really great short vid showing a diffuser in action

Rclark · « **on:** 19 Oct 2012, 12:18 am »

in this case a 2D...

http://www.acousticsfirst.com/educational-videos-acoustic-sound-diffusion.htm

good site overall as well.

rjbond3rd · « **Reply #1 on:** 19 Oct 2012, 12:36 am »

That's fantastic!

Rclark · « **Reply #2 on:** 19 Oct 2012, 12:44 am »

I thought so, it's one thing to read about it, it's another to see it in action.

Big Red Machine · « **Reply #3 on:** 19 Oct 2012, 01:40 am »

Very nice and effective to see this in action.

ryno · « **Reply #4 on:** 19 Oct 2012, 03:14 am »

A little misleading isn't it? Sound waves directly at a diffuser like that wont scatter like that, they will bounce straight back up, only at different times. The big balls hitting the edges of the wells and scattering isn't what sound waves will do, unless the tops of the wells are angled.

Rclark · « **Reply #5 on:** 19 Oct 2012, 03:26 am »

Nope, they actually will scatter in all directions.

behold (in this case with a 1D diffuser, horizontally scattered only)

http://www.youtube.com/watch?v=L-qn6ioYuEc&feature=channel&list=UL

ryno · « **Reply #6 on:** 19 Oct 2012, 03:37 am »

That's much better than the silly balls.

Rclark · « **Reply #7 on:** 19 Oct 2012, 03:40 am »

Not really, the silly balls prove it, quite dramatically.

ryno · « **Reply #8 on:** 19 Oct 2012, 03:47 am »

The balls are dramatic, but they are just bouncing off the edges of the wells , sound waves aren't doing that. As I think about the second video the guy depicts sound waves as a snake like line, and the angle of contact with the back of the well causes scattering. Maybe the more physics educated can help me, but aren't sound waves alternating high and low pressures, not left to right vibrating waves? I'm having trouble visualizing it.

Rclark · « **Reply #9 on:** 19 Oct 2012, 04:18 am »

Look here

http://www.gikacoustics.com/video_basics.html

go to 1:54 in the video, even Gik accoustics shows the exact same phenomena as a computer graphic. That's how a diffuser works, scatters and diffuses, either in 1 dimension or 2.

jimdgoulding · « **Reply #10 on:** 19 Oct 2012, 04:45 am »

ehow.com has instructions on making your qwn.

Rclark · « **Reply #11 on:** 19 Oct 2012, 06:44 am »

can't forget this one

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

Nuance · « **Reply #12 on:** 30 Oct 2012, 12:48 pm »

Quote from: Rclark on 19 Oct 2012, 12:18 am

in this case a 2D...

http://www.acousticsfirst.com/educational-videos-acoustic-sound-diffusion.htm

good site overall as well.

Good find - thanks for this.

django11 · « **Reply #13 on:** 2 Nov 2012, 12:02 am »

Quote from: jimdgoulding on 19 Oct 2012, 04:45 am

ehow.com has instructions on making your qwn.

I made one of those using the pattern here: http://audioundone.com/do-it-yourself-acoustical-treatments

nwboater · « **Reply #14 on:** 3 Nov 2012, 03:23 pm »

Quote from: django11 on 2 Nov 2012, 12:02 am

I made one of those using the pattern here: http://audioundone.com/do-it-yourself-acoustical-treatments

Thanks for the link. Would you mind telling us where in the room you located it and it's affect? Do you think more than one might be beneficial? And last, how long did it take to make?

Rod

ptmconsulting · « **Reply #15 on:** 4 Nov 2012, 07:58 am »

Just finished building these for myself. They seem to work quite effectively placed on the front wall behind my speakers.

django11 · « **Reply #16 on:** 4 Nov 2012, 12:02 pm »

Quote from: nwboater on 3 Nov 2012, 03:23 pm

Thanks for the link. Would you mind telling us where in the room you located it and it's affect? Do you think more than one might be beneficial? And last, how long did it take to make?

Rod

It took about two hours to make. You want to have a really good plan on how to hold the little pieces in place. I made an exterior frame and put pieces in the empty spaces while the glue dried. It still came out a bit out of square or warped (maybe both!). I might use nails/screws through the bottom on the next one. Still looks cool though.

The rest of my comment is very uninformed opinion. I just made one very small one at one foot by one foot. The effect of it is marginal. I will make at least one larger one. My plan is to put it in front of my flat panel tv when listening to music.

edit: wasn't fully awake when I wrote that.

nwboater · « **Reply #17 on:** 5 Nov 2012, 01:08 am »

Quote from: django11 on 4 Nov 2012, 12:02 pm

It took about two hours to make. You want to have a really good plan on how to hold the little pieces in place. I made an exterior frame and put pieces in the empty spaces while the glue dried. It still came out a bit out of square or warped (maybe both!). I might use nails/screws through the bottom on the next one. Still looks cool though.

The rest is of my comment is very uninformed opinion. I just made one very small one at one foot by one foot. The effect of it is marginal. I will make at least one larger one. My plan is to put it in front of my flat panel tv when watching music.

Thanks for the feedback. Yeah, it's hard to imagine that 1 square foot could accomplish much - I would think they need to be substantially larger. But you learned what's involved in building on so the effort was not wasted.

Please let us know here the results of your next one.

Cheers,
Rod

mrlittlejeans · « **Reply #18 on:** 5 Nov 2012, 01:54 am »

Quote from: ptmconsulting on 4 Nov 2012, 07:58 am

Just finished building these for myself. They seem to work quite effectively placed on the front wall behind my speakers.

Those look good. did you follow a plan and, if so, can you post a link to the plan?

PDR · « **Reply #19 on:** 8 Nov 2012, 10:45 pm »

Dont forget about QRDude....its a great free download.
Made my QRD (avatar) out of styrofoam and a couple days on a weekend.
I had a poly before, this works much better, well worth the effort.

Perry