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DIY 11-well 1D QRD diffuser

RickeyM said:
Michael, do you know or can you point me to the answer of "what-if" the "diffuser" is made 72" tall instead of 48"? I'd really like to make a set of these for my Maggies (MG-2.5's) and it seems like they'd be more effective if they were at least as tall as the speakers.
:scratch2:
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I have run across this info, but don't recall where (buried in one of the many eye-glazing technical discussions about diffusion over at gearslutz, I imagine).

Anyway, unless you plan on standing up to do all your listening (and you're at or over six feet tall) it would be overkill. True, if you position a four foot tall diffusion device a foot off the floor that leaves a foot on top and a foot on bottom that, for a six foot panel, isn't "covered" by the device. But in your seated listening position your ears are likely about three feet off the floor and that puts your head almost in the center of a diffusion zone ....which is right where you want it to be as this is conducive to recreating a realistic sound stage. Adding more vertical range to the horizontal diffusion pattern (assuming your talking a 1D diffuser) really wouldn't be necessary unless your ears are situated toward the top of the panel when you listen. And even if that were the case, you could just move the diffusion device up to the location that put your ears along the device's horizontal center line. Make sense?
 
O.k.

Makes sense the way you put it. Which is a good thing from a $$ standpoint :D This way I can use 2'x8' Styrofoam panels (cut evenly in half) with less waste

I was going to upgrade some power cords & IC's but I think I'll do this first :yes:
 
Now, I should add that I've seen the guys over at GIK acoustics recommend more than two feet of width for a diffusion device behind a magneplanar or ESL. I've read in several other places having the entire front wall covered in diffusion devices or at least a device on the front wall behind each speaker and one in between is preferred. And if you can get at least four inches of absorption behind the diffusion devices all the better. Also stressed in most all of the discussions was the importance of getting a mix of diffusion and absorption on the rear wall, as well. Of course, the distance between your listening position and the rear wall has to be considered when choosing the proper diffusion device for that location. For well type QRD's a general rule is one foot away for every one inch of well depth.
 
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When I started experimenting with this stuff, I built an absorber to go on the wall behind my sofa. Due the size of the room, the sofa is up against the wall behind it so I don't think a diffusor will work there.
The absorber panel is 2ft, high placed at the top of the sofa back and 6ft wide. It does a great job of making that wall behind my head disappear. At the same time I had the entire wall behind the Maggies (MMG's) covered in bubble wrap. These devices actually improved the sound quite a bit. I think with putting the MG-2.5's in there, I'll go with a more "broadband" solution this time :D
 
Ah, yes. With the listening position up against the rear wall the rule for that location is absorption. Of course, you already know that since you've realized positive results with your rear wall treatment.

I'm anxious to see what you and totem wind up doing, Ricky. It appears both of you have a similar approach to the hobby as myself so I'm hoping I can cop some killer ideas off of you two! Definitely wanting to see what happens with the 2.5's as after I'm done with the IRS Betas I'll probably start working on my -IIIa's.
 
Great work on your diffusor I too have been reading a lot about acoustic I have a small listening room that could benefit from some room treatment. I just got some rockwool to make some bass traps.

If you like the Saturn diffusor you might want to check these out not sure of the price I plan to give them a call and see what they go for. http://www.vibrantech.com/products.htm
 
Finished products. Finally. :sigh:

With all the time and labor poured into these things the placebo factor is gonna be off the charts. :yes:

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tomlinmgt said:
Alright, two more done over the last several days. That's three 11-well units and one 13-well unit. Once more 11-well and that completes the diffusion devices for the front wall. I have build time down to about 4.5 hours and have started using more screws than I did in the original design....which helps keep everything square and moving along. I'll see if I can get it down to 4 for the fourth one. This just got fun as hell. :yes:

And I'll be damn if the plastic trash can lids I saw at Lowe's didn't look a hell of a lot like those Saturn diffusers. :scratch2:

Wonder how much math there is in the curvature of the Saturn unit creating a tailored diffusion pattern?
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Hello: I am getting ready to build my first qrd11. Did you miter the back piece or just glue it?
 
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