My home made diffuser

[MSR74]

Gator Board is used mainly used fr large business prsentations, trade show backgrounds for advertisement, etc. The reason it's used mostly in these settings is because it is extremely lightweight for transport and very durable, almost as durable as wood.

I will give you a couple of websites where I have found it here in the US and doing a search on google may yield some results for you in France. I've also found out that some companies that supply it will cut it to size for a little more $$ than the actual cost of the board, eliminating the need to cut it.

Here's a link and they DO ship internationally. They even sent me a sample so I could see if it would fit my needs.

Gator Boards

Gatorboard by the sheet or case

The second site only ships to the US and Canada, but it gives a very good description of the product and it should be able to be obtained from a large art supply store in France, although as you've suggested they may have a different name for it.

I would suggest contacting artsupply.com and obtaining a sample of it.

Good luck...hope this helps.

[dr jazz]

Thanks a lot for thoses links.
For the resonnance I forgot to say than in each cavity there are two
spacers of 19mm Mdf nones of the cavity has the same volumes .And these volume are not so big...

[andrebrito]

This is the QRD diffusor, from my company, currently selling in Portugal and Spain.It is similar to yours... we have not used MDF but another type of wood (can't recall the name in english !). I expected to test this in an official lab in the UK

[jeremycox]

Finally got to the point of building big diffusors for my studio in Dallas. 8 all together. Just over one days work with a table saw and proper tools.




Sorry for the Iphone photo quality.

Jeremy Cox

[wesarvin]

OK... I couldn't find Gator Board easily yet, but have found foamboard in the craft section of Wal-Mart. I'm building a QRD right now according to this thread's original plan and will post pics soon!

Any predictions of its effectiveness?

[Yetti]

I built these based on specs from a friend of mine who went to Columbia College for sound engineering.
I used to be a custom cabinet maker by trade...I do some side work if anyone was interested in a quote for custom diffusors like these.
Diffusors make a big difference in a room!

[Mihaly]

Yetti,
Can you post dimensions?

Cheers,
Mihaly.

[jeronimo]

Hey Jeremy,

I think I´ll build my diffusors just like you did...

No problems leaving the "inside" of the diffusor empty?

Should I stuff it with rockwool?

[Cloth-Ears]

Another question relating to these diffusors:
Will it effect the diffusion if I cover the diffusor with thin material (for purely asthetic reasons), like a bed sheet?

[crowflier]

yeah i would like to know if theres anything behind the cavities?

i plan on building a few.

what do people recommend for my control room? the dimensions are
9'6" x 12'6" x 12' (thats width, length, height)

i need to properly treat this room.....

thanks!

[Pchicago]

Nice job to the OP.

I'm learning this room treatment and watching you guys here, what a bunch of craftoids you guys are...I'm extremely impressed.

I believe the OP's material is otherwise known as Tempered Masonite?...hard to tell from the pics but i think that's the stuff.

Gator board should be available somewhere in France..Paris art stores etc.

Warning: If you get your stuff cut at Home Depot or any of the large housing supply stores in the USA..beware of getting cuts that are in no way accurate or squared up...beware.

Those large rack mount saws take tons of abuse, are usually out of calibration and the operators don't take enough care in setting the measuring guides...you will end up with a bunch of strips that won't fit together as nicely as you might like them too..I spose you can make up the differences but if you want a nice neat job you might be disappointed..then again, you might get lucky.

I'm watching you guys so make me happy with lots of cool projects and when I start to plan my room treatments I'll ask lots of questions..

Peace!!

[johndykstra]

In response to a few earlier posts,

don't cover the face with fabric, it will make it less effective at high frequencies,

and yes, you should fill the cavities with rockwool or something similar to prevent the "boxes" from resonating

[Tom H]

Here is a picture of one of the high freq QRD's I just put together.



I am also building some skylines wich you can checkout overhere.

[bibleboy3]

dimensions anyone???

[inlinenl]

Originally Posted by Tommylicious

Here is a picture of one of the high freq QRD's I just put together.

Attachment 108106

I am also building some skylines wich you can checkout overhere.

very nice Tom ..... what are you up to ....

[Tom H]

Thanks Wim, I am treating the studio with some different types of diffusers and low freq absorbtion at the moment. I am trying to make the liveroom / vocalbooth as adjustable as possible, so most of the diffusers will be hanging on hooks on the wall and there are rails of curtains to tame down the room if necessary.

Building stuff like this somehow relaxes my mind! thumbsup

[bibleboy3]

how about using luan its cheap $8 for a 4'x8' sheet... also how do you determine the depth of the unit??



Bill

[Tom H]

Originally Posted by bibleboy3

how do you determine the depth of the unit??

