Poor control room dimensions due to amount of gear!

fbars · Post by **fbars** » Sat Mar 27, 2004 1:12 pm

Hi to all... GREAT forum!

Due to the size of the console, and the "excessive" amount of rackmount gear, I've been forced to make the control room at what I believe is considered a poor ratio. With finished walls, the height is 7 ft. 10 1/2 in. the width is 11ft.9 1/2in,with a depth of 16ft. 7in.

My thought for room treatment are to use up to 2 feet(depth) and completely treat the rear wall with broadband absorbtion, no slots. The front wall I plan to use John's corner absorber designs. I'm very undecided as to how to treat the front wall between the corners.

As far as the side walls go, on my right side is the "wall of rack gear" and on the left,the sliding glass doors into the tracking room! Probably not a lot I can do here!!

John, Steve(knightfly) or barefoot, am I going in the right direction or totally lost??

Thanks to all who reply!!!
Tom

dymaxian · Post by **dymaxian** » Sat Mar 27, 2004 2:51 pm

How much wall space is on those side walls? Is the sliding glass door right next to the mix position, or slid forward or back?

I'm thinking about the sidewall reflections... if the door is right next to you, you're ok because sound from the speakers that hits those glass doors will go past you and (hopefully) get caught by your rear wall absorber. If these doors are slightly ahead of the speakers, you might have trouble there.

On the same token, try to place the huge rack-o-gear aligned with the mix position, across from the doors. Yes, it'll goof up sound for people standing behind you, but if it comes down to them-or-you, well... whaddya do?

With good absorption in the front corners and back wall, you should be ok. What's the ceiling treatment like? Absorptive or diffused, or just flat reflective (hope not)?

Kase
www.minemusic.net

fbars · Post by **fbars** » Wed Mar 31, 2004 1:21 pm

Hi Kase,

Thanks for the reply. At the moment there's nothing on the ceiling, I do plan to hang a "cloud".

As far as your question about the doors, they start approx 2 inches behind where I sit. The racks will also be in the same location.

I posted this at the design forum, because I wasn't sure if it was a "design" or an "acoustics" question.

Thanks again Kase, for the response, all input is greatly appreciated!!

Tom

dymaxian · Post by **dymaxian** » Wed Mar 31, 2004 1:32 pm

As far as your question about the doors, they start approx 2 inches behind where I sit. The racks will also be in the same location.

That's even better. All the hard reflections off them will go past you.

Hey Steve, if you're reading this, I just had a thought... would a rack full of gear count as a decent diffusor, even if just for high freqs? I mean, with all those odd knobs and lights and switches and stuff, it's a pretty irregular surface...

Anyway, as far as the side walls go, you've probably got some room left on the side walls for treatment. Just make sure there's something absorptive wherever the reflections from the speakers would be coming at you.

Good luck!

Kase
www.minemusic.net

VSpaceBoy · Post by **VSpaceBoy** » Wed Mar 31, 2004 2:23 pm

dymaxian wrote: .. would a rack full of gear count as a decent diffusor, even if just for high freqs? I mean, with all those odd knobs and lights and switches and stuff, it's a pretty irregular surface...

It seems to me like the front of the gear would diffuse, but what kind of rack is holding the gear? If its open then you'll have all the flat surfaces of each piece of gear reflecting straight back up <slightly diffused> towards the mixing position. If its a cabinet then much worse.

If there is some reflection there aiming back up then you'll want to think about building a corner absorber.

Just my thoughts.

Ron

knightfly · Post by **knightfly** » Thu Apr 01, 2004 1:53 pm

"Hey Steve, if you're reading this, I just had a thought... would a rack full of gear count as a decent diffusor, even if just for high freqs?" -

Probably a little, at around 8k and up - mainly, the down side would be screwing up the rest of the frequency band. That's why you see "producer's desks" behind the mix position that are no more than about 36" or less. The early reflections are NOT your friend... Steve

knightfly · Post by **knightfly** » Thu Apr 01, 2004 2:22 pm

"My thought for room treatment are to use up to 2 feet(depth) and completely treat the rear wall with broadband absorbtion, no slots" -

Tom, if you have that much space available at the rear you can do a pretty decent "gradual impedance" sort of trap - Phillip Newell diagrams one on page 171 of his book, "Project Studios, A More Professional Approach" -

Speaking of diagrams, it would make things MUCH easier if you could post one of your floor plan, with the items marked that are taller than 36" - otherwise, I feel like I'm answering things like "what kind of vehicle should I get", not knowing whether I'm talking to a truck driver, a housewife, with or without kids, whether or not a farm is involved, horses or pigs to transport, planning to first learn how to drive and then winning the Daytona, etc.

I'm not trying to be mean here, it's just that there are so MANY factors that enter into acoustics that it's really difficult to answer questions without first asking a few hundred of them myself... Steve

fbars · Post by **fbars** » Thu Apr 01, 2004 5:13 pm

Steve, thanks for the reply. I fully understand any questions you might need to ask before answering!

