see them with the curtains. A few pictures from my old system with Quads and bamboo curtains and the 3 panels and one current with my Spatial M3 Shappries and curtains the panels are set on the window seal behind my blinds and I have the blinds tilted somewhat upward and they work then as diffraction. I tried them facing down and imaging and tone were negatively impacted believe it or not. I had more panels and the 1st reflection points at one time but the room looked good but like a studio with nothing but panels, so I decided to make the room look more warm and inviting so I had large canvas panels made for me. These were one of a kind like the Beatles alt. Cover for Sgt. Pepper and the Elvis and on the other side wall is another large 48x60" canvas print and another 8"x48" ASC panels so to match the wall you see in the picture is all the same on the left wall that you do not see. So both sides are identical thus perfectly balanced sound from both speakers. 3 pictures in the same room over the years, the last one was perhaps the best sonics but I wanted a more inviting look so the Cavans prints started.

My room has no back wall due to it being an open loft to the family room below. So the wall the speaker sees is 30 or more feet away.








 

[TomS]

RPG BAD Arc panels in front
https://www.rpgacoustic.com/product/bad-arc/

I also cover the TV.

[Charles Xavier]

RPG BAD Arc panels in front
https://www.rpgacoustic.com/product/bad-arc/

I also cover the TV.

Is just the 1 panel on either side of the tv enough for diffusion?

[WGH]

Any experience with and/or recommended front wall diffusion products?

Before buying more diffusion/absorption products I suggest reading the Stereophile article:

NWAA Labs: Measurement Beyond The Atomic Level
https://www.stereophile.com/content/nwaa-labs-measurement-beyond-atomic-level

Absorption is the most common treatment used in listening rooms. The measurement of absorption was first described by Wallace Sabine, who compared the reverberation times of a room with and without absorption. This difference was then converted to units of absorption using this formula:

A = 0.9210(V*d/c)
where
A = equivalent absorption area in m2,
V = volume of reverberation room in m,
c = speed of sound at ambient temperature and humidity in m/s,
and d = decay rate in dB/s.

Most of what we think we know about absorption is wrong! Absorption calculations in use today can err by as much as 85%. The biggest error concerns how important the area of absorption is in the calculation of how much absorption is needed.

"DeGrandis has done some unbelievable research in the field of diffusion," Ron said. "He's come up with a computer program that allows him to simulate what happens to a design when he changes parameters. "We've done the same research with diffusion, where shape is again key. I'm sorry, but almost 90% of what's out there, theory-wise, is BS. For example, you can't use a block's length in a 'skyline-style' diffuser to determine the frequency range that it affects."


So what does work?

PolyFlex diffusers. The only drawbacks I see is they are ugly and too cheap. An acoustically transparent box around them fixes the ugly part, then they are no more intrusive as absorbing or scatter panels that may or may not work. The articles and case studies on the AV Room Service site is a crash course on state-of-the-art acoustic science.
https://avroomservice.com/

 

The Bad Arc products look interesting and use the same principal as the PolyFlex diffusers.

[TomS]

Is just the 1 panel on either side of the tv enough for diffusion?

Of course every room is different, so who knows. Here is what I used prior. I don't think the pretty face panels do much for this other brand acoustically. They also absorb, but I removed them and put much bigger and thicker traps in the rear of the room. I originally bought the BAD Arcs to cover the TV as they're light and easy to move in and out of place, but I liked them better directly behind the speakers when I changed to the SRA Scuttle rack.

[AllanS]

Great options.  Many thanks!  With options comes the need to better understand needs.  The rabbit holes just get deeper and deeper.  At least they're interesting.

I'm thinking these since they are light and can be moved easily.
https://www.gikacoustics.com/product/gik-acoustics-gridfusor/

Perfect for sitting in front of the TV

Before buying more diffusion/absorption products I suggest reading the Stereophile article:

NWAA Labs: Measurement Beyond The Atomic Level
https://www.stereophile.com/content/nwaa-labs-measurement-beyond-atomic-level

PolyFlex diffusers. The only drawbacks I see is they are ugly and too cheap.
https://avroomservice.com/

The Bad Arc products look interesting and use the same principal as the PolyFlex diffusers.

I read but forgot about the Stereophile article and related AVS content.  Fascinating stuff and a necessary reread. 
GIK also has something similar in appearance to the BAD Arc product.
Mr Big has the fix for the ugly part.

1st reflection point on each side wall is needed, and 2 panels more on your front wall. 24 x 48 2" thick absorbers with diffraction built-in beside each window, GIK sells them, and you have the best of both worlds. and get some heavy curtains for the windows that will most certainly help imaging in the center, I use ASC 8" x 48" 3 of them behind my blinds, right, dead center, and left, you don't see them with the curtains.

Hiding the treatments behind curtains is brilliant.  The wife will appreciate it.  If effective in my space I also appreciate the narrower ASC option.
I should have used a wider view image. The space is asymmetric.  RH wall has GIK panels.  I also have similar freestanding panels but don't recall if I've ever concentrated on the sound stage with them in place either side of the rack.

