DIY diffusers...?

[NicolasB]

There has been some talk in the past about somewhat-less-expensive-than-Auralex options for acoustic absorbers. For example, Rockwool slabs compare quite well to Auralex pyramids or wedges in terms of sound absorption, but cost substantially less.

What would be a cheap, DIY equivalent to Auralex's diffusion-based products (or similar)?

How about a solution based on egg boxes and lego bricks?

[pemberto]

NicolasB,
Have a look at http://www.silentsource.com/diffusors-rpg-diffusor.html is shows a different style of diffusors to the Auralex based on a form of MDF.

This would allow a DIY version, but not sure about the cost.

[avanzato]

The Beeb made some as a trial from plastic drain pipe http://www.bbc.co.uk/rd/pubs/reports/index.html.
Decware will sell you plans or a kit for wooden diffusers.

RPG have more interesting designs than Auralex, some you might even be able to copy in Lego!

[The Beekeeper]

Why not try vacuum forming plastic over a wooden template?

[NicolasB]

Any thoughts on diffusers that work at bass-frequencies? Or is this not technically feasible?

[Gary Lightfoot]

Hi Nic,

how did you get on with the rockwool project you were doing? What results did you get (or was it someone else?)

Gary.

[alexs2]

For bass,things like ASC's Tube Traps are most effective,acting as quarter-wave traps.....there are plenty of designs for homemade versions,and relatively easy to make,but not exactly unobtrusive.

[avanzato]

Someone over at Zerogain had a Sound Consultant install eight, 1.3 metre tall, 10cm diameter, 'rubber bung tuned' cardboard tubes to tame the bass. Sounded to me like the Room lens concept.

The cuved surface should give some HF diffusion so several stacked next to each other might be interesting to try. Cardboard tubes aren't expensive and there'd be little or no DIY involved.

[alexs2]

It's a pity that good affordable DSP based solutions to room/speaker interactions are only just becoming available,as it will eventually do away with needing room treatments +/- bass traps etc.

Certainly had something like that been available a few yrs ago when I moved house,I'd probably not have sold the Linn Keltiks I had at that time.

[NicolasB]

how did you get on with the rockwool project you were doing?

Hasn't even got off the ground. Probably never will.

good affordable DSP based solutions to room/speaker interactions... will eventually do away with needing room treatments +/- bass traps etc.

I rather doubt that. In the first place there are directional issues. You may well be able to make a direct sound resemble a reflected sound by playing about with delays and phase changes but it's difficult to see how you could completely simulate (or cancel out) the directional aspect of a reflected sound, as speakers are too close to being point sources - I don't see how you could, purely by electronic means, change the overall shape of the wave front across the room accurately enough.

On top of that, even if a sufficiently ingenious DSP solution could completely compensate for room effects at one particular point within the room, I can't see that there's any way to make it work at all points in the room. Even something as simple as an axial standing wave produces nodes and anti-nodes - unless there is some way to prevent the standing wave from being set up in the first place, I don't see how a solution that produces an accurate frequency response at a node can produce a similarly accurate one at an antinode.

[micb3rd]

Check out this article for cheap DIY room treatments.

http://www.x-bb.org/killahertz/room-treatment.zip

This is the original forum thread for the article.

http://www.talkaudio.co.uk/vbb/showthread.php?t=56300