Diffusion

[Eddie]

Nick, I'm not sure if this is the best place for this thread but I couldn't find a forum in the list concerning recording studios or jam rooms. Please move it to the proper spot if need be.

I am finishing up a studio in my basement and I have started looking into diffusors for the back wall. I have absorption covered using Owens Corning 703's in clouds and wall panels, and I'll have it in the corners for bass traps. All of that is pretty straight forward, but in the realm of diffusion to make the studio audibly larger there are so many options (and costs). Most of these below have an open back where you can insert 703 for low end absorption (below 500 hz) because the diffusor cannot scatter it anyway. But that's not the case with doing the homebuilt version at the bottom. Also, the Space Coupler methodology seems interesting - thoughts?

If any of you have reasearched or know more about which method of diffusion works well please let me know.

Here are some manufacturers.

GIK (http://www.gikacoustics.com/gik_d1_diffusor.html):



Real Traps (http://www.realtraps.com/diffusor.htm):



Auralex Metro Fusor (http://www.auralex.com/sound_diffusor_metrofusor/sound_diffusor_metrofusor.asp):



Auralex T Fusor (http://www.auralex.com/sound_diffusor_tfusor/sound_diffusor_tfusor.asp) :



Auralex Space Coupler (http://www.auralex.com/partscience/spacecoupler.asp):



RPG Skyline Diffusor (http://www.rpginc.com/products/skyline/index.htm):



Here you can see it on the back of a listening wall:



RPG Qrd Diffusor (http://www.rpginc.com/products/diffractal/index.htm):




Here is a home-built. I am thinking about doing this myself, on the entire back wall.



Thanks for any help.

Eddie

[luisma1972]

RPG Sky line should be the best of the list as it acts as a bidimentional diffusor, intead of unidimentional in the case of the others. I'm not shure about T-fusor, for me, it looks more lik an ornament  .

http://www.vicoustic.com/ProdutosCat.asp?cmd=reset&Id=6

That is a european manufacturer, it's cheaper than RPG and made of styrofoam (I guess) or expanded polysterene.

Any way, the diffusors shouldn't be located only at the rear wall, there should be a balance between reflection and difussion on every wall (as a general rule). Most absortion is needed at the points where direct reflections occur for a specific listener position aka engineer/producer place.

[Eddie]

Thank you Luis,

One of the other things I have read is that the diffusor shouldn't be made of any material that will absorb (like foam). It sounds like the Vicoustic may be the same material that those beverage coolers are made of. I think I am leaning more toward hard plastic or wood. I am tempted to do the entire back wall in a home-made skyline diffusor. It is about 135 square feet and I could probably do it fairly cheaply, and maybe even leave a space behind them for 703 panels.

In addition to the back wall I will also have diffusion points on each side wall. In the drawing below the diffusors are labeled D1 and the absorption panels are labeled 242 and 244. Right above the mix desk (bottom of graphic) is a cloud of 242's and behind the monitors will be slightly thicker 244's. The big cloud of 242's is in the live area. The yellows in each corners are floor to ceiling bass traps. Tonight I am installing the track lighting that will go around the big, main cloud. Of course none of this is even going to get me remotely close to Nick's production abilities, but flunkies like me need all the help they can get!

 

[Sharpola]

Anyone manage to make any difusers from scratch and would like to share their tips?
I'd appreciate it for one!

Ray

[Eddie]

Ray - There is a thread on one of the other forums that I go to about building a skyline - I'll see if I can find it. There are also free calculators online that will show you the pattern lengths for each spike on the diffusor.

Also guys, have a look at Blackbird Studio C Control room in Nashville. I believe there are 133,000 sticks. This is John McBride's studio (husband of Martina McBride) and her recording takes place here. Also, in studio "A" I believe the ceiling is motorized so you can raise or lower it to your liking.

http://www.blackbirdstudio.com/

[Eddie]

Anyone manage to make any difusers from scratch and would like to share their tips?
I'd appreciate it for one!

Ray

Ray - This seemed like a pretty good link: http://www.pmerecords.com/Diffusor.cfm

The main thing is that the lengths cannot be random. They use a formula. The more I look at it, the more I want to build a wood Skyline across the back wall. Seems to be the best method, and I can save some bucks doing it myself.

Eddie

[Studioplayer]

Jeezus man. You wouldn't want to fall against one of those walls. You could seriously impale yourself. 

[Sharpola]

Thanks Eddie I'll try that one..

hmmm my music room is 10 by 12 with a window on one side of the 12 and a door on the other, my monitors & sub face the 10 ft way, so all I need is to build one difuser behind me? maybe something different on the other walls?

I'm asking anyone
Ray

Anyone manage to make any difusers from scratch and would like to share their tips?
I'd appreciate it for one!

