Art Diffusor?

[Bad Radio]

Hi,

I'm looking for a skyline type diffusor made from wood, without going the DIY route. Tried doing a search, but nothing came up regarding the Art Diffusor Model W. Anyone familiar with these?

Art Diffusors®

[SaSi_SiDi]

The idea behind the skyline diffusor is to have "random" pattern so that the soundwaves get a random diffusion pattern. These are too stylized to be real diffusers.

I would take the specs with a bit of caution as well. The first model claims a working range from 125Hz. In order for a diffuser to go that low the depth needs to be more than 20~30" and the model is only 9.5" deep.

[Ethan Winer]

^^^ Agreed.

[Bad Radio]

Thanks for the input, guys.

In your opinion, what makes these a better alternative?

RPG Diffusor Systems

RPG Diffusor Systems

RPG Diffusor Systems

[SaSi_SiDi]

IMHO, these are actually diffusors, designed to be so from the functional angle rather than the looks.

The first one is a two dimensional version that disperses sound waves both vertically and horizontaly (assuming it is mounted on a wall).

The second one is a 1D version that only disperses horizontally.

The third one is a more complex and ambitious design being two 1D diffusers in one. The first pattern is for lower frequencies and the smaller repeated pattern inside each large cavity is "tuned" to the higher frequencies.

The 1D diffusor is good when you don't want to send waves to the ceiling or floor - for example. One example might be locating this on a rear wall with the side walls treated for reflections. That scenario would diffuse the sound field and redirect part of the rear reflections to the sidewalls for absorbtion or further diffusion. That, of course, is assuming the "grooves" have a vertical orientation.

The 2D version is used - according to my reading - in larger spaces. I've seen such panels placed on walls where the panel takes up only a fraction of the height. There is no reason why it could also be used on a ceiling.

The difractal is an interesting idea that could actually work. I am a bit sceptical about the effectiveness of the high frequency tuned QRDs that are located deep in the wells of the low frequency tuned main QRD. But it could be that high frequencies easily penetrate the low frequency wells.

QRDs and skylines are by definition large and bulky. It is an issue for transportation unless they are sold close to where you live. Otherwise, it is a tedious but easy project to make yourself with minimal woodworking skills.

And a last remark. It has been found that poorly constructed QRDs exhibit absorbtion as well as diffusion. The small open seams (from poor construction) function as helmholz resonators. It is up to an educated constructor to combine both with a bit of knowledge. For example, a small slit on the back cover or shallow wells combined with some rockwool in the back of the construction could double the QRD into a tuned absorber - of unknown effectiveness. But don't take my words literally - this is wide open for experimentation and debate.

[Nordenstam]

+1!

Check the polar plots at: http://www.acousticsfirst.com/artdif...F_Art_E_PP.pdf

The low end is "always" diffuse (due to size) - while the reflection gets more and more specular as the frequencies gets higher. Specular being a reflection going out with the same angle as it originated. The angle is zero in the case of the plots linked above so we should expect the diffusor to not have energy concentrated in the middle of the plot. Ideal curves for these pictures, for a diffusor claimed to work from 125 to 16000 Hz, would be the 125Hz curve, at all frequencies. As you can see, that's clearly not the case.

Here's some other plots for comparison:
http://www.rpginc.com/download/Broch...ping%20Web.pdf
http://www.auralex.com/testdata/PolarPlotTFusor.gif


PS: Sasi-sidi: I think the 2D can be better for smaller spaces than the 1D. From what I've understood, the 1D's needs a bit more distance for the scattered waves to mix properly.

[Bad Radio]

Wow, awesome replies... thanks so much! I'm looking for something for my back wall and trying to find a diffusor that actually works and isn't made of polystyrene (and doesn't look like a set of window blinds). The control room will be 22-25' long (still planning) and the mix position will be more or less 38% from the front wall. What do you guys think of these:

GIK Acoustics: GIK Elite Poly

They're fairly new, but as I understand, Glenn makes excellent products. I didn't see any specs listed on the site though.

[bumbum]

Originally Posted by Bad Radio

I'm looking for something for my back wall and trying to find a diffusor that actually works and isn't made of polystyrene

why no polystyrene, what's wrong with it ?

[Bad Radio]

Originally Posted by bumbum

why no polystyrene, what's wrong with it ?

I've used it in the past and found it's not particularly durable. That and I think it's way overpriced for what it is.

[Glenn Kuras]

Originally Posted by Bad Radio

Wow, awesome replies... thanks so much! I'm looking for something for my back wall and trying to find a diffusor that actually works and isn't made of polystyrene (and doesn't look like a set of window blinds). The control room will be 22-25' long (still planning) and the mix position will be more or less 38% from the front wall. What do you guys think of these:

GIK Acoustics: GIK Elite Poly

They're fairly new, but as I understand, Glenn makes excellent products. I didn't see any specs listed on the site though.

Hey man if you would like to shoot me a email or call us we can go over your room to see if the poly is right for your room.

Glenn

[Bad Radio]

Thanks, Glenn! Will contact you next week... still finalizing the room layout and dimensions.