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abusers Diffusion Products
Old 2nd September 2013
  #1
Gear Nut
 

abusers

So a friend of mine who works at a cabinet shop recently gave me several of these "acoustic panels" that were being thrown out. Unsure about what to do with them, I was thinking about making several 1D qrds based on qrdude specs and fill space behind the wells with some safe n sound that I have laying around. I was going to rip these into strips along the channels and use them for the well faces, if that makes sense, so the slits would allow air to pass through. I mainly wanted to do this as a fun project but also would like to walk away with something functional. My thought was that it would be an absorber/diffuser (abuser). However, after browsing qrd design I've read multiple times that if it is not airtight, which clearly mine would not be, you would essentially have a wildly unpredictable tuned bass trap. Other than the open channels I have the ability to easily make these airtight and I guess I'm wondering if this would be a COMPLETE waste of time/money/resources. I know this is kind of a vague question, but any thoughts on the design would be appreciated. Oh, the qrd would be 7" deep.
Attached Thumbnails
abusers-img_20130902_090934_156.jpg   abusers-img_20130902_091002_420.jpg  
Old 2nd September 2013
  #2
Gear Nut
 

On second thought, from what I understand 7" of SnS won't perform well as a bass trap period, correct? what if I built these as open-backed diffusers with adequate bass traps behind them, all in a single enclosure?
Old 2nd September 2013
  #3
Lives for gear
 
andrebrito's Avatar
 

These are absorption panels, not diffusion.

You would need panels would more serious geometry
Old 2nd September 2013
  #4
Gear Nut
 

I don't think I explained myself well enough. So my idea was to take these panels and cut them into strips along the semi-open channels and use them as the well faces to construct 1D QRD diffusers. So picture an open-backed 7-root well diffusor but the well faces are semi open via the channels already cut into these panels. Then these diffusors would be mounted in front of broadband absorbent material of sufficient thickness to act as a bass trap. (I would also fill the space behind each well with insulation.)

Much like people sometimes face broadband absorbers with reflective surfaces to reflect back some HF, I am talking about facing broadband absorbers with semi-open QRDs in the HOPES that the diffusers would do their jobs with the mid freqs while the bass traps could do their jobs in the lower freqs, all in a single enclosure.....maybe I should draw some pics.....or just try it out

Any thoughts on whether or not this dog might hunt?
Old 3rd September 2013
  #5
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sheggs's Avatar
Are you thinking of something more along the lines of our scatter plates?
GIK Acoustics Scatter Plate - GIK Acoustics Europe
Old 3rd September 2013
  #6
Gear Nut
 

Quote:
Originally Posted by sheggs View Post
Are you thinking of something more along the lines of our scatter plates?
GIK Acoustics Scatter Plate - GIK Acoustics Europe
Well, not really. I figured I could just take these as they are and build them into the front of broadband absorbers to reflect back some HF but my thought was that if I used this material to build full-blown diffusers it would have a much greater effect, as well as being more predictable since I was basing my diffuser design off of the qrdude calculator.

If I cut these into 1 3/8" strips, so the well width would be 1 3/8" inches, I could construct diffusers that scatter down to 400 and diffuse from 800-4kish (I forget the exact freq, somewhere around 3k7) according to qrdude. So I was hoping to create this effect while absorbing the low-end via the partially exposed absorbers in the back.
Old 3rd September 2013
  #7
Gear Guru
 
Glenn Kuras's Avatar
Not sure if I am totally following you on what you want to do, but on the QRD you want the wells to be sealed for them to work. Gaps and so on will lesson the effectiveness of it being a diffusor.
Old 4th September 2013
  #8
Gear Nut
 

Thanks for everyone's responses, my apologies for not being the best verbal illustrator! I think I'm just going to construct one and keep a photo journal, but I figured that I would try to explain once more

Essentially I want to mount, say, a GIK 244 trap on my wall then mount, say, a GIK Q7d directly on top of it (in front of it.) Now, I don't know how the GIK diffusers are constructed, but let's say that the material used for the well faces are only a half inch thick and there is nothing but air in between the back of the well faces and the back of the absorber enclosure. I would essentially remove the back of the enclosure and, say, drill holes in the well faces to allow a certain amount of air to pass through. That's pretty much it.

I uploaded some new closeup photos to better show the panels. On the face, there are 1/6" wide "channels" cut out every 1/2" that are 1/4" deep. Then the back of the panel has the elliptical "holes" cut 1/2" deep. Where the two intersect, there is a hole on the panel.

SO, I was going to cut these panels into strips, construct 1D qrds based on specs from qrdude and use these strips as the well faces so that the wells are partially open to the back where a bass trap resides. Functional abuser?

:D

Sent from my XT907
Attached Thumbnails
abusers-uploadfromtaptalk1378257499076.jpg   abusers-uploadfromtaptalk1378257515983.jpg  
Old 4th September 2013
  #9
Gear Guru
 
Glenn Kuras's Avatar
There really is not enough space left in the back of the wells to really do all that much. Also 1/2" wood will reflect quite a bit, which you want.
Old 6th September 2013
  #10
Gear Nut
 

Quote:
Originally Posted by Glenn Kuras View Post
There really is not enough space left in the back of the wells to really do all that much. Also 1/2" wood will reflect quite a bit, which you want.
Thanks for all of the advice! I take it you are referring to the wells on the back of these panels and not the wells of a qrd, right? The fronts of these are only 12.5% open, the backs probably a little less than that so all in all these are pretty closed off. In general, are these pretty useless? My other idea was just to build open sided bass trap boxes and use these for the fronts as-is (just attatch the flat panel to the front of the enclosure as a "scatter plate" of sorts) to reflect back upper freqs in a less elaborate manner, but would hate to waste expensive material (and time....which I've already spent too much thinking about these things!) if these are simply going to reflect TOO much.

Sent from my XT907
Old 6th September 2013
  #11
This is a cool thread, I admire your resourcefulness. I'm all about DIY projects and am curious how your end design will look and perform. Best of luck!
Old 6th September 2013
  #12
Gear Nut
 

Thanks! I was really hoping to get something useful out of these. The larger ones have a cherry veneer and are especially beautiful. I think I'm just going to have to try it out and hope for the best. I really didn't want to hack up a bunch of 703 into odd dimensions but I suppose they could always be repurposed into odd-sized traditional bass traps if these flop.

Sent from my XT907
Old 14th March 2019
  #13
Gear Nut
 

Only took 5 years but I finally built these. To be clear, I (obviously) have no formal training in acoustics, but rather I was just building out my new room and figured "why not", I've been carrying those panels around for 5 years and three homes. Anyways, I'm not sure of the best way to post build diaries but hopefully these give some idea of the process. Any idea what I can expect from these? Given my nearly nonexistent knowledge of acoustics I'm guessing it's not a great design.
Attached Thumbnails
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abusers-20190224_190440.jpg  
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