Presuming you have access to the required woodworking tools, or know a kind friend who does, I'd suggest looking at the ones designed by the late Terry Cain. The improvement is quite remarkable & have a nice WAF if finished properly. Listed below is a link to the project. http://www.melhuish.org/audio/DIYOT3.html Cheers, Bish |
The diffusers I use are foam version of RPG's. A hot wire cutter can slice these from the pattern of your choice. Mine were built by a local guy and cost was VERY low. Here is a link to them in my system. Click the image to make larger so you can see a little more of it. http://cgim.audiogon.com/cgi-bin/vs.pl?vaslt&1022712214&viewitem&o6 Here are the originals: http://www.rpginc.com/projects/inst.htm |
How about this site for reference: http://www.mhsoft.nl/diffusor.asp#calcul Also, the Auralex metrofusers aren't hugely expensive, but they need to be covered somehow since they are made of Styrofoam and are butt ugly on their own. They are not based on the formula above though. They have varied widths as well as depths. http://www.auralex.com/sound_diffusor_metrofusor/sound_diffusor_metrofusor.asp Lastly, simply PVC tubes might be an option, but there is no real data to support them. Perhaps look up "room lenses" and you'll find something. The room lenses could also be seen as helmholtz resonators too...but I am no acoustician - that I am certain about! |
Albert, doesn't foam act as an absorber? I would think you'd need something harder and more reflective like ABS plastic or wood. Where do you find a hot wire cutter? Foam is softer than wood, but with several coats of paint the surface of my diffusers are quite solid and very effective. Remember, RPG has now opted to offer their diffusers in foam as well. Although mine were created 17 years ago, the idea remains the same. Is there a plan you used to determine the configuration of your diffusers? Also you indicated they were foam, what size foam pieces did you start with? I did not do this, I bought from a DIY guy. My foam diffusers appear to have been copied from the original RPG Acoustics QRD® 734 model. I don't know how he did it, only that they work extremely well, they're lightweight and inexpensive. I'll bet there are places that cut foam packing and such that have a hot wire machine. |
I made my own diffusors using balsa wood. The formula is available online. I bought 2"x2" balsa wood planks online (make sure to specify that they are perfectly square or they may come trapazoidal in cross section). I stained the planks, cut 3 different lengths with a chop saw (over 100 cuts for 30 square feet), sanded and stained the cut ends, and then hot glued them to a set of backer boards. They came out looking beautiful, like a modern art piece (sorry, my system post is not up to date, but if you email me I'll shoot you a photo). It took a long time to make though. Figure 4 hours to stain all the pieces, a day with two people cutting and sanding the pieces, and 2 man-days to do the gluing - if you are covering as much area as me (2 3x5 panels). They work great. If I need more, I may try Albert's system though. |
For anyone looking for Diffusers at a resonable price, take a look at this website: www.waveguideacousticsolutions.com These are 30" x 30" and other sizes are also available. 2.5# density hard closed cell foam blocks mounted to 3/8" plywood and then spray coated with flat black paint(other colors available) It's like DIY, yet the DIY has been done and the price can't be beat! Take a look and you be the judge These are also sold on ebay for a discount price from time to time. . . .check it out, let me know what you think! I'm a DIY guy that knows first hand the high prices of commercial offered acoustic treatments. Hope my offering helps and I hope to be a part of your acoustic treatment solution |
