Welcome, Guest. Please Login or Register
Decware Audio Forums
03/25/19 at 14:57:00 


Pages: 1
Send Topic Print
Hello, and heaps of diffusion questions! (Read 3298 times)
terry j
Ex Member

Hello, and heaps of diffusion questions!
07/30/09 at 02:51:35
hi all

have just found this section of this forum, and I like the 'emphasis' on diffusion.

Just a quick hello for now. Trouble is, for whatever reason, that the forum is slow and seems to not be as active as it once was? Which if true is definitely a shame.

Just thinking about it, it would be silly to not ask questions or get the ball rolling.

OK then, one of the things (this will be all diy BTW) I want to investigate is the BAD panels binary diffusion/absorption technique. I understand the basic principles behind it, and was delighted to see that one of the more informed contributors here (cannot see his name as I type this, so apologies) has them in his room, and they look great-hopefully work well too I might add!

It cannot be a random series of holes etc, so I have been trying to confirm the correct sequence of ones and zeros for the experiment. Have tried googling a binary sequence calculator, not much luck (seems the computation required is enormous??)

Have been wondering if I need to pay a visit to the mathematics department of the local university ha ha, which explains my 'delight' to see here that someone has built a bad panel for themselves.

(sorry for the inability to give user names right now!) Can *he* provide either a link or a method to get the correct binary sequence please??

More questions  to come, but I guess that depends on whether or not this forum is active?

I really hope so, and would like to be able to give whatever help I can by my own builds.

Fingers crossed, hope to talk to you all later.
Back to top
  IP Logged
Seasoned Member

Posts: 309
Re: Hello, and heaps of diffusion questions!
Reply #1 - 09/05/09 at 22:41:06
Hello Terry,

I just saw your message today, as I don't get onto this site much anymore due to life's demands for other priorities. I had planned to post the information that you are asking for here, as I already have it mapped out in proper sequence and detail.  

You are far better off making a few of these binary diffusers over any other design, as these are more efficient with broader performance.  This newer technology greatly out dates the older designs based upon Quadratic Residue Sequences.

The real beauty is speed of replication and much better aesthetics in the room .  You simply take the dimensions down to a CNC shop and tell them how many duplicates that you need.  They should be cut from 1/8th inch hardboard or mdf if you can get it.

You go to Lowes to get the high density acoustic sections which gets stuffed in the back behind, and tightly against the rear of the plates.  Just a matter of building simple frames to the correct depth with supporting backs to keep it in place.

As for finding someone at the university with the knowledge of this binary code....don't count on it as it was developed specifically for RPG using very sophisticated programs to crunch the numbers. That is patented for them so this is not general information to the public.

The logical thing was to take known parameters and recreate the sequence. After mine were made, I discovered that there is an error in the pattern sequence which is minor, but enough to alter the function of the design.  I have corrected that mistake for updated conversions, to form a workable blueprint. I have since come up with a second design based upon a variation of these binary calculations.

The sequences are drawn out and crudely mapped. They just aren't presentable for web posting yet(and perhaps it is not wise of me to do that anyway).

Since I do not profit from this time and effort, I just don't feel the need to go to these lengths at this point in time, for which many just steal the information for their benefit anyway....so what's in it for me??   Just use common sense with a bit of intellect, and you should be able to do what I did in the application.  Just remember, the final sequence and layout has to be exact, or the end result is not going to be worth the material used to build it.

You may be able to get this code from me in private.  I am not making any promises.  When I get the time and ambition to do so, then perhaps I shall share some of these details. My mind is far from the audio realm these days, so it is a bit difficult for me to stay focused upon it at this time. I am generally careful about who I open up with these days...have fun!

Back to top
  IP Logged
Pages: 1
Send Topic Print