Bass Traps and Diffusers for Sale

Music Master

Well-Known Member
Dec 24, 2016
I will be moving to house that will not accommodate all the acoustical treatment that I have purchased over the past 7-10 years. I have been building fine furniture for over 25 years and have a professional level shop, so the treatment I have built is of very high level of construction - in most cases, significantly more sturdy than the similar pieces sold commercially. I am not trying to make a profit, so the pieces are being sold for significantly less than the sale price/cost of materials. I can guarantee you will not find these cheaper anywhere. I am happy to answer any questions or have people come over to my house in Westchester, NY to hear the treatment.

RealTraps MiniTraps (2’ x 4’ x 3 ¼”’) (about 12 of these) -; – These are broad-range bass traps that did a very good job (particularly when mounted in corners and top and bottom) in helping to smooth out bumps and peaks in the 60hz – 200hz range and to somewhat reduce comb filtering hash. I will sell them for $100 a piece. A few of them have some minor damage, but still look very good – I will reduce the price on those to $75. I could ship these, but you would need to

DIY Broad-Range Bass Traps - Similar to the MiniTraps - These are 4” thick Owens Corning 705 rigid fiberglass, wrapped in heavy acoustic (fire retardant) grey fabric. They are 2’ x 4’. Many of them have a mass loaded vinyl membrane. I found these membranes increased the bass absorption and mitigated high/mid absorption. I will sell the traps with the membrane for $60 a piece and the ones without the membrane for $50 a piece.

The Mother OF ALL Broad-Range Corner Bass Traps - For the person with the space and insanity, these really do an amazing job of smoothing things out from around the 60hz range up. They are 4’ wide by 4’ deep by 7’ high. They plywood frames (with ports cut in the sides) that are packed with Owens Corning 705 rigid fiberglass and Roxul SafeNSound Rockwool. The frames come apart and can be reassembled easily. I have used this without any membrane, with a mass-loaded membrane on the front and with diffusers on a small percentage of the front (my speakers have the mids open at the back), I think you would need to experiment in your room to see which sounds the best with respect to md/highs absorption. I will sell these with the acoustic fabric to cover the front and sides for $500 a piece (that is substantially less than the material cost me and obviously does not take into account the work involved in construction).

GIK Monster Bass Traps with Scatter Plates -
These are free-standing broad range bass traps by GIK acoustics.They are 2’ x 4’ x 7”.Like the Real Traps, these do a very nice job helping to clean things up in the range of around 60hz – 200hz. I have two of these and paid $175 for each. I would sell them for $100 each.

DIY Free-Standing Bass Traps with scatter plates – Similar to the GIK Monster Traps, but are 12” deep (they are 2’ x4’ x 12”), which makes them a bit more effective. I built scatter plates for most of the ones I built. They are covered with the same acoustic/fire-retardant fabric I have used for my other bass traps. I have 8 of these and would sell them for $75 a piece.

Low-Frequency Diaphragmatic Bass Traps - I had a pretty bad bass overhang problem in my listening room, with a pretty big peak shown on Room EQ Wizard in the 25hz – 40hz range. This muddied not only the low bass, but smeared the entire presentation. The units I built were sized to fit in the bottom corners of the front and side walls, so the dimensions are 51 1/2" wide x 16 1/2" high x 18" deep. 2 layers of 1” Ranger Board (denser and more rigid than ordinary MDF) for the top, bottom and sides, back is 3 layers. The layers of the Ranger Board are glued together using Green Glue, which is a polymer that really dampens vibration. This mother is solid and sealed. For absorption inside 30lbs of activated charcoal, which is far more effective than fiberglass or rockwool. These result in clearer, quicker, more articulate and more impactful bass, and cleans up the entire presentation. Mids and highs were clearer and more open (much more air) and the soundstage widened and deepened. I am selling all five and would strongly prefer to sell all of them to one person. I am selling them for $650 each, but will sell all 5 for $3,000. This will include the acoustic/fire retardant fabric to cover the whole unit (I never got the chance to pull them out and cover them).

GIK Acoustics Q7d Diffusers. - I have two of these. They are 19” x 46” x 6”. You need to have two of them (a period) for them to diffuse properly, so I will only sell them as a pair. These were the first diffusers I tried and they immediately convinced me of the power of diffusion. I placed them on the wall beind my speakers in the center. Everything, particularly voices became much clearer, articulate and denser. The GIK site says that they are designed to go from 350hz – 3khz. That sounds about right. They can be overwhelmed when playing bass-heavy music very loudly, but they do fantastic things. These units are marred a bit (nothing significant), so I would sell them for $275 for the pair. GIK sells them for $520 for the pair.

GIK Acoustics Gotham N23 Two-Dimensional Quadratic Diffusers - These are two-dimensional diffusers – i.e. they diffuse the sound in all directions. (GIK says they diffuse from 1250hz to 9,500hz) I found that these skyline type diffusers were best for places where I wanted to preserve the air/reverb in the music I used these on the back wall and the ceiling at the first reflection points and behind the listening location. They did a very good job and are very easy to mount (and look kind of cool when you have a bunch of them together). I have about 20 of these. GIK sells them for $179 a piece (plus pretty high shipping cost). I would sell these for $100 a piece and $85 a piece if you buy 10 or more.

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). These are very effective. I only purchased only 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 $500

QD -17 Diffusers - Here is where we get serious about diffusion. These diffusers are designed to go from 225hz – 3,400 hz. 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. 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 Pocket-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 result is a very rigid diffuser. They have been painted with numerous coats of black lacquer. They are 37” w x 48”h x 16” d. 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.

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. The cabinets were finished with multiple layers of dye, stain and 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.

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.


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Hi Again, we spoke on the phone. Are the Q7D blond or unfinished?
how much do they weigh each? What did you use to attach to walls?

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