first diy diffuser build. QRD and 2D skyline types for Magnepan system.

Rclark · « **Reply #100 on:** 16 May 2013, 05:04 pm »

They are between 9 and 12 feet from me. I built the largest diffusers I could, basically. Have the day off and am meaning to go build soon but I simply cannot stop pulling down cd's. It's"wooooaaaah" all over again. That soundstage and detail is blowing my mind. Not to mention I suddenly have a very meaty midbass.. Lots of changes and a lot to take in. I'll snap some pics tonight too.

edn4x4 · « **Reply #101 on:** 16 May 2013, 06:53 pm »

thanks for the reply - I guess I meant how far from your front wall

I am wondering if I can get them closer to the wall with diffusion since I have a 14' length room and right now about 52" out from the front wall (in your terms) and sit out about 30" in my listening position - doesn't leave much room between my feet and the speakers.

TRADERXFAN · « **Reply #102 on:** 16 May 2013, 07:23 pm »

So what happened to all of those one inch strips I saw on a prior page? I can't recognize them in the pics of the finished project. Are they stacked up? They look like solid pieces in the pictures.

How much did you spend on the foam for the 2 or 3 you are making?

For those who follow a diy diffusor build for posterity...
I didn't want to throw it in the thread earlier, since you had bought quite a few tools by the time I noticed, but they do sell a specific tool for this called a foam cutter. It is a hot wire system. This would give you smooth cut ends. I think there would be no sanding step if this was used.

However, you would need some kind of jig to implement, and ensure straightness and consistency
http://www.amazon.com/Woodland-Scenics-Wire-Foam-Cutter/dp/B0006KSMEU/ref=cm_cr_pr_sims_t
there is bow guide option on this as well.

I planned to do a diffusor project this year and thought about foam, and found this. But have been leaning towards some other options.

-Tony

PDR · « **Reply #103 on:** 16 May 2013, 08:40 pm »

I used a hot wire table....about 55" long and 30" wide...that we use at work when
I built my QRD. To be honest, I think I would just use a table saw next time, it would be
a chore to get straight cuts with a hand held device, I have a number of those as well.

RClark, its good to see that your happy with the results. I know it was a bigger task than
you first anticipated, but I bet you get satisfaction from knowing how well they work
and building them with your own hands. Or perhaps not.....

Rclark · « **Reply #104 on:** 16 May 2013, 09:12 pm »

Yeah, youre right, next ones will go twice as fast.

. Now that I can build em, I can fine tune till cows come home and make different types as well.

And I will. The result has me utterly intrigued by room treatment. This has to be equal if not greater importance than your gear. As you well know, the results are pretty astounding. About to see how 4 of them work!

And now that I really can't hear my rear wall, my eyes are on the front..

Turns out these trap bass too, didn't know that... My Maggies are hitting hard on kickdrums, never would have thought it possible, Can't wait to see what full treatment does for that aspect.

The main thing I'm getting with the two is pinpoint imaging that is just all over my room now, and just incredible dimensionality. Used to be a certain cd that would bring it out but now everything is just like Imax 3D for the ears.

TraderXFAN, I'm ashamed to say most of those 1 inch strips went to recycling. I've saved 4 of the large 2" panels and they are about to become skyline's for my front wall.

Ok..more later. Back to "work"

Rclark · « **Reply #105 on:** 16 May 2013, 10:00 pm »

And for the record, this is nowhere near the same as having some plants or a bookshelf in the way. We've all had plants and bookshelves in our room, this is a dramatically different, purposeful effect. I've never had a stack of random books do anything even remotely close to what these are doing.

If you want diffusion, you need diffusers.

Oh look! Videos!

http://www.youtube.com/watch?v=4nzmBhkR4JQ (those Realtraps diffusers look really really nice.)

and especially this one http://www.acousticsfirst.com/educational-videos-acoustic-sound-diffusion.htm

Ok, almost time for a lunch break. Panel 3 is done.

Maritan · « **Reply #106 on:** 16 May 2013, 10:05 pm »

I'm jealous and impressed all at the same time.

What is the distance between the speakers and your diffusers (at least the ones directly behind the speakers)?

Looks like you built a 23 prime diffuser, correct? What is your well width? And what is the depth of your deepest well?

Thanks! I'm thinking of actually just buying some instead of building it. With a busted knee in rehab, dogs that need attention and a girlfriend that would prefer that I paid attention to her, I don't think I have much time or energy to be building stuff...

Nice work.

Rclark · « **Reply #107 on:** 16 May 2013, 10:09 pm »

Thanks.

Well width and fin width are both 1". Deepest well is 10.62 inches

. About as deep as I can go in my room, according to the experts. The calculator says my listening position is good though, and all I hear is ear candy. I spent all morning listening for anything wierd and nope, all good.

Yes, buy them, the manufactured models are worth it, and on top of that your girlfriend will like them better than my diy model

realtraps.com

gikacoustics.com

primeacoustic.com

acousticfrontiers.com

..just off the top of my head. They are all ready to help you.