Sorry, but I am unable to post a drawing at this time. As far as items taller than 36", the 4 racks together, side by side are approx 5 and a 1/2 feet wide, and are 5 foot 8 inches tall. Similar to the racks that can be seen in the picture of Ocean Way Hollywood's Studio D. Each rack is 36 spaces. The console is approx 6 feet wide, with the top of the meter bridge about 40" from the floor. The racks will be directly across from the sliding glass doors. Hope some of that helps!!

I'll have to do some further research, I'm not sure what you mean by a "gradual impedence trap". I figure with the room my dimensions I'll have problems at 70Hz, 141Hz, 236Hz, 282Hz(?) and at 375Hz.

Thanks again for your precious time, GREAT forum!

Tom

knightfly · Post by **knightfly** » Fri Apr 02, 2004 4:04 pm

Juxtaposition is all-important in acoustics, and I'm not seeing your room in my head as far as console, speakers, your head, racks, sliders, front wall, etc - if there's ANY way you can find to post even a crude scanned in drawing...

The "gradual Impedance" thing is my paraphrase of Philip Newell's comments in his book - in it, on page 171, he diagrams a rear trap wall that's over two feet deep (and quite involved) that, from the attending text sounds like it would be close to a "black hole" for any frequency you'd care about. One of hundreds of details I'm "stockpiling" while designing my new facility. Your comment about using a couple of feet at the rear is what brought up my comment on that wall.

With the racks and sliders both slightly behind you, you have less of a problem than if it were the other way around -

As far as modes, your dimensions actually look pretty good - Bonello distribution curve shows no glaring problems, other than a slight "hole" at around 40 hZ. If you can do the "super wall" thing at the rear (I definitely recommend buying the book, and not just for that), then do the front part of the side walls with false splayed walls and put a cloud over your mix position, you should have a pretty usable space... Steve

fbars · Post by **fbars** » Sat Apr 03, 2004 12:33 pm

Steve,

I have ordered the book. Thanks for turning me on to it! I'll check out page 171, before making any final acoustical treatment decisions!!

Tom
First Bass Audio

fbars · Post by **fbars** » Sat Apr 10, 2004 11:41 pm

Steve,

I've read through the book, especially Chapter 11! I believe the rear wall absorber system, detailed in the 11.5 diagram, is exactly what I need. It's not to hard to built and I have plenty of space to do it.

I let you know how it works out!! At the moment, I'm still hanging drywall (only on the first layer) and as you know, there's never enough hours in the day.

Any idea where I can get a couple of months of 28 hour days??
Thanks for turning me on to the book and the idea!!

Tom
First Bass Audio

knightfly · Post by **knightfly** » Sun Apr 11, 2004 1:45 am

Tom, glad to help - BTW, if you aren't sure what Newell calls "dead sheet", as near as I can tell he's referring to loaded vinyl (such as Auralex Sheet Blok) - that stuff is expensive, but I've not found anything less expensive that sounds like it could replace it. Closest thing so far (absolutely NO research to back this up yet) would be cushion vinyl floor covering, but I doubt it would be "limp" enough to work the same. Even the thick vinyl Shower Floor Pan vinyl carried by Home Depot, etc, runs about $5 per lineal foot for 4 foot wide stuff, and it's not as thick as the Auralex stuff.

Been looking for that length days (and the energy to use them without all that time-wasting sleep crap) for quite a while now... Steve

Eric_Desart · Post by **Eric_Desart** » Wed Apr 14, 2004 3:48 am

Steve,

Standard roofing can replace it at normal indoors temperatures (careful with fire properties).
In the industry more bitumen like foils are used than vynil.
There are mass loaded bitumen type materials. They are much cheaper than vynil.

The fire properties of vynil are better, but the gas when it burns by an external source is at least or even more poisened (chloor).

This is valid if the vynil is PVC as I assume.

Eric

fbars · Post by **fbars** » Wed Apr 14, 2004 4:18 am

Eric,

Thanks for your post, here and elsewhere, on this and other forums!!
What do you mean "standard roofing"? Here in the US, standard roofing usually means, a "tar paper underlayment with asphalt/fiberglass type shingles". Are you thinking the "tar paper" is a possible substitute for the "deadsheet". It certainly is cheaper!!

Tom
First Bass Audio

Eric_Desart · Post by **Eric_Desart** » Wed Apr 14, 2004 5:23 am

Tom,

How do you call that: that black foil on rolls to burn on top of a roof?
The standard roofing as we call it, made from bitumen.
Please give me the correct English name, that I'm sure other people will understand this too.

I've a small technical English dictionary: it sais it's the same in English as in my language.

Bituminous materials have an internal damping which can even be better than the vynil foils.

For resonance absorbing purposes, such materials are also made in special versions with added minerals (the mass loaded thing) and sometimes with added weakeners to make the material more flexible at low temperatures.

Acoustically mass loaded vinyl is not better (even a bit the reverse) than bituminous foils.

The advantage of mass loaded vinyl is that it works better at very low temperatures, is a nicer material to work with, and has better fire properties.

Note that the acoustic effect of such visco elastic materials is very temperature dependent.

Note: the use of such materials is dependent on the application.
So I don't say a thing now about the fact if it sensible to use it or not.
My idea is that in the studio world people often have wrong expectations of this material

Regards
Eric