You will have to calculate the dimensions in your design with software, you can build diffusers for specific frequencies. I used this.

mh-audio.nl - AcousticCalculator

[inlinenl]

Originally Posted by Tommylicious

Building stuff like this somehow relaxes my mind! thumbsup

I know Tom, I miss it .. maybe I should get a nice scale model off a spitfire again ...
looks good your diffuser

[jhbrandt]

Guys,

jeremycox, I love your qrd. It should work ok.. be sure to place some damping material in the empty spaces.
(I have actually succeeded in making excellent qrds with foam board. :D like Formular 150. - but I used 1 1/2 inch board and made the wells 1 1/2 inches wide.)

The home-made QRD should be at least 8 inches deep.. That way you get diffusion down to 848Hz - with 1 1/2 inch wide wells.. you get excellent diffusion up to 2.26kHz. But your 4 1/2 in depth and well width of ?? 2 1/2 inches will only give good diffusion from 1.3kHz to 1.5kHz.

Yes, you will notice a nice change talking in front of it. And, yes, it will improve your room. But if you are going to put time and effort into this, why not really make it good?

Using MDF or similar you will get the best response as a strict diffusor due to the material being non-resonant and having a low absorption ratio.
You could use aluminum coil for the well dividers - found in the roofing section of stores like Home Depot and Lowes. Spray paint with a latex wall paint to finish.

I have uploaded an Excel spreadsheet so that you can calc ANY QRD you wish and look at the calculated freq. response. This spreadsheet will give you all the measurements you need to build one.

---> http://jhbrandt.net/QRDArrays.xls

I really appreciate what you are doing. The QRD diffusor is the best thing you can do for your studio... even if it's only the ones that jeremycox has done - Great job, Buddy.

I could go on and on about the horrible dead rooms that I have had to work in.. omg. but i wont.

Good luck everyone building these! Build a BUNCH of em.. use them in every room.. not just the CR. You can even get away with using a small booth for recording.. and actually KEEP the recording.. if you fill the booth with QRDs. They are a wonderful and much overlooked tool in the acoustics designer's arsenal.

Remember, commercial products are designed for (in this order).. looks, price, functionality. When you build your own.. you can put functionality on top. :D

[nomoreflakes]

Originally Posted by jhbrandt

Guys,

I have uploaded an Excel spreadsheet so that you can calc ANY QRD you wish and look at the calculated freq. response. This spreadsheet will give you all the measurements you need to build one.

---> http://jhbrandt.net/QRDArrays.xls

many thanks for this tool, really appreciate it. could you give us a quick low down on how to use it ??

best wishes

[vonrichter]

Any chance for detailed plans with dimensions for any of the DIY diffusors on this thread?

[Mulmany]

Use excel or open office, and download the QRD spread sheet above, type in the dementions that you have space for in the yellow boxes and it will give you the well sequence and the Top and Bottom freq in its effective range.

hint: use a narrower width then you think you should and make them as deep as you can afford.

[notyetfamous]

Hey man, Havent seen you in a few years since the GC days at Northcross. Hope things are well. I was hoping that you could somehow send me the designs for these diffusers??? I just had a big project fall into my lap and i want to try these guys out. Shoot me and email and Ill give you my new number so we can catch up. Notyetfamous@msn.com

Thanks!
Craig Sadler
Austin

[bassmosphere]

Originally Posted by jeremycox

Here in NY Home depot charges $1 for each cut beyond two. You can rent a table saw for i think 40 dollars a day--maybe the best bet for someone w/o tools (at least up here).

The best bet would be to buy a bench saw, for about $100 you can get a cheap Ryobi at Home Depot. You get what you pay for, but it is nice and portable and totally fine for this application. I've had mine for around three years and made thousands and thousands of cuts with it and it's still going strong.

[Guitar Zero]

Here's some 2D and 3D diffusors I made. I had fun trying to make them look more artsy.

[RKrizman]

Those look fantastic. Can you share your plans or construction techniques? In the third picture are those just 2 x 2 's (or 1 x 1's) cut to different lengths and glued together?

Thanks,
R

[holger]

hi .. just looking for some good ideas on diffusors ... thanks for the pics .. looking great !!

[Guitar Zero]

Originally Posted by RKrizman

Those look fantastic. Can you share your plans or construction techniques? In the third picture are those just 2 x 2 's (or 1 x 1's) cut to different lengths and glued together?

Thanks,
R

The skyline diffusors are 2x2's cut to a specified length according to the pattern and gorilla glued to a thin piece of plywood. Each length is stained a different shade. They are HEAVY, and a little hard to get up on the wall, but I'm pleased the way they turned out. Here's the formula for the pieces of wood if you're interested: Next time, i think I'll try balsa wood.
PME Records QRD Diffusor Construction

[pultech]

Originally Posted by Guitar Zero

The skyline diffusors are 2x2's cut to a specified length according to the pattern and gorilla glued to a thin piece of plywood. Each length is stained a different shade. They are HEAVY, and a little hard to get up on the wall, but I'm pleased the way they turned out. Here's the formula for the pieces of wood if you're interested: Next time, i think I'll try balsa wood.
PME Records QRD Diffusor Construction

These are neat!
Why couldn't you make something like this out of a medium density foam. It would be light and easy to work?