QRD37 Acoustic Diffuser

I hope this is the right place to post. This is the plan for a QRD37 difusser I  build for the studio. (286Hz-7644 Hz). A carpenter made the parts for me and I put them together. A little  more weight that I´d like but I guess it could use lighter wood ( these are cheap DM ).

Units are metric and it could be made any size ( if weight is not a problem  ). The important thing is slot number (36) and depth secuence:

0.8-3.3-7.5-13.3-20.8-30-10-22.5-5.8-21.6-8.3-27.5-17.5-9.1-2.5-28.3-25-23.3-23.3-25- and so on...

The secuence is simetric.

The frame of the difusser acts as slot 0 when you put two difussers together (It´s half the width of a slot) .

It doesn´t draw any current and no soldering parts inside but I thought maybe somebody could find use for it.

A build picture

And how it looks like when done

And a great video about how these things work.

http://www.youtube.com/watch?v=4nzmBhkR4JQ

I did a lot of research into these types of things a while back, and I remember thinking how cool and interesting those things are both to look at and to hear.  They're basically nerd art with function to match the form.  I especially wanted to build one of those diffusers that use the cubes of varying depths.  Then I realized I'm shit for a carpenter and the best I could hope for was stapling some John Mansfield on to some 2x4's...  And honestly I didn't even think I could do that well enough to display it on a wall.  Anyway nice work, I'm envious.

I´m a shitty carpenter too. All the hard work was done for me, I only had to put it together IKEA style
I have  those Skyline difussers at the back wall of the control room: About 16m of 4.5x4.5cms red pine wood each one.Just cut and glued over the frame (no pins needed)

Here it is! I thought I had lost it.
Sorry Millzners, now you´ll have to build one 

I forgot to say that Decware sells the plans for a Quadratic difusser with imperial units. 9.95$ at the bottom of the page:

http://www.decware.com/newsite/diy/decware/Speaker_Plans.html

http://www.subwoofer-builder.com/qrdude.htm



This is very helpful.  It even estimates the weight of whatever design you come up with for just about any material you could build it out of.  It will do 2D OR 3d.

pachi2007 said:

Here it is! I thought I had lost it.
Sorry Millzners, now you´ll have to build one 

Click to expand...

I guess I'm heading over to the hardware store.  My wife will be thrilled when she hears all the power tools and swearing coming from the basement.

Thanks!

Nice information.  I've used real QRD's in different studios over the years and had some build recently due to their over the top pricing in recent years.   

Thanks pachi2007

anyone used the Flexifuser?  seems like it'd be pretty easy to build as well.

http://www.youtube.com/watch?v=DRO1NaSzTVI&feature=related

Just a question about QRD... Not enogh to start a new topic I guess.

I want to know if have to fill the chambers in the back of the QRD or I could let them hollow... I've seen photos of them solid, hollow or filled with fiberglass or styrofoam, I want to know your opinions/knowledge abot this...

thanks.

JS

If resonances/vibrations is your concern, my experience is I had no problem with the qrd own resonance (recording loud instruments or with deep lows) but I had a problem with a couple of loose dividers that vibrated in a quite noisy way ( silicone solved this).
I´d go for it but I wouldn´t use a very dense wool (´cos the extra weight only)

found this tool when digging up info on QRD design:

http://www.subwoofer-builder.com/qrdude.htm

free!

And here is the page to calculate a 2D skyline PRD (which is supposedly more effective than a 2D QRD). Building a few as we speak!

http://www.oliverprime.com/prd/

Dylan