Making A Quadratic Diffuser From Plywood - Acoustics 

Did this treatment to my audio room a few years ago and it made a WORLD of difference. Did a bi-directional though out of reclaimed wood and because I use bipolar speakers the placement was super critical.

ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-IqBWaXpyad0.html

Haha, funny guy.

Okay, so what he is making is more likely a quadratic residual diffuser. The math is way over most of our heads but the basic premise is most rooms are not designed with sound in mind so they echo badly and those echos ripple back and forth and that lowers the detail of the sound at your ears. Worse all rooms have a harmonic value which means you can actually get a type of mechanical feedback at the right (or wrong) frequency. So, if you understand the math involved you can calculate the wave lengths which are problematic and design passive diffusers which reduce the echos so that the sound reaching your ears is clearer from any given angle. Or at least that is the way I understand the concept.

Agreed. I mean you should be able to expect any question asked IN THE TITLE to be answered in the video.

@@richardtroell6407 Seems like a good hypothesis Richard. Looking at other places for an explanation (which fail miserably in 'lay man' terms). It seems like the halfway point between an anechoic chamber and a very echoey room (like a squash court). Anechoic chambers are the exact opposite of the 'squash court', they deaden all frequencies and sound doesn't sound right or natural. In a squash court you can't talk with a normal voice for the echo. So maybe they're tuning a room to the range of frequencies they want to use.

From the video description and my opening comment pinned at the top of the feed: "I know I didn't exactly say what a quadratic diffuser does in this video, but I did in the project build article: ibuildit.ca/projects/how-to-make-a-quadratic-diffuser/"

@@JohnHeisz Ok, thanks for the link.

I've never seen that stuff before in any hardware store. Silicone, acrylic sealant, extreme high temp silicone, but none of that, weird.

@@Yonatan24 liquid nails

It's not Liquid Nails. Liquid Nails is a different, much less strong adhesive.

@@Yonatan24 Loctite has one: www.loctiteproducts.com/en/products/build/construction-adhesives/loctite_pl_premiumpolyurethaneconstructionadhesive.html

Look for PL premium. It’s good stuff and widely available

I think it's quite obvious that it diffuses, much like other diffusers, but in a quadratic way. You're welcome.

@@keithklassen5320 Rhombohedric sound will become quadratic sound upon seeing the diffuser. Got it.

@@stianyttervik9070 What if I fill it with marshmallows will that help?

@@garyoldham4449 no! You must use circus peanuts to achieve maximum diffusion in a quadratic orientation. Marshmallows will result in a quintuplic symbiosis. Definitely not the effect we are going for here.

Sketched me out for sure

I was waiting for a push bar or a lost finger.

Glad I'm not the only one. Those things scare the bejaysis out of me...

And the push stick was laying on the fence. Apparently it was only used for another video “How to make a push stick you won’t use”.

Here we go again...seek life elsewhere

Hey! I’d love to get a hold of that design plan so I can build some!

Agreed. But I would still have liked to learn something about the principle behind the design.

50" wide - the wall is 14' long. Most 55" TV's are less than 49" wide these days. But then this isn't a home theater. I'll watch stuff down there but it's primarily for listening to music.

They would scatter the reflections vertically if mounted horizontally.

I meant the diffuser height.

Sorry just saw it in the description

Yes, you can, but the dome already diffuses the sound by a quadratic "effect" if the speakers arent centered and they are put close to a side. Maybe also diffused too much maybe...

@@OlivierMyre88 thanks for replying. I'll have to see how it performs once everything is installed.

He peeled the barcode sticker off the plywood. It left behind adhesive residue, which would prevent the finish from adhering correctly. Applying tape with a stronger adhesive, then pulling it off is a common method to remove leftover adhesive.

Kineth1 thanks for that, must have missed it. All the best!

@@erictheviking672 He didn't say anything about it, I just recognized it from when I've dealt with damned stickers.

He was removing the glue left over from pulling the sticker.

Thank you

I've never used any Titebond products, so I can't comment on how they perform. I've used other brands of yellow carpenters glue and that doesn't like cold. It weakens the joint significantly.

@@JohnHeisz How is the yellow glue at pre finished poly glue joints? Or was the PL the only thing that stick the poly together? Thanks.

Woodworking glue only sticks to wood, paper or leather. PL sticks to everything, especially clothes :)

@@JohnHeisz LOL!! Yep!. Thanks John. I'm a metal guy that muddles his way through wood work, so you are a big help!