[DaveWin88]

Before buying more diffusion/absorption products I suggest reading the Stereophile article:

NWAA Labs: Measurement Beyond The Atomic Level
https://www.stereophile.com/content/nwaa-labs-measurement-beyond-atomic-level

Absorption is the most common treatment used in listening rooms. The measurement of absorption was first described by Wallace Sabine, who compared the reverberation times of a room with and without absorption. This difference was then converted to units of absorption using this formula:

A = 0.9210(V*d/c)
where
A = equivalent absorption area in m2,
V = volume of reverberation room in m,
c = speed of sound at ambient temperature and humidity in m/s,
and d = decay rate in dB/s.

Most of what we think we know about absorption is wrong! Absorption calculations in use today can err by as much as 85%. The biggest error concerns how important the area of absorption is in the calculation of how much absorption is needed.

"DeGrandis has done some unbelievable research in the field of diffusion," Ron said. "He's come up with a computer program that allows him to simulate what happens to a design when he changes parameters. "We've done the same research with diffusion, where shape is again key. I'm sorry, but almost 90% of what's out there, theory-wise, is BS. For example, you can't use a block's length in a 'skyline-style' diffuser to determine the frequency range that it affects."


So what does work?

PolyFlex diffusers. The only drawbacks I see is they are ugly and too cheap. An acoustically transparent box around them fixes the ugly part, then they are no more intrusive as absorbing or scatter panels that may or may not work. The articles and case studies on the AV Room Service site is a crash course on state-of-the-art acoustic science.
https://avroomservice.com/

 

The Bad Arc products look interesting and use the same principal as the PolyFlex diffusers.

I agree that curved (constant-radius) diffusor might be the best solution, as you're not interrupting the transient's important to sound imaging. I just bought a couple of different room treatment options. ASC tubes and Acoustic Geometry panels for the first reflection. Of course I didn't bother to match any of the colors I haven't fired the system up yet. So yeah diffusion behind the speakers might be the best solution.


A great video on the subject.
https://www.youtube.com/watch?v=aI098eNsmuY



 

[Bob2]

[DaveWin88]

Thank you. I only have the curved panel next to the GIK for comparison. I'm on this kick of not running my air this year for whatever reason that I haven't been listening in a couple weeks. Been 80ish in the house

Well I decided to turn my air on at least so I can try these panels out this evening.

[AllanS]

I agree that curved (constant-radius) diffusor might be the best solution, as you're not interrupting the transient's important to sound imaging. I just bought a couple of different room treatment options. ASC tubes and Acoustic Geometry panels for the first reflection.

I’ll be interested to hear your impressions.  Thanks for the link. 
I know there’s a lot of good science behind all this but it sure does feel like treatments is as much of a crap shoot as anything else in this hobby.
Of course I figured out today that the soundstage problem I thought was room asymmetry is more likely a hearing problem.  So I’m not sure treatments will resolve my issue - at least not room treatments.

[DaveWin88]

OK guys / AllanS. I'm going to start with the crazy talk first, then explain what I'm hearing.  As far as the Acoustic Geometry curved diffusors go,  there's no option. You have to have these for your first reflections. When I first started to listen to music tonight, I was immediately shocked at how different it sounded. It's probably the real first time hearing the Spatials on their own if you will. The tone was noticeably better? consistent for absolute. I was playing vinyl for the first hour or two, then switched to Cd's. Side note, the Jc5 and even the A21+ sounds quite a bit better after listening for two - three hours. One of the biggest things is that the panels completely disappear, and they take some of the wall with it. I know that sounds weird but what you normally hear from the extreme sides of your head just flat out mostly gone. John Calder from the manufacturers video was not lying about imaging. For the first time I've had the A21-JC my image is tighter, more focused, and very very well grounded. Before it was always vague and floaty if you will.   I'm hearing detail like I've never heard mostly because you're not getting the delayed sound and more importantly the tonal differences that come along. These will give you an honest look of what your system actually sounds like. Guys this is not subtle. It's almost like the first time hearing your Spatials and being floored at how much less they interact with the room. These ADD to the same effect. Full disclosure. I do have my speakers closer together 6 foot apart to be exact. But I've had these for a year and a half and I know very well what they sound like in this room. So the soundstage did get narrower (focused) but if you close your eye's it seems very appropriate. You definitely get a better sense of the venue, and venue boundaries. Tomorrow after work, I'm spreading my speakers further to widen the soundstage a tad. A video from The Absolute Sound that they did a couple weeks ago,  Robert Harley stated that if there was only one thing you did to your room this should be it. Man he was so spot on, and maybe even understated. What it did for the image, detail (by getting your room out of the way, and the tone of the presentation) the panel completely I mean completely disappear. It's staggering. You know we buy new cables and such to try and improve the soundstage and detail,  and it never seems to get you there. This is like buying a component for you rig that actually achieves it. I'm so impressed that I'm contacting the company and complimenting them on such a wonderful product. This is major. I do still have bass issues, but I'm determined to get it figured out. btw the fabric I chose looks like it's right out of the 60's us old guys can appreciate that. This also fixed the fact that my room is less than ideals like most of us. What a great product.





