first diy diffuser build. QRD and 2D skyline types for Magnepan system.

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gregfisk

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They made a big difference when I was running dipoles in the room (small Magnepans) I was even using an inverted QRD (basically the packing "opposite" that came with the SRL diffusers) in the center front wall, which also helped. They really helped tame the backwave of the speakers from over powering the small room. Comb filtering and such.

With the KEFs, they still seem to add a bit of depth to the sound stage. The center mounted unit didn't add much, so using an absorber there now.

Thank you for your input, I just got a pair of GR Research Super V's finished which are dipoles. You're the second person that I have read that said diffusers make a big different with dipoles. At what location(s) are you using them, the front wall or side walls?

Greg

S Clark

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That's one heckuva speaker you just built.  One thing I might mention is that when Danny was showing the SuperV's at the RMAF, he always used lots of diffusion, and those rooms always sounded great. 

jk@home

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Thank you for your input, I just got a pair of GR Research Super V's finished which are dipoles. You're the second person that I have read that said diffusers make a big different with dipoles. At what location(s) are you using them, the front wall or side walls?

Greg

Try them on the front wall, also at the first reflection points of the side walls. With my Maggies, I felt polycylindrical diffuser sounded best at the first reflect points on the side walls of my small room.  But QRDs may be better there in your room. Polys are real easy to diy, unlike QRDs.

srlaudio

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Hey guys, I have built a lot of diffusers and tested them all with music.  I recently had a customer from Texas that wanted a duplicate of one I sold him about a year ago.  Amazingly I could not find his design but found another that was close in size that I had never made.  In the process of covering it with Guilford of Maine cloth I was struck by it's performance.  It absolutely sparkled and caused constant grinning as I readied it for shipment.  I would like to point out that this design was created using Schroeder's equations in Excel and executed in high density EPS (unavailable from Amazon, Lowes, Home Depot etc.)  And yes, it also enhances the bass in a very positive fashion.......






bwaslo

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Srlaudio - did you mean "available" rather than "unavailable", or is this stuff different from what Lowes sells?  How do you cut it without getting static-clingy styro particles all over the place? (hot wire?)

srlaudio

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All of the EPS panels sold at Lowes, Home Depot etc. are low density that is 1 lb or less per cubic foot.  I use high density (3 lb per cubic foot) All my panels are made in a massive EPS factory with computer controlled cutting machines accurate to .001" accuracy.  My AutoCad drawings are used to drive the machinery.  I spec the density used and since they are cut from a solid block when I ship the bare ones I ship the whole block (the "negative" or inverse of the panel is included) this offers the best protection during shipping. I have never seen the high density material sold commonly because the low density has better R value for insulation application due to the air bubbles trapped in the material.  Since my material is 3 times denser, it is of course more solid which improves it's acoustical performance.

gregfisk

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All of the EPS panels sold at Lowes, Home Depot etc. are low density that is 1 lb or less per cubic foot.  I use high density (3 lb per cubic foot) All my panels are made in a massive EPS factory with computer controlled cutting machines accurate to .001" accuracy.  My AutoCad drawings are used to drive the machinery.  I spec the density used and since they are cut from a solid block when I ship the bare ones I ship the whole block (the "negative" or inverse of the panel is included) this offers the best protection during shipping. I have never seen the high density material sold commonly because the low density has better R value for insulation application due to the air bubbles trapped in the material.  Since my material is 3 times denser, it is of course more solid which improves it's acoustical performance.

So, the EPS you use is more dense than the pink board insulation that HD sells? From the picture the product looks like the stuff they make coolers out of. It must be much more dense than that thou? So do people use the negative panel you send them as well? It seems like it would also work at diffusing the sound.

bwaslo

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Thanks for the link, Bill.

Look forward to the photo(s) of the back-of-the-room diffusers after you put them together.

Jim

Hi Jim,

I just saw your post (haven't come here very often in the past year), sorry for the late update.  I've done several similar wood diffusers since then, including floor standers and a rather unique focusing diffuser arrangement (sounds like a contradiction, but isn't -- that one is the subject of an article soon to appear in Linear Audio magazine next year).

Bill


There is more about these at http://www.diyaudio.com/forums/everything-else/269366-making-easy-diy-depot-sound-diffuser-panels-step-step.html
 

jimtranr

Nice work, Bill. And appreciate the detailed description and explanation in the link.

Jim

Rob Babcock

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That looks great, Bill! :thumb:

bwaslo

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Thanks!
And happy 2016, everyone.

For anyone near a big hardware/lumber store in USA, that diffuser is almost silly easy to make, nearly all the wood pieces can be bought cheap and already in their needed dimensions, and need only a nail gun (or even hammer and nails) to put together.  Biggest issue is whether you or your Significant Other can tolerate something that large in the room.

gab

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Thanks Bill! I was familiar with Tim Perry's work at Arqen Sonic. But these look amazingly simple and easy to construct. On my list... Happy New Year to you

gab

rand

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Thanks!
And happy 2016, everyone.

For anyone near a big hardware/lumber store in USA, that diffuser is almost silly easy to make, nearly all the wood pieces can be bought cheap and already in their needed dimensions, and need only a nail gun (or even hammer and nails) to put together.  Biggest issue is whether you or your Significant Other can tolerate something that large in the room.

it might have a better WAF if it is covered with cloth - ask her what color and texture she prefers...