Is This a Good Diffuser Design? (Picture Attached)

[SRS]

Was looking to build some more diffusers for my studio and was looking at making some similar to this design. The material would be cheap and the labor not too time consuming. But of course, I want them to be as effective as possible. The main room is already treated with bass trapping (OC 703, 4 and 6 inches thick with 703 chunking behind) and various 703 panels throughout. I am going to double up some of the 2 inch 703 panels (that are currently mounted) for lower freq absorption and want to place some diffusion at various places throughout the room.

I know that these are not mathematically designed diffusers, but wanted some advice on their possible value. Ethan? or Glenn? Or anyone???

[audiovisceral]

very cool! but why not just build a qrd? cheap, easy, and work well. mdf is cheapest. go 2'x4'x9" with 7 wells.

eg.




or if u don't mind ugly, do a skyline.

[Glenn Kuras]

I know that these are not mathematically designed diffusers, but wanted some advice on their possible value. Ethan? or Glenn? Or anyone???

I think you just answered your own question.

I would stick with a QRD or skyline type. There are plans all over gearslutz for them.

Glenn

[Ethan Winer]

Originally Posted by SRS

I know that these are not mathematically designed diffusers, but wanted some advice on their possible value.

Without testing, or knowing the size, or even hearing them, it's impossible to say. I imagine they'll be better than a bare reflecting wall.

You could do a home-made test similar to my test on the RealTraps Videos page:

RealTraps - Videos

See the last video in the list. This will at least give you some idea of their effectiveness.

--Ethan

[jayfrigo]

I'm thinking that lower wavelengths won't be affected much based on the size that I think the peaks are, but the interesting part for high and mid frequencies is that because the backs are open, there will be some interesting interactions. Some of the reflected sound from each peak will go back into the room immediately, and some will be reflected behind one of the adjacent peaks before returning.

The distribution may not be as even or spread as wide spatially or temporally as some designs, nor will the frequency range likely be as great as some, but it indeed should provide some positive results within a certain range. Without more info and some testing we can't say for sure how effective it will be, but it does look interesting. There are a couple things that concern me regarding the consistent size and flat, identical angular nature of each element, but without testing and listening I couldn't say for sure whether this will present conspicuous problems in practical applications or not. I'd actually like to see how they measure.

[SRS]

Thanks for responding everyone. I think they look intriguing, but the sound of diffusion is what I'm after. They certainly would look sweet on a back wall, especially with a group of them put together. But performance is important too, even more so definitely.

I am sure they would be better than a bare wall, but as good as a QRD or skyline? Doubtful I suppose... Ethan, wht do you think of the open back portions of the pieces of wood? Would that possibly give off a "hollow" sound at a certain frequency do you think?

I wish there were some tests on these. There are several types around too. See the pics.

[jayfrigo]

Originally Posted by SRS

Ethan, wht do you think of the open back portions of the pieces of wood? Would that possibly give off a "hollow" sound at a certain frequency do you think?

It shouldn't, especially considering the small size and both ends open.

[mltamisin]

Who makes these. I've not seen them around.

[SRS]

This seems to be the originating company, but there are several that have copied the designs. I would just make them myself.

Celestial Acoustics

[bpape]

Originally Posted by SRS

Thanks for responding everyone. I think they look intriguing, but the sound of diffusion is what I'm after. They certainly would look sweet on a back wall, especially with a group of them put together. But performance is important too, even more so definitely.

I am sure they would be better than a bare wall, but as good as a QRD or skyline? Doubtful I suppose... Ethan, wht do you think of the open back portions of the pieces of wood? Would that possibly give off a "hollow" sound at a certain frequency do you think?

I wish there were some tests on these. There are several types around too. See the pics.

If you want the sound of diffusion, use diffusors based on properly calculated, proven designs. To me, those look more like a replica of anechoic wedges which are actually normally absorbant.