Ray

Ray - This seemed like a pretty good link: http://www.pmerecords.com/Diffusor.cfm

The main thing is that the lengths cannot be random. They use a formula. The more I look at it, the more I want to build a wood Skyline across the back wall. Seems to be the best method, and I can save some bucks doing it myself.

Eddie

[DoozerDan]

I was telling my Dad about that studio above. He is of the firm opinion that you could do the same thing with egg cartons, and it would work just as well... says the engineer who will go on about how slightly different tool shape (As in, 0.1mm difference in some things) can make a massive difference in how it cuts metal, but says that egg cartons will work just as well on a studio wall for this sort of thing... So is there any really good reason why it wouldn't work?  It'd be great to be able to tell him why it wouldn't (if it does, in fact, make a difference)

Haha   That about sums my Dad up... question everything, especially when it comes to sound quality. I guess he's never getting anything remotely fancy in the way of stereo systems from me. I'll just buy him a trashy $50 stereo from Cash Converters, he'll never know the difference compared an electro static setup.... 

Dan.

[Eddie]

Thanks Eddie I'll try that one..

hmmm my music room is 10 by 12 with a window on one side of the 12 and a door on the other, my monitors & sub face the 10 ft way, so all I need is to build one difuser behind me? maybe something different on the other walls?

I'm asking anyone
Ray

Ray,

GIK Acoustics (http://www.gikacoustics.com) will draw a free plan for you. They did the plan above and it cost me zilch. I did buy a lot of green glue from them for the double drywall walls and I will probably buy the bass traps and wall panels from them. They are also local to me so I may just drive over and pick them up. I am not affiliated with them in any way though. They have just been very helpful to me during this learning phase.

If you are looking for a cheaper option for absorption panels or you want to build your own, I found this site a while back while doing my research: http://www.atsacoustics.com/item--Owens-Corning-703-Case-of-6--1004.html

You can get six 2x4 panels for $86 uncovered if you want to cover them yourself, which I would recommend since it is fiberglass and will get in the air you breathe if uncovered.

One thing I have learned is that "even" rooms (10x10, 10x12, 12x14, etc.) is not a good thing, but it can be corrected. If you look at my mix position in the graphic above and compare it to your space you should get a general idea of things that could help. Obviously a cloud of 2ft. X 4ft. absorbers above you and on the side walls (http://www.gikacoustics.com/gik_242.html) would be good. Along with diffusion on the back and side walls and triangular bass traps floor to ceiling in all four corners. Also the larger 4 inch thick panels on the wall in front of you behind your monitors would help.

Also, here is a demo room they have on their site that you can use to compare to your room. I would just email them to see what Bryan (their acoustician) says.



Hope this helps.

Eddie

[luisma1972]

Eddie, look the skyline lp, they are made of the same material that the ones of vicoustic. I asked the salesman the same question regarding dampening and effectiveness of low density materials in diffusors.

I love this subject, and I must congrat you in the search for a better room. Most of us spend most of our budget in fancy equipment, but omit the MOST important element in the equation, the room. Room acoustics is not an easy subject, but it worth the effort.

[Eddie]

Thank you Luis - You have definately swayed me over to the skyline. It seems like it is the most proven design of them all. It is also something I can easily build myself, and it would be a great project for me and my Dad to hang out together working on. I am still giving the GIK D1 consideration also. And if you click the link and read about the Space Coupler method it seems very interesting also. I've made this same post across 4 or 5 forums that I frequent so I hope I get some good recommendations for these.

Eddie

[luisma1972]

Following one of your links, I saw an article I've read before, and it is a good one. Building a difusor is an easy task, cheaper than the brand stuff,  I dont know.
http://downloads.bbc.co.uk/rd/pubs/reports/1990-15.pdf

very interesting

[meekofnature]

FYI, that really cool pic before...that is Blackbird which is owned by John McBride..but that room is George Massenberg's (audio genius/great engineer/inventor of the parametric EQ).  He did the math for that entire diffusion system.  I was standing in that room the day they pulled the plastic off the walls and revealed it the very first time.  I also got a chance to sit in it with Vance Powell who is one of their house engineers and my boss and listen to a 5.1 version Dark Side of the Moon and some Genesis stuff.  That room sounds unlike anything I've ever heard...the only thing stranger was an anechoic chamber.  Your sense of directional clarity is unlike anything I've heard.  It's a little creepy though, it reminds me of a torture chamber where the walls would close in and crush you to death.

Also, we sold them the console that is shown in that room, but they took it out and put an SSL in.  I'm amazed George even put that Icon in there in the first place.

-Marc

BTW, RPG has the best diffuser technology out there according to our acoustic designer.  The guy who did the acoustics in the last studio buildout I did for the guitarist for Rascal Flatts had those in the ceiling of the drum room and they sounded great and were a huge improvement.  I've also used the Auralex products in some treatment we did for HGTV's studios and that had a much bigger impact than I would have imagined.  Really made the room just sound bigger and more open.