psychoacoustics, direction of diffused reflections

[hsal]

There is alot of threads about rfz rooms and discussion about the time gap between direct sound and the diffuse reflections and the soundlevel of these diffuse reflections.

Have there been any studies or theories about how a listener percieves scattered sound from different angles?

Is there an added benefit of having diffusers on the backwall beyond the large distance and timegap?

[johndykstra]

Back when SAC was a frequent poster here, he would always make reference to the diffuse return being "laterally arriving". Having done some research on the subject, I've found "laterally arriving" to mean from an angle of 120 degrees and less. The topology of the room will dictate how far lateral you can go, before the side walls are simply too close which would mean a shortened ISD gap.

Most RFZ control rooms feature a large centered diffuser on the back wall. This orientation would be 180 degrees of course. However, if the diffuser is wide enough, it can very well stretch into the 120 degree mark.

In my pending design, I don't have the room width to make 120 degrees doable. I think I'm around 160 degrees or so. As a fix, I have incorporated some vertically spreading 1d diffusers along the bottom of my side walls. The idea being that sound on the way back will not diffuse back to the listening position, rather continue back but spread up and down. The main function of my side wall diffusers is upon the return... sound that would hit the wall too low to be of any use is instead diffused upward. This should not only provide a bit more lateral arrival, but hopefully add to the density of the return as well.



Time will tell if the higher, horizontally spreading 1d's on the side wall will "splash" the ISD. These side wall units are modular frames that will fit between the stud cavities of the side walls. This allows me some amount of trial and error as the room takes shape.

There's a lot more discussion on this and other aspects of my efforts in the control room thread in my signature line. Work is barely underway here, so no way of knowing if my understanding of the concept and principles are correct yet. However, the reassurances of Andre and other heavy hitters has me at least feeling halfway confident it will be a success.

[hsal]

I have some qrd diffusors , and from my experience I prefer the reflections coming from behind listening position, but this might have to do with the room geometry , distance to the borders and asymetry in the transverse plane of the room.

I might move things around abit so that I can try out a placement on the back of the sidewalls.

[jonessy]

Have there been any studies or theories about how a listener percieves scattered sound from different angles?

Read anything written by Mike Barron, as early as the 70's.

[Torea]

Originally Posted by johndykstra

Back when SAC was a frequent poster here...

Seriously. SAC, where ya been?


I think he stopped responding after that argument in that wrong-forum thread. Too bad =(

[hsal]

Read anything written by Mike Barron, as early as the 70's

I`ll look into it, thanks

Seriously. SAC, where ya been?

+1

[Jens Eklund]

Originally Posted by Torea

Seriously. SAC, where ya been?


I think he stopped responding after that argument in that wrong-forum thread. Too bad =(

SAC decided to leave this forum due to;

"XxxXxx´s ignorance, constant argumentative responses, and personal attacks."

If anyone wants to get in contact with him, send me a PM.

[Jens Eklund]

If anyone is interested in learning more about the original topic, I suggest reading studies by Leo Beranek, Manfred Schroeder, Don Davis or Peter D'Antonio.

[PaulP]

Originally Posted by Jens Eklund

SAC decided to leave this forum due to;

"XxxXxx´s ignorance, constant argumentative responses, and personal attacks."

While his character was exemplary...

[hsal]

I suggest reading studies by Leo Beranek, Manfred Schroeder, Don Davis or Peter D'Antonio

Thanks

I have "acoustic absorbers and Diffusors" by D`Antonio/Cox, there is not much info on this subject from what I remember

Is there any specific text by D`antonio that covers the topic of psychoacoustics and direction of diffuse reflections?