What is the Sound of Front Wall Diffusion?

Brucemck2

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May 10, 2010
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Gunnar, I have had three areas not dissimilar from the window bay behind your right speaker and they decorative insert closer to your left speaker. For two I had a trim carpenter create a two piece unit that I could “insert” or “stand up” inside the opening to create a temporary (only visible when in use) surface that I stored in a nearby closet when not in use. (You might be able to store them on the floor behind your couch?). In both cases I experimented with surfaces until I got it right. One ended up being 2” thick fabric wrapped RPG BAD panels mounted to the wood. Another ended up being 2” fabric wrapped RPG fiberglass panel with RPG Skyline diffusors mounted in front of that. You can get the fiberglass panels made to custom sizes. The Skylines are easy to cut to size and paint. Both worked pretty well. Finally, I also used two 4” thick RPG fabric wrapped panels that my trim carpenter added “feet” to that I could prop up in an opening. Those effectively ”killed” the hollow area even without sealing - four inches thick caught most of the wave and the bounce back from the rear of the cavity hit the rear of those 4” panels. Something like that is likely to work well in both of your (potential) problem areas.
 

Gunnar

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Mar 24, 2021
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Hi sel53

I have a dedicated 2 channel only listening room tha measures 17’ front to rear wall by 12’ wide with an 8’ ceiling with wall to wall carpeting. I’ve been trying various acoustic treatment options for about 5 years. All of my comments apply only to what I hear in my room.

To answer your original question, when I installed QRD bamboo diffusers on the wall behind the speakers, it cleaned up the midrange and the high frequencies. Instruments were no longer jumbled together. Much less confusion. Voices were more articulate and I now found it easier to understand the words. The midrange & high frequencies were more open and I noticed the highs seemed to be better extended.

In my experience, there seems to be areas that are more important than others and this is where I would start.

1. Bass traps in the corners behind the speakers.

Before I added those, my room had no bass. I would spend stupid amounts money on speakers and couldn’t figure out why I had no bass. It took a couple of years to realize that the room had really bad nodes that would just eat up the bass. The bass traps helped a lot. I have them from floor to ceiling, bass problem solved!

2. The diffusers on the wall behind the speakers, in the middle.

These made a significant difference. Everything was cleaner, with noticeably better clarity. Soundstage was wider and deeper. Smaller background details that I didn’t even know were in the recoding were now revealed. Complex orchestral passages were much less confused.

3. Absorbent panels 1’ - 2’ on the side walls (if there are walls to the side of the speakers) in front of the speakers.

The purpose of these panels is to kill that first reflection bouncing off the walls in front of each speaker. This improves image specificity. Instruments within the soundstage are more stable. Again, everything is less confused.

I would also recommend playing with the placement of your listening chair by moving it closer to or farther away from the speakers. This can make a surprising difference.

The most important advise I could give you is don’t overdamp the room. This is easy to do. This will render the room dead, dull & lifeless. The only way to avoid that is to add small amounts of each option and then listen. Take your time and listen before adding more. If you’re convinced you’re going in the right direction, then add a little bit more. Again, listen carefully. If it starts to sound worse, you know you’ve added too much. Go back and take out that last bit. A properly treated room will have great energy and the music will come to life. Trust your ears, when it’s right, you’ll know it.

IMHO, the two most important things for great sound is the room and the setup. You can spend a lot of money on great components and put them in a bad room and if they are not setup properly, they will never sound good. You can buy more modestly priced gear and put it in a properly treated room and set up the gear correctly and it will sound great.

I hope these suggestions help you. Take care.

Best regards
Scot
I think you are spot on. Room and setup are keys. I have not done point number 2 yet. Will do it with something I easily can take away. Just need to figure out next step so I minimise the risk of spending for nothing and getting a thought trough result as good as possible..
 

StreamFidelity

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Jun 30, 2020
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The room is open on the right side. Total size >70 m2 with the living room corner 4,6 meter wide and 6,7 meter long. Ceiling, to the beams 3 meter. Listenposition 4,2 meter from the loudspeakers.
I understand that removing the sofa in front of the speakers is not an option. What I find worse is the glass table, which reflects a lot of sound. A tablecloth could help.

A listening distance of over 4m is questionable with this type of loudspeaker. Horns would be a solution. Or you sit closer.

These are actually the basic things that I see in your system. In my opinion, it makes no sense to think about diffusers beforehand. I hope that doesn't come off too hard about. Because I think your system is very beautiful.

I also had the situation once that something was always in the way. I've consistently gotten that out of the way while enjoying music. It takes a little effort, but what do we not do all for our hobby? :D
 

Gunnar

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Mar 24, 2021
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I understand that removing the sofa in front of the speakers is not an option. What I find worse is the glass table, which reflects a lot of sound. A tablecloth could help.

A listening distance of over 4m is questionable with this type of loudspeaker. Horns would be a solution. Or you sit closer.

These are actually the basic things that I see in your system. In my opinion, it makes no sense to think about diffusers beforehand. I hope that doesn't come off too hard about. Because I think your system is very beautiful.

I also had the situation once that something was always in the way. I've consistently gotten that out of the way while enjoying music. It takes a little effort, but what do we not do all for our hobby? :D

True, we do a lot of things, sometimes less thought through for our hobby. Normally when I am listening I put a couple of pillows on the glass table. Not just for the reflections but also for the comfort of my feet .. ...

My wife will, a week from now, visit her parents (for a week) and then I will take away the sofa and move closer to the loudspeakers. Right now horns is not a solution.
 
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