Acoustic Treatment for Sale, Part 3


Well-Known Member
Dec 24, 2016
  1. No-Name N23 Skyline Diffusers – I purchased two of these (24” x 24”) from a company in California (I can’t remember the name and can’t find the website – I think it might have been through Etsy). These are very effective, in fact maybe more effective than the GIK diffusers. I only purchased two because with the shipping cost, they were just too expensive. I believe I paid around $1,000 for the two, including shipping. I would sell the pair for $500file:///C:%5CUsers%5Ccohnr%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image012.jpg
  2. QD -17 Diffusers - Here is where we get serious about diffusion. These diffusers are designed to go from 225hz – 3,400 hz. This definitely sounds right to me. These never get overwhelmed, even when I am blasting Led Zeppelin. If you have never done so, you really need to hear the improvement in sound from professional level diffusers. Everything is so much clearer and open. Voices and instruments are more solid and locatable. The soundstage really opens up, widens and becomes more three dimensional. These and the QRD 23 diffusers are the single best improvement I made to my listening room (other, possibly, than the low frequency bass traps). The key to effective diffusers (other than getting the depths of the wells absolutely, precisely correct) is to have them as rigid as possible. Vibration will negatively affect the diffusion. So,I built the cabinet and the fins from multi-ply Baltic Birch plywood. This stuff is expensive, but in a completely different league from the crap that you find at Home Depot. The entire cabinet is ¾” Baltic Birch and was put together with Poket-hole screws, Festool Dominos and glue. The fins are ¼” Baltic Birch, glued into grooves in the top/bottom and back of the cabinet and glued to maple wood blocks (used to set the well depths) that are glued and nailed to the fins and the cabinet back. The well caps were nailed and glued onto the blocks. The result is a very rigid diffuser. They have been painted with numerous coats of black lacquer. These things are incredibly effective, but they are large (37” w x 48”h x 16” d) and heavy (a guess is about 100lbs or so). I have 4 of these. Each one of these is a period. Acoustic Fields sells theirs for $2,000 a piece. I will sell mine for $1,000 a piece. file:///C:%5CUsers%5Ccohnr%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image014.jpg
  3. QD-23 Diffusers - These diffusers are designed to go from 185hz - 3,450hz. Their dimensions are 27 ½” w x 48” h x 17” d. As each one is half a period, you need two to make a single period. For these diffusers, I developed a construction method that results in an even more rigid and somewhat lighter diffuser. The cabinet construction and the fins, like the QD-17, are Baltic Birch plywood, put together using pocket-hole screws, Festool Dominos and glue. Here, however, instead of using a series of wooden blocks to set the well depths, I used 2” thick Owens Corning Foamular rigid polystyrene construction board. This stuff is really light, but is very rigid and strong. It also happens to be the exact thickness of the well widths. Aside from the benefit of making things lighter, by gluing the fins to these boards, which run the entire length of the fins and gluing the whole thing, tightly packed, into the cabinet, you get a very rigid diffuser. The cabinets were finished as follows: a spit-coat of shellac, to prevent blotching, a cherry tone dye, a coat of dewaxed shellac and a glazing of darker cherry/walnut stain. Then the units were finished with 5 - 7 coats of shellac. I have 14 (7 periods) of these. Acoustic Fields sells theirs for $3,500 for a period (2). I would sell these for $1,500 for a period. file:///C:%5CUsers%5Ccohnr%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image016.jpg
  4. Real Traps RFZ Panels - These are designed for absorption of mids and highs at the first reflection points. You should experiment on whether the diffusers or the RFZ panels sound best to you at the first reflection point. It really is room dependent. These do a very good job of what they were designed to do and are nice looking and easily mounted on the wall. They are 32” x 42” RealTraps sells them for $270 each. I would sell them for $125 each.

I will try to post photos later tonight. If interested, let me know and I can send you the photos. Also happy to answer any questions.

I am also selling my Evolution Acoustics MM3s, and a Denali power conditioner, so ping me if you are interested

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