Diffuse vs Dampen/eliminated

M

Mr Peabody

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Joined
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Location
St. Louis, MO, USA
I recently changed some things in my listening room, removed two large wood cabinets that housed my gear and stored stuff and replaced them with a more traditional equipment rack; I got rid of a large DLP TV that was between my speakers, I did cover the screen when listening to 2-channel. I'm leaning toward a projector and the screen would be hidden when not in use.

So now I have a bit of reflection, like the sound of a room without a lot of furnishing, it's not bad but I can hear it when standing and talking or clap. I am firmly convinced our room is a very important part of our system performance. So I'm beginning to look into what to do to improve my room acoustics.

My room is heavy carpet over concrete, drywall, rectangle in shape with the system on one short wall. The rear of the room is not completely open but does have a larger than normal opening, no door. Odd measurements, about 14 x 22 or so.

I have been in treated rooms with panels to eliminate reflections but to my ears I just didn't care for the overall sound of the room, I can't explain it, though the audio sounded great it just didn't seem natural to have the room so dead. At an audio show I heard MBL using diffusers and I really think that's the way I want to go. The system sounded great but the room allowed for harmonics. I think "harmonics" is proper. The music seemed to still be alive and natural opposed to being heard and going nowhere.

So any experience or advice in treating my room would be appreciated, dampen but slightly? diffusing is the way to go? mix things up? etc.

Also, any brands of treatments? I've looked at Auralex who offers products that does both stop or diffuse.
 
Mr Peabody said:
I recently changed some things in my listening room, removed two large wood cabinets that housed my gear and stored stuff and replaced them with a more traditional equipment rack; I got rid of a large DLP TV that was between my speakers, I did cover the screen when listening to 2-channel. I'm leaning toward a projector and the screen would be hidden when not in use.

So now I have a bit of reflection, like the sound of a room without a lot of furnishing, it's not bad but I can hear it when standing and talking or clap. I am firmly convinced our room is a very important part of our system performance. So I'm beginning to look into what to do to improve my room acoustics.

My room is heavy carpet over concrete, drywall, rectangle in shape with the system on one short wall. The rear of the room is not completely open but does have a larger than normal opening, no door. Odd measurements, about 14 x 22 or so.

I have been in treated rooms with panels to eliminate reflections but to my ears I just didn't care for the overall sound of the room, I can't explain it, though the audio sounded great it just didn't seem natural to have the room so dead. At an audio show I heard MBL using diffusers and I really think that's the way I want to go. The system sounded great but the room allowed for harmonics. I think "harmonics" is proper. The music seemed to still be alive and natural opposed to being heard and going nowhere.

So any experience or advice in treating my room would be appreciated, dampen but slightly? diffusing is the way to go? mix things up? etc.

Also, any brands of treatments? I've looked at Auralex who offers products that does both stop or diffuse.
Click to expand...

Take a look at Vicoustics. http://www.vicoustic.com/ That's what I use (and carry). Very happy with the results.

http://www.vicoustic.com/product/cinema-round-premium
 
Mike, your not listed on their website yet as to "where to buy" in the U.S.
Might want to get them to update their site.
Looks like nice products
 
jadedavid said:
Mike, your not listed on their website yet as to "where to buy" in the U.S.
Might want to get them to update their site.
Looks like nice products
Click to expand...

Thanks. I will let them know. This is not uncommon (unfortunately).
 
kiwi_1282001 said:
Yes, I know what you mean, over damped rooms don't sound natural. For this reason I am a strong advocate for the use of diffusion, particularly at early reflection points. The Auralex stuff is dubious and I'd recommend you look at more credible suppliers.
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Kiwi,

We have somewhat different viewpoints on this subject.

Hope you don't mind if I interject a comment & question...

Everyone knows that the frequency response of ANY speaker - when measured well off-axis (such as the angle one might encounter at an early reflection point) - is going to be unpleasant. In fact, it is very colored, in a negative manner.

So why would you want to disperse or diffuse a badly colored sound anywhere into your room?

Best,

Jim
 
Treating your room can make a big difference to the sound , both positive and negative, knowledge of which direction to go and what type of treatment is necessary can save you alot in time and money, unless of course, the experimentation and journey is part of the plan ... :)


Many a room have been improved by yanking out unnecessary treatments ....


Regards...
 
Jim Smith said:
Kiwi,

We have somewhat different viewpoints on this subject.

Hope you don't mind if I interject a comment & question...

Everyone knows that the frequency response of ANY speaker - when measured well off-axis (such as the angle one might encounter at an early reflection point) - is going to be unpleasant. In fact, it is very colored, in a negative manner.

So why would you want to disperse or diffuse a badly colored sound anywhere into your room?

Best,

Jim
Click to expand...

Hello Jim,


Because reflected waves return at different phase angles and add to the ambient quality of the sound , distance from the wall and time of arrival is best controlled by diffusing than absorbing. Absorption can lead to that dreaded "dead " sound that some mentioned, this is not to say absorption is not necessary, there are many situations where absorption is beneficial , especially with bright speakers, speakers which over power the room and poor RT60 times ...


