Diffusers or Deflectors around surrounds?

[DanDan]

I would love to see a measurement confirming the elimination of the bass standing wave.
I am not convinced about stereo imaging being improved by adding HF reflections, albeit diffuse, from above.
DD

 

[FargateOne]

My listening position is unfortunately on the back wall. I read that diffusors panels are good to have on the back wall when it is way back of the mlp. Do yo think that it might help even in my case? Or would it better to put more absorbtion?

 

[Bpape]

Unfortunately diffusion won't help there. You're simply too close to allow the waves to spread out of the diffuser. In that position, use thick absorbers with a limp membrane on them so they are bass/low mid absorbing only to help with the buildup by the rear wall boundary.

 

[FargateOne]

Unfortunately diffusion won't help there. You're simply too close to allow the waves to spread out of the diffuser. In that position, use thick absorbers with a limp membrane on them so they are bass/low mid absorbing only to help with the buildup by the rear wall boundary.

It is what I thought. Since the pictures was taken, I replaced the windows you see behind the mlp by rockwoll AFB and a silk tissu on it (more or less 6 pounds density) and I am searching since then how to improve it. What should I use to make a limp membrane on it?

 

[Bpape]

While the density is good, the thickness isn't most likely. Think mass loaded vinyl. Or you can use heavy duty pond liner or flat roof membrane. MLV is great to work with but generally you have to buy a whole roll which isn't cheap to buy or to ship.

How thick are the absorbers? I would be looking for 6" or more.

 

[Tonto]

Any of you guys have diffusion on ceiling in the region of 1st reflection point?

Been a while since I looked into treatments, seems like I remember panel traps were generally popular for that back then. Then diffusion started carving out its niche.

 

[FargateOne]

While the density is good, the thickness isn't most likely. Think mass loaded vinyl. Or you can use heavy duty pond liner or flat roof membrane. MLV is great to work with but generally you have to buy a whole roll which isn't cheap to buy or to ship.

How thick are the absorbers? I would be looking for 6" or more.

The back wall separates the theater room from the "basement shop" in the house. So, I took advantage of it (maybe wrongfully but you tell) and behind the fabrics, Rockwoll is 12 inches thick and I have 10 feet after that (instead of the usual 4 inches for a panel). Each "window back absorber panel" (to name it) are 24 inches X 28. You are right about quantity for mlv. I will take a look at my hardware store. Do you think that 1/2 inches thick is good?

 

[Bpape]

For the MLV, even like 1/4" is great. I would put a back on the rear absorbers maybe 3-4" behind the rockwool. With the space you have you're introducing an entire other set of room resonances to the equation from the back space.