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Jakeman1086 · 24th November 2009

Well, I had a lot of fun making my broadband absorption panels, and though I still need to make more, I thought I'd break up the routine by making a qrd diffuser. I loved the sound Ethan Winer was getting in his video recording acoustic guitar with the diffuser. I want that.

I understand the concepts pretty well, and although not completely, I think I know enough to make the panels. I don't care so much about dimensions. I want the panel to be modular so I can tack on as many as I need. Using inverses in Barker's Sequence, I figure I shouldn't have to worry about this aspect.

Messing around with the QRDude calculator and referring to some sites, it looks as if these specs are best for frequencies diffused (correct me if I’m wrong):

23 wells
design frequency = 994 hz

This gives me a depth of 5.35 in, the only dimension I care about. The period will be 25.25 inches.
This only diffuses in the frequency range of 497-6880 hz. To go any higher, I guess I would have to use fractals (I probably won’t do this unless y’all know of an easy method)? For the low end, did I go low enough in your opinion. I plan to absorb the extreme bottom, but should I diffuse lower? Also, how do you absorb behind a reflective surface like the diffuser anyway? Do bass frequencies go through the reflective surface? This concept has never made sense to me.

Lastly, my ideas and questions on building materials and construction - THIS IS THE BIG ONE!:
I want to do it exactly like this guy - N23 Array Build
It seems the most economical (cheap), lightweight, and easy. However, I don’t understand how he put it together and I can’t find anything similar to his method anywhere else on the internet. Did he start with the frame, then just stick the fins in, layering them with the foam? Are the fins and foam actually attached to the frame in any other way than glue? I’d email him, but I can’t find his email address. Please tell me how he went about construction if you know!
Thank you!

24th November 2009	#1
Jakeman1086 Gear maniac Join Date: Sep 2009 Posts: 179 Thread Starter	homemade qrd diffuser Well, I had a lot of fun making my broadband absorption panels, and though I still need to make more, I thought I'd break up the routine by making a qrd diffuser. I loved the sound Ethan Winer was getting in his video recording acoustic guitar with the diffuser. I want that. I understand the concepts pretty well, and although not completely, I think I know enough to make the panels. I don't care so much about dimensions. I want the panel to be modular so I can tack on as many as I need. Using inverses in Barker's Sequence, I figure I shouldn't have to worry about this aspect. Messing around with the QRDude calculator and referring to some sites, it looks as if these specs are best for frequencies diffused (correct me if I’m wrong): 23 wells design frequency = 994 hz This gives me a depth of 5.35 in, the only dimension I care about. The period will be 25.25 inches. This only diffuses in the frequency range of 497-6880 hz. To go any higher, I guess I would have to use fractals (I probably won’t do this unless y’all know of an easy method)? For the low end, did I go low enough in your opinion. I plan to absorb the extreme bottom, but should I diffuse lower? Also, how do you absorb behind a reflective surface like the diffuser anyway? Do bass frequencies go through the reflective surface? This concept has never made sense to me. Lastly, my ideas and questions on building materials and construction - THIS IS THE BIG ONE!: I want to do it exactly like this guy - N23 Array Build It seems the most economical (cheap), lightweight, and easy. However, I don’t understand how he put it together and I can’t find anything similar to his method anywhere else on the internet. Did he start with the frame, then just stick the fins in, layering them with the foam? Are the fins and foam actually attached to the frame in any other way than glue? I’d email him, but I can’t find his email address. Please tell me how he went about construction if you know! Thank you!