Regards ...
 
a.wayne said:
Hello Jim,


Because reflected waves return at different phase angles and add to the ambient quality of the sound , distance from the wall and time of arrival is best controlled by diffusing than absorbing. Absorption can lead to that dreaded "dead " sound that some mentioned, this is not to say absorption is not necessary, there are many situations where absorption is beneficial , especially with bright speakers, speakers which over power the room and poor RT60 times ...


Regards ...
Click to expand...

Thanks!

I guess we have to agree to disagree.

FWIW - My viewpoint comes from practical experience, having successfully voiced many hundreds of systems.

Of course, I do think that there is art & science to be applied that are often unknown - or worse - ignored re absorption... :sigh:
 
I thought I'd come back and share where I was at.

A sampling of Auralex was in a local music store, upon inspection I ruled it out.

I did visit vicoustics, I can't remember why nothing happened, maybe I couldn't find my way.

I spoke to a gik rep, the product he recommended would have taken to much area in my room. One of those guys who had you squirming in your chair because you realize how much you have wrong in the room you can't, or, don't want to change, LOL

I was leaning hard toward Acoustic Geometry's Curved Diffusers and maybe something for the corners. I liked the theory behind the diffusers, which are really a combo of bass trap & diffuser. A big concern was no dealer in my entire state and a 50% restock fee. I certainly planned to keep them if they work, but, what if

A friend brought over a few of the DIY Corning 703 panels that are already made up. They are about 2x4 ft. and around 4 inch thick. He sat one on each wall around the 1st reflection and two on the wall behind the speakers and facing me. Those two worked there better than in the corners. Absorption is not the way I thought I wanted to go but with just those 4 to play with the result was amazing. At first the room absent of reflection seemed to feel a bit closed in. After hearing what I'd call dramatic improvement in familiar music I think I can live with it.

You all know already, but I wish I had played with actual room treatments much earlier, better vocal intelligibility, improved bass, incredible revelation of fine details, nice. The downside, low WAF. But, she designated my listening area to the lower level for some reason, LOL

I wonder what people did for treatments before the internet, you sure can't walk in off the street to get any, or help. My friend has these extra and willing to part with them, so being able to try them first, and, the great results, it looks like the way I will be going.
 
That's great that you get to hear the results of the product before buying. Taming the first reflection point is quite often very rewarding. I tried absorption panels there and like you found a more relaxed "quieter" sound. Initially I enjoyed the change but as time went on I felt the music lacked drive or "boogie factor". A friend turned me on to the Acoustic Geometry "curves". Placing them at the first reflection point brought back that "toe tapping" feeling to the music. Furthermore, based upon their half circle construction, slight placement changes result in changing width and depth of the soundstage. Perhaps as an experiment you could take some large pieces of cardboard and slightly roll them into a half circle shape approximating the AG Curves. This would give you an idea of the results of the radial diffusion from the curves.
Good luck and have fun with it.
 
It would be great to have been able to try the curve diffusers. From what I've read about them I doubt I could imitate one. There's an internal membrane that traps bass, then at a certain point from there up is diffused. In my opinion their ridiculous restocking policy is probably a stumbling block to more business. But maybe the company had a bad experience that caused it.

I've also read, "you can't have too much bass trapping", however, I think I have to be careful with the absorption regarding mids/highs. With absorption it seems the 703 Corning is like the benchmark.

I hope I don't get restless with the effect. The sound is some more relaxed but actually eliminating the reflections allowing me to hear more into the recording gives a better sense of melody.

I will still remember Acoustic geometry and folks like that have chimed in here have been converted to diffusion for a reason. Plus, some of the companies at shows use the diffusers to help in their room. For now, it's a matter of circumstance.

jadedavid said:
That's great that you get to hear the results of the product before buying. Taming the first reflection point is quite often very rewarding. I tried absorption panels there and like you found a more relaxed "quieter" sound. Initially I enjoyed the change but as time went on I felt the music lacked drive or "boogie factor". A friend turned me on to the Acoustic Geometry "curves". Placing them at the first reflection point brought back that "toe tapping" feeling to the music. Furthermore, based upon their half circle construction, slight placement changes result in changing width and depth of the soundstage. Perhaps as an experiment you could take some large pieces of cardboard and slightly roll them into a half circle shape approximating the AG Curves. This would give you an idea of the results of the radial diffusion from the curves.
Good luck and have fun with it.
Click to expand...
 
When using the curves at the first reflection point the Bass membrane is of little to no effect as it is the 180 degree reflection pattern that will affect the sound most thus the quick DIY experiment with the cardboard. When using the Curves in the corners or by the room boundaries is where the bass traps will have a greater positive effect.FWIW.
 
Balanced between diffusion and dumping is very important, but we must not forget to room dimension as well. Square is not good, better is rectangle, wall distanc shell not be in multiplications.
 
hikerneil said:
Which direction is best for the long axis of a rectangular room?
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Martin Logan Montis Speakers
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https://www.linkwitzlab.com/rooms.htm
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Well, you can try placing on the long wall, but the short wall will allow you to sit further back, and that's what you want with M/L's (Dipoles), check your owner's manual if in doubt.

I mean my M/L Aerius speakers are 3-feet from the front wall per the owner's manual, that alone is going to shrink one dimension of the room.
 

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