Bryan

[SRS]

They are referred to as "Scatterers" and not actually diffusers. I guess scatterer is a non-technical term for non-mathematical diffuser... And from what I am gathering, less effective than mathematically designed diffusers.

[2 trak]

The diffuser design I think can use an array of small helm holtz resonators. These can be on a 1-2 inch flat sheet with the holes arranged in a grid. Then Then maybe a spaced sheet just behind that sheet. Maybe on a small angle. This is just one I have seen. You can calculate the frequencies at which the holes take the energy out by using the helm holtz equation. I will do some looking as I need to set up some for my studio and keep you guys posted on progress..


Peace


Tristan

[wonderlover]

what is QRD?

anyone have links to a DIY solution to build these?

[Sui_City]

Give these a read and play around with the numbers:

HiFi Speaker Design © mhSoft 2008

A qrd or Quadratic Residue Diffuser. It's a 1 dimensional diffuser based on a prime number.

I'm sure Ethan or Glenn will hop in with more.

[Glenn Kuras]

Sui_City gave you what it is but read the following to understand how it works

GIK Acoustics presents "How Diffusion Works!"

I believe there is a stinky at the top of this forum outlining how to build them.

Glenn

[Weasel9992]

A "stinky"?

Must be jet lag.

Frank

[Glenn Kuras]

Originally Posted by Weasel9992

A "stinky"?

Must be jet lag.

Frank

lol lol lol.. Sorry, "stinky" is how I felt after traveling for 14 hours back from Germany, The brain is a little today from the jet lag.

Glenn

[Jaques Beraques]

Originally Posted by Glenn Kuras

lol lol lol.. Sorry, "stinky" is how I felt after traveling for 14 hours back from Germany, The brain is a little today from the jet lag.

Glenn

Glenn,what did you do in Germany?

[Glenn Kuras]

Originally Posted by Jaques Beraques

Glenn,what did you do in Germany?

Had some work things (more to say later) and

A Little site seeing in Munich!!!!!!!

[Jaques Beraques]

O.K.

The Blond Girl has 2 nice Traps,or are those diffusors?

[Glenn Kuras]

Originally Posted by Jaques Beraques

O.K.

The Blond Girl has 2 nice Traps,or are those diffusors?

Perfect polys!!!!!!!

Glenn

[tomdarude]

Did you try to speak right into them for a quick test, Glenn?

how did they...errr....perform?

[Glenn Kuras]

how did they...errr....perform?

Well it had this VERY nice tone that seems to make you want MORE AND MORE AND MORE. The only problem is that when you speak into them in English it reply's back in German. I will need to do more testing to figure out the reason. OK BACK TO TESTING!!!!!thumbsup

Glenn

[avare]

Obviously a nicely curved high end. Probably a tight midrange and full low end also.

Andre

[Weasel9992]

I don't get it. We're still talking about acoustic treatment, right guys? Guys?

Frank

[Ethan Winer]

Heh, just wait 'til you guys see what I have coming up...

[Glenn Kuras]

Originally Posted by Weasel9992

I don't get it. We're still talking about acoustic treatment, right guys? Guys?

Frank

Yes Frank, what part are you not getting? Opps that could be taken wrong.


Glenn

[Sui_City]

Originally Posted by Glenn Kuras

Had some work things (more to say later) and

A Little site seeing in Munich!!!!!!!

Gotta love the size of those jugs.













Sorry, couldn't resist.

[tomdarude]

Originally Posted by avare

Obviously a nicely curved high end. Probably a tight midrange and full low end also.

Andre

good observation andre!

...though in the long run my guess is, even a nicely kept up pair original Pultecs will do that WAYYYYY cheaper!!



"OK BACK TO TESTING!!!!!!"

Glenn, make sure Ines doesn´t catch ya!!

[Glenn Kuras]

Originally Posted by tomdarude

"OK BACK TO TESTING!!!!!!"

Glenn, make sure Ines doesn´t catch ya!!

No problem, she hates the beer tents at Oktoberfest.