diy skyline diffusors on the cheap

[mahasandi]

you know the wonders of surfing led me to this .

http://www.bobgolds.com/DifuserKgveteran/home.htm

you have to hand it to the guy.

[s.d.finley]

Very interesting.........I wonder if the foam density is a factor in the diffusion scheme.

Anybody try this setup? Ethan Wiener, do you know if usable in a studio enviroment?

[tINY]

For the size of the diffusers shown, the styrofoam should work fine. We are talking about midrange and up with those....



-tINY

[Glenn Kuras]

Oh yea what bob has there will work fine.

[nathanvacha]

i saw a thread based off of that photo like last summer, actually.


seems to me you may want to look for something hard to possibly spray over it.

[Ethan Winer]

Originally Posted by s.d.finley

Very interesting.........I wonder if the foam density is a factor in the diffusion scheme.

Anybody try this setup? Ethan Wiener, do you know if usable in a studio enviroment?

Without being there to touch the material in person it's impossible to say. RPG makes good products, and they make diffusors from styrofoam, so I'd think it's possible anyway.

--Ethan

[RyanPatrick]

That foam is pretty hard. I have carved it with a razor knife for proto modeling.

[BigJunk]

does anyone make budget diffusors that actually work well? like premade? I know Auralex has some but are they equal to foam for absorbing?

[Bob Ross]

While I'm sure the Kgveteran recipe will yield some useful scattering, I'm a bit disturbed by his suggestion to use a "random" dimension for the various depths of the wells. In a true quadratic residue diffusor the depth of the wells determines the low frequency limit of the device's effectiveness, and a uniform distribution of different depths is required in order for the diffusor to yield a flat response over a given frequency range. Those just don't strike me as parameters you'd want to be cavalier about determining.

(edit: or maybe I'm just not giving him enough credit; perhaps he means "random" in the literal mathematic sense, rather than as a synonym for "arbitrary"?)

I also thought QRD's by definition have a prime number of wells; Kgveteran's appears to be a 24 x 24 well grid. I admit I have no idea how this non-prime number will affect the diffusor's performance, I'm just sayin'... (And I could be totally wrong about the prime number thing.)

[big country]

when Im done it will have a canvas logo (almost painting like on the front)
It will have a knob to open and close the slats

[Ethan Winer]

Originally Posted by BigJunk

does anyone make budget diffusors that actually work well? like premade? I know Auralex has some but are they equal to foam for absorbing?

"Work well" and "budget" don't go together well for diffusors because good diffusors are complex to design and build. Also, just to be clear, diffusion and absorption are opposite goals. As far as I know the only product that does both tasks well is my company's diffusor. This is a real QRD design for midrange and high frequencies, and it transitions to bass trapping over the range around 400 to 800 Hz. But this is not a "budget" product either because it's very labor intensive for us to manufacture.

--Ethan

[mahasandi]

Knowledge is power


http://www.mhsoft.nl/DiffusorCalculator.html

the math is important to maximize efficiency so use this calculator.

with the plans for the skyline diffusor link above (Kgveteran's 2D Difuser)

cut the 4x8 in 4's put 6 8" spaced lines on those so you end up with pieces that

make 8 12x12 and this way each panel you cut is based on one slice of the 12x12

model from the calculator.

and eps (expanded polystrene) used in rpg products or xps ( extruded polystrene)

are the same stuff for this application owens corning sells it @home depot.

Additionally spray the finished diffusors with clear laquer and or paint color of your

choice (RPG recomends durex multi purpose paint)

A real paint spayer is best. this further bonds the glued parts for less vibration

between pieces.

and get ready to save about $1500.

well that is, if you have a .............. lot .............. of extra time!

or like me you do a little here and there eventually they'll be done! enjoy!

[stonecutter]

After finding this diy plan I decided to go ahead and give it a shot. It is a very time consuming project. I had a hard time getting the cuts right. It's also a bit confusing to get the math right since each piece creates two "puzzle" pieces.

Has anybody else done this? If so, how did you attach them to your wall?

I had absorbtion on the back wall of my control room for some time due to the fact that it was all I had. I haven't noticed much of a difference yet but I'm still working on a couple other problems in my control room. The room is small (15'Lx12'Wx7'H) and it was built to be an office so there are plenty of issues.

I'll try and post a picture soon.

[mahasandi]

Hey

cool , yeah its a mega work huh?

I have some done .

They sound awesome flutter is spread and rounded into a little reverb and the freq spectrum feels more 'musical' even?

Its a little erie the room does sound bigger and imaging improved.

I have gik traps all over the corners but these skylines for midrange.


Incidently my room's about your size.

You can mount them with glue since they are so light.

Or if you don't want to muck up the walls you can hang them like a picture

with eye-hooks and picture frames.just screw some eye-hooks into the foam

and 1 on the wall or 2 for ceiling.

you could glue glue them to plywood board and mount them if you felt the need.

As for the puzzle its an interesting point

if you use the calculator you should be fine for the side intended but the inverse side?

well I've put them both up together 8 24x24 and not measuring but using my ears,

using mics with omni, now sound great in the room .

and though a little adjusting , at first my speakers have better clarity imaging.

At first i placed one panel in a bare area and wa~la the flutter was gone,

even my girlfriend could hear it!

Also the cheap stryo-foam cutters by wonder cutters STAY AWAY .

they crapped out .They say they are for "styrofoam" not eps so my fault....

it was a lot of fun but took a long........................... time but a good meditation

anyway let me know how it goes.

[mahasandi]

oh yeah i forgot


yeah the cuts were not perfect i'll put up a picture if i can find that damn camera.

but i wouldn't worry about that they work.

I ended up using one of those long exacto knifes that extended.

Heated the blade over the gas stove stop before/after each cut with the exaust fan on

for fumes.

the thicker long blade is easier more true then the smaller long blade i got in a 2-pack .

I was worried about perfect cuts thinking i was screwing up

but listening is the key.

Of course diffusion really is icing and needs adequete absorption.

Small rooms IME work great with diffusion as it evens out the sound.

its not much about the 'reverb' if you can call it that,

as it is about the mid/high freq's that don't get absorped or flutter muddy style.

its a rounder sound fuller

[RichS]

A good quality bread knife (long serrated blade) works well with all types of stiff foam.
( Don't need to heat it! )

[stonecutter]

Originally I tried it with a hacksaw blade. It was very hard to turn the corners. I ended up buying the wonder cutter knife and it worked the best. It did say it was intended for use with only "styrofoam" and not this stuff.

How much wall space are you covering? You mentioned omni mics. So you put this up in a room where you are recording? I just put a 2x4 section on the back wall of my control room. My control room is a pretty serious work in progress.

Next acoustic purchases will be some Owens Corning 703 and some more 2" foam.

[AdamZuf]

Guys, please help me out in the new thread I've opened:
http://www.gearslutz.com/board/low-e...ce-please.html