Guys this is a very big improvement.
   

[AllanS]

I'm going to start with the crazy talk…

If disappearing walls and vague floaty image is crazy talk then we’re speaking the same language.
 I asked my (incredibly patient) wife to sit and sample a few sound stage placement test tracks yesterday and point to where she was hearing stuff come from. (Native DSD “Audiophile Speaker Set-Up” tracks 58-76)
https://www.nativedsd.com/product/2xhdft1095-audiophile-speaker-setup/.  Reaching in vague directions  she was unable to pin point where voices and test sounds were coming from (ringing bell and clapper).  For the most part vague and floaty describe very well what we both heard in these test tracks and I’ve heard in others.
 My biggest problem was pretty much everything that was supposed to emanate from the right side of the stage barely budged off center.  But even everything that was clearly left of center was not well or consistently located.  The voice, bell, and clapper, though physically located in the same place, emanated from different but indistinct locations within the sound stage.  But even these were inconsistent.  The voice location was vaguest.  The bell and clapper locations were more distinct but very different.  I wouldn’t describe any of this as floaty but I have plenty of other examples where the image literally floats left to right as though the performer is wandering. 
 I’m sure the reasons for all this is a mess of physics, psychoacoustics, and hearing loss but it’s all quite distracting and often times has me wondering if cans is the “better” option. (Steve Guttenberg “What happens when AUDIOPHILES take the ROOM out of the equation?” https://www.youtube.com/watch?v=4eCbJfLSYGg&t=24s

[AllanS]

As far as the Acoustic Geometry curved diffusors go,  there's no option.
 Guys this is a very big improvement.

Thank you. I’ve got more homework to do but these will get a serious look.

[mrotino332]

In my narrow room I've experimented quite a bit and I've decided on small low bass traps in the front corners and lower front wall with a combination diffusion/absorption in the upper corners and all diffusion on the front wall.
My system is in the basement so looks does not matter so much for me.

I found adding panels at the first reflection point did not change the sound so removed them.  Probably because my speakers are only about one and a half feet from the side walls and since these are open baffle they do not radiate much sound to the side.  Also the AMT tweeters have a waveguide which limits extreme lateral dispersion.

I do have combination absorption/diffusion panels at the second reflection points.

[Mr. Big]

OK guys / AllanS. I'm going to start with the crazy talk first, then explain what I'm hearing.  As far as the Acoustic Geometry curved diffusors go,  there's no option. You have to have these for your first reflections. When I first started to listen to music tonight, I was immediately shocked at how different it sounded. It's probably the real first time hearing the Spatials on their own if you will. The tone was noticeably better? consistent for absolute. I was playing vinyl for the first hour or two, then switched to Cd's. Side note, the Jc5 and even the A21+ sounds quite a bit better after listening for two - three hours. One of the biggest things is that the panels completely disappear, and they take some of the wall with it. I know that sounds weird but what you normally hear from the extreme sides of your head just flat out mostly gone. John Calder from the manufacturers video was not lying about imaging. For the first time I've had the A21-JC my image is tighter, more focused, and very very well grounded. Before it was always vague and floaty if you will.   I'm hearing detail like I've never heard mostly because you're not getting the delayed sound and more importantly the tonal differences that come along. These will give you an honest look of what your system actually sounds like. Guys this is not subtle. It's almost like the first time hearing your Spatials and being floored at how much less they interact with the room. These ADD to the same effect. Full disclosure. I do have my speakers closer together 6 foot apart to be exact. But I've had these for a year and a half and I know very well what they sound like in this room. So the soundstage did get narrower (focused) but if you close your eye's it seems very appropriate. You definitely get a better sense of the venue, and venue boundaries. Tomorrow after work, I'm spreading my speakers further to widen the soundstage a tad. A video from The Absolute Sound that they did a couple weeks ago,  Robert Harley stated that if there was only one thing you did to your room this should be it. Man he was so spot on, and maybe even understated. What it did for the image, detail (by getting your room out of the way, and the tone of the presentation) the panel completely I mean completely disappear. It's staggering. You know we buy new cables and such to try and improve the soundstage and detail,  and it never seems to get you there. This is like buying a component for you rig that actually achieves it. I'm so impressed that I'm contacting the company and complimenting them on such a wonderful product. This is major. I do still have bass issues, but I'm determined to get it figured out. btw the fabric I chose looks like it's right out of the 60's us old guys can appreciate that. This also fixed the fact that my room is less than ideals like most of us. What a great product.





Guys this is a very big improvement.
   

Where did you buy them?