[terry j]

Originally Posted by Ethan Winer

The three sets of measurement is shown in that video are what's needed:

Frequency Response
Modal Ringing
Reverb decay time versus frequency (RT60)

LOL, I can read you fine. There are so many posts that when I read through a long thread to see if I can contribute something useful, I scan for question marks. If I see no question marks I assume the post is just a bunch of chat and move on.

--Ethan

I think I understand that ethan???????????? ha ha, just testing the new technique!!! (oops, I meant ??????)

Modal ringing, will have to look at the video again and see what that is, I should then be able to do all those measurements, thanks. (????)

Originally Posted by terry j

But in the barker code implementation we would not do that??

Ok, would like to clear this up. I can easily get the barker code (it is in the google books link above, something like 111-111 or whatever)

So, for the -1, all we need do is rotate/flip the qrd?? And for how many repeats do we need this to happen? The reason I ask will become apparent soon.

Ha, just had another look at that book, it seems there is a bit more to the Barker sequence than a set of numbers like that above, it varies depending on the N number....and they list for N=5 the sequence 1,-1,1,1,1. So 'flip' the qrd for the -1's, normal for the 1's???? (?????)

Originally Posted by terry j

So I can conclude that (even with the RPG skylines) that wells seperated by walls is the preferred embodiment? not withstanding that no mention is made of that in the patent? (good for my method)

Am very enthused now to try this this weekend, so a quick 'yes/no' to this question would be great.

More 'stupid' ideas time. Take a fractal qrd, at the bottom of the deep wells we have the smaller qrds, supposedly making the badnwidth greater. Ok then, as I will be trying my ideas on the following type of construction



has anyone ever tried having a smaller pattern in each well?? Rather than a flat face as you see here, think the skyline version of the fractal but applied to this. Again, I think very easy to do with my new method.

Originally Posted by terry j

OR, and this is where we enter fantasy land(?), how about this for a wacky idea? It is about 400 mm deep, may as well add another couple of hundred mm, I could have a bass diffusor 6-700 mm deep, 1350 wide an make it ten foot high or sumthin. Would not look too out of place anyway, due to the natural recess it will be in.

Stupid/useless/pointless idea?? If it did achieve effective bass diffusion, what does bass diffusion sound like? Anyone have experience with that?

No thoughts on this? (?????????? - for ethan hah hah) Proper bass diffusion, does it work and is it worthwhile. (tho I only have 700-800 to play with here)

For no other reason than it has already been designed and tested, I will try and clone this high frequency diffusor for the test

http://www.kineticsnoise.com/interio...true%20QRD.pdf

Dunno if anyone looked at the qrd I wanted to test. I oringinally 'knew' that my trick would work for the type of diffusors I asked about in the first post, but got 'fed up' with waiting for some proven shape, and thought bugger it, I will try a proven qrd design (as in the link above)

Will get some time to take a photo and upload it later today, but yeah the new method worked out well. A couple of aborted attempts as I worked out the methodology...for a short while I had the horrible idea that my idea would not work after all....but then it came good.

I now have a 1.8 m length of the qrd in the link above (of course I can dock/make it to any length I want).

The downside? Well it took longer than I had envisaged (then again the first one always does), about two hours for the completed 1.8 m length.

But the good news? After having done it once, I know that I can make two of them (doing multiples speeds things up!) in about an hour.

Hence my question about the implementation of the barker code.

Hence my curiosity to see if the welled qrd version also lends itself to my ideas.

Originally Posted by Lupo

Hi Terry!

Keep on posting! Will be interesting to see how this project progresses. If you can build appreciable amounts of diffusion and measure the effect as you go, it would surely be interesting for many people to follow.

I, for one, am interested in your speedy diffuser build idea. Have built four square meters of 2D diffusion myself so far and it's going S L O W..

Andreas Nordenstam

Thanks Andreas, much appreciated. Slow eh? how slow??

Are you building a studio?

(Forgot to mention before, I estimate a cost of about $5 or so for that 1.8m length.)

EDIT just plugged the figures 1300 wide and 700 deep into the mhl calculator, threw back diffusion down to 174 hz, 1129 high. BUT, with my technique easy to throw smaller diffusors into the bottom of each well, hmm, bass diffusion may be on the cards! Just for kicks, even if it 'does not work' I will probably try it. Enjoy little learning projects like that.