Rclark · « **Reply #108 on:** 16 May 2013, 10:40 pm »

Quote from: Maritan on 16 May 2013, 10:05 pm

What is the distance between the speakers and your diffusers (at least the ones directly behind the speakers)?
[/b]

And don't worry, I'll get those measurements too. The best method is to calculate your room with a room measurement device. The only reason I'm going in feet first is it seems a pretty safe bet according to many other users that Magnepans + QRD's against the wall =awesome. Fine tuning will come later.

At this point I would say the speakers are about 3.5 to 4 feet away from the diffusers. It will all make sense soon.

Maritan · « **Reply #109 on:** 16 May 2013, 10:52 pm »

Ok, fine. You got me.

I'm jealous, impressed and impatient all at the same time.

TRADERXFAN · « **Reply #110 on:** 17 May 2013, 01:04 am »

Quote from: Rclark on 16 May 2013, 10:09 pm

Well width and fin width are both 1".

RClark... if your diffusors are the ones pictured, you have no fins!

Rclark · « **Reply #111 on:** 17 May 2013, 01:29 am »

Like I noted in a previous post, it's as though the styro models are just wells. Mine are this type of QRD:

rather than this type:

TRADERXFAN · « **Reply #112 on:** 17 May 2013, 01:40 am »

Not criticizing, just trying to clarify, for others, they don't really match the info that was projected in the modeling screenshots for qrdude that you gave.

Glad they work for you. Congrats.

What thickness backer board did you use? I suspect that has helped your bass, assuming these are not mounted to the wall?

Rclark · « **Reply #113 on:** 17 May 2013, 01:45 am »

I was curious about the backer board as well (.25"). But I don't see how backer board would be better than closet door or.. wall, which didn't have an effect on the bass like this before. Has to be the diffuser.

I can't see this on graph form yet, but it sounds like everything has been flattened out tremendously and this has to be what's improving my midass. Bass is stronger too, and it's that dipole, planar bass, fast fast fast. Found myself turning it down to not disturb my neighbors but found I was averaging under 60dB. Wow.

medium jim · « **Reply #114 on:** 17 May 2013, 04:22 am »

60db is a mere whisper, less than normal conversation.

Jim

Rclark · « **Reply #115 on:** 17 May 2013, 05:06 am »

Yeah I know I've mentioned how my system works well at low volumes before but now it's all even clearer. It sounds far louder than it is with these in place, especially the bass now, apparently, not measured.

Almost done. Been taking my time with these last two. The inverse panel is slightly more difficult with more very low walls meeting very tall ones.

Rclark · « **Reply #116 on:** 17 May 2013, 11:37 am »

Oh boy am I tired. Stayed up late finishing these.

My room isn't quite ready for prime time and I need a better camera for that, but here's a shot of the full diffuser. As you can tell, it's monstrous.

That's John Coltrane's "Giant Steps" for size reference, CD. Well, about to put on something relaxing and pass out.

Next up for these will be trimming the tops and sides, sanding, filling any cracks with some sort of hardening putty I guess, primer and paint. Once all that's done and I have a better camera I'll take a proper photo of my room.

They are 3.5 feet behind my speakers by the way, and nearly extend completely wall to wall.

jtwrace · « **Reply #117 on:** 17 May 2013, 11:51 am »

Great job!

Next step, buy a measurement device. Seriously.

Rclark · « **Reply #118 on:** 17 May 2013, 06:23 pm »

Thanks Jason

And roger that. Think I'll just buy a mic and a soundcard and do REW. Really interested in seeing this on paper. And for now, on to the skyline build.

I'll post more impressions of the full diffuser later, but nutshell: WOW! Go science!

Rclark · « **Reply #119 on:** 18 May 2013, 06:22 am »

Here's a better perspective of the raw, unfinished build, next to my right speaker. Am loathe to take room pics though until the room is finished and I have a better camera. This one simply does not capture the color and details in my speakers. and it's fuzzy.

Anyway, now you have a better idea of where things sit at the moment.

On listening, beyond what I've said before, the effect really is like being in a much larger (enormous) space. And whatever noise floor or distortions caused by the room itself have either been destroyed or greatly attenuated. I didn't think it was possible to lower the noise floor any further, but there's all sorts of "noise" it seems.

Harmonies are so beautiful now. Vocals are a real treat. Now I can REALLY hear all the studio effects, and really really hear the differences in recording quality.

The effect on resolution is just incredible. I'm extremely familiar with my gear at this point. But last night I was listening to a song that had an electronic beeping in it. All this time it was a beep. Now with the diffusers in place, I can hear that that tiny delicate sound was no beep at all, it was a word being spoken, compressed and whatnot, but an actual word. You think you've heard as far as you can into the mix, but now more is unearthed. All the delicate little parts in the music are now so clear and dimensional, laid out in space before you all as though from their own source.

They must be absorbing some bass too, something's going on, because my bass is out of this world, and very stout. I can't see it in graph form yet but it's obvious to the ears that everything's been flattened out tremendously.

I don't think I can ever go back to an untreated room, this is way too cool, way too large a sonic improvement. Only forward now, more.

Before upgrading speakers or equipment, you all should give aggressive room treatment a consideration. Forget cables and wires, do this first.