Quadratic Diffusers

@nonoise - thumbs up for that video. Cheers bro

okay, I was on the same page. thanks

@boxer12 - an interesting idea, one I'd never come across.
It kind of sounds similar to a Binary Amplitude Diffusor BAD?

Has anyone reading this come across a folded well diffuser? Tried them?

@hilde45 - So it's been a few months, what have you ended up doing?

Today I finished the second of four QRD17 diffusers, I used linseed oil and they look beautiful. Next task is placement, and finish off the last two diffuser assembly and oiling. I had no idea that they'd be as heavy as they are.

I am going to try them between the speakers on the front wall first.

Anybody who's got quadratic diffusers I'd like to hear from you as well?

@hilde45 - I had no idea how much I'd need to learn, and the amount of work involved when I took upon myself to have a go at it. I took logs of cherry wood and split them with a band saw, rant them through a thickness planer and joined them to make 17" boards, 5' long.
If I'd not chosen to make them from solid cherry (the backing board is actually Birch ply board) I am sure it'd gone a lot easier.
Running 60 of the 1/4" boards for dividers, 8 sides, 8 tops and bottoms through the CNC router table was easily the quickest part of the job.
It's what I can do now that I've learned, now that's exciting.

Next will probably be the equipment rack.


@boxer12 - I first want to try them between the speakers on the front wall, just the first two for now. I have a frame with absorption, and I want to keep the bottom of the diffusers up off the floor, so I have free space to run cables etc. 

@hilde45 - I was surprised to learn from a good friend and cabinet maker, that balsa is actually a hard wood (by definition).

This is the very first effort making diffusers, and that being cherry wood only. No idea how that would work out, I am surprised that it would degrade though?

I only used balsa wood as a kid, I’d glue wings on a dowel and shape them for lift. Tear apart a golf ball, which was not easy, unravel the rubber band that was under the skin (are they still made that way, I have no idea?) and make a loom from the rubber and use the local park’s slippery slide as a large slingshot to send it up into the sky. Like boomerangs, every now and then losing them in a tree, at least until the next big storm. Other kids would end up with new (to them) toys. Surprisingly light, the balsa planes could withstand a flogging, they fell a long way after being shot up into the air.

** I used the plans I purchased from Acoustic Fields for my QRD17** With a little modifications in the CNC program, the resulting geometry being the same as the plan, just didos are different.

@boxer12 - now I'm even more motivated to get them placed for listening, thanks!

@boxer12 - So I have finally (with help from a neighbour) put them up on a steel frame, about 14" off the floor. They are on either side between and behind the stand mounts on the front wall, 6" overhang outside of the back of the toed in stand mounts.
It's a bit rough and ready at the moment, and all about the sound and not looks, I'm afraid. My wife heard it immediately, it sounds richer.

I have the rear port of my speakers firing directly into some of the deeper wells in the diffuser, the bass is more defined. So much so, I'm really motivated to build the low frequency Activated Carbon Diaphragmatic Absorber. Diffusion is really as good and effective as I'd read.


@Hilde45 - My QRD17 plans were purchased from Acoustic Fields, and I really want to try their absorber I mentioned above, based upon the excellent results my wife and I are hearing.

The sound has becoming fuller and richer from the diffusion, clearer and more refined spacial information as well, compared to just heavy absorption on the front wall.

Wow!  Those really are alien.

@celtic66
Are you meaning the skyline diffusers?
Do yours look somewhat like a scanner barcode? I think they do look modern and clean / sharp. What do you think of their effect on your system's sound?

@tomic601
I trust that an adequate amount of research into good tasting wines was invested in your dual truncated conic wedge diffusers of choice?
Such research done with music, seems like a worthy quest for an enjoyable evening or two..three.. loads of them by the looks of it :-)

but congrats Rix - you already know more than you know…..

Right now, mine do look remarkably like a science project - they do sound great though. And my wife is still ok with it, anyone might think she's becoming an audiophile?!!

Apparently it's what I don't know, that I don't know, that is the greatest potential for improvement.

@boxer12 -  Are you going to try more diffusion between the speakers? Please circle back and share your findings as you move forward. These diffusers took me quite some time, Saturdays mostly, every now and then.

absorption and diffusion are two faces of one entity called 'acoustic optimisation'.

their mutual balance totally determines correct presentation of highly valued musical criteria for reproduction quality:
spatiousness, presence, focus, ambiance, directness, convincing power, non-coloration and dynamic contrast
- Source ReadScaped DIY QRD Diffusers

@boxer12- can you send me a link of an image or page with IRT BAD please?

https://kedap-suara.com/wp-content/uploads/2020/01/panel-akustik-bad-diffuser.jpeg

Thanks tom2015