A little spare time and found me playing around with Picasa, imagining up diffusor designs.
Following are drawings of my second conception, which uses a series of round dowels oriented vertically. The orientation of the dowels was more or less arbitrary; I made a pretty design with circles and extruded it.

The rods are 2", 1" and .5" in diameter.
The yellow block behind the rods represents rigid fiberglass, 4" x 24" x 48".

Would this make an effective diffusor?









Piyono

I have no idea without hearing it, but my gut reaction is this will not be a good diffusor. Little chambers behind dowels is not what you want. It's the front surface that determines how well a diffusor scatters sound.

--Ethan

OK, then.

Here's the first idea I had.

The concept is based on this component, an extruded polycylindrical form:



Which is used to configure arrays.
Like this:




Or this:




Again, the yellow textured block behind the arrays represents 2x4 sheets of 4" rigid fiberglass.

Whaddaya think?


Piyono

all the "half cylinder" is of the same size and not so big, causing that if something is diffused, it is only diffuse on a narrow frequency band. The cylinder should be of different size. It is like polys... Exept that poly's can be used as deep bass trap. I don't like the idea of 4" absorption behind it. Too much sound can go through the "diffusor" portion and been absorbed. It could be an idea to put some absorption in some placed to reduce reverberation time, but that's all. Like this, it would not be a very equilibrated field.

It seems like it would be expensive to build,depending on material,kinda looks like a basket weave.

It may be expensive, may not be; the boomerangs could be cast or molded from any number of materials, or they could be cut down from a longer cast or mold.

My intention here, though, is to spark imagination and provoke discussion, regardless of whether these structures will ever be manufactured.

Frank2 says he thinks that too much sound might pass through the boomerang (uh, fishbone?) array. I, however, take the view that this design gives a lot of diffusive surface area, and I think this brings up an interesting question: Does surface area need to be contiguous (that is, uninterrupted) in order to be effective? My own intuition tells me that there's enough surface area on any one of the boomerangs to reflect most of the frequencies you'd want reflected (and if not they could always be doubled up on the axle), while the spacing between then allows the frequencies you want to be trapped to pass through unhindered and do just that. My first instinct is to call a wall like this 100% absorptive and 75% diffusive! Somehow that really appeals to me.

Piyono

I think that if not a great diffuser,it is an interesting,and attractive feature to have in a room.Perhaps not suitable for critical audio applications,but perhaps large rooms like airports,auditoriums,etc..

Here's something pretty inexpensive that is kind of like your second idea: http://www.mioculture.com/store/pc/viewPrd.asp?idproduct=9

I have no idea if they would work well or not, but it would be great to hear Ethan and others' feedback. They sure look cool and would look great across an entire back wall (with bass traps in the corners, of course!). But, looking cool doesn't necessarily mean sounding good.

That's a really interesting product. It's not as deep as the product I have in mind, which probably means it won't work to as low a frequency.

Acoustic properties aside I like that it uses closed-loop, post-consumer waste production.

The sketches above don't really express my vision for control room acoustics.

The design philosophy that really speaks to me is room-wide neutrality; basically making a space as acoustically irrelevant as possible within the confines of what's practical and what is physically possible. I don't like the idea of acoustic 'zones'— LEDE, RFZ and so on.

One room I look at for inspiration is George Massenburg's Studio C at Blackbird studios. Conceptually it's similar to what I have in mind, which is, basically, to diffuse the upper frequencies that benefit from diffusion and to turn everything else to heat. In my hypothetical studio all surfaces are equally diffusive and absorbtive... Sort of.

I'll explain further by way of more images.

i don't think that paper thing is good. It diffuse something for sure but it should not have an interresting bandwith. It does look great. That, again, is only the "technology" of poly's... You will have to learn advanced algebra to be able to create a better diffusor than QRD, in my opinion.

Also just to note, paper will absorb some, which you do not want.