Help! Acoustic Treatment for Troubled Space

[resound]

Howdy. First post. I work at a school where we just opened a media classroom in a rennovated warehouse. The room is a big shoebox, with one long wall of exposed brick and the other three drywall. The ceilings are very loft-like with exposed, cylindrical ductwork. I'll guess that the room is about 25'x50' and maybe 18' ceilings.

The acoustics, as you can imagine, are horrible. The room is far too live and there's constant whitenoise from the HVAC. I have trouble even managing to talk to students from ten feet away. The sound is just swallowed up and washed out. Playing audio is a joke.

I'm trying to get the school to address the situation. Right now there is zero budget so I'll have to fight for every incremental improvement. Plus, the room is shared with photography/visual types who are very attached to its swanky vibe (read: I cannot destory the aesthetics).

So, I guess I'm just looking for any recommendations. What's the first thing you would do? Wrap the ductwork with insulation; ceiling baffles; absorbtion along the walls? What product would you use? This is a situation where bang for the buck matters, and DIY will be near impossible to get approved for all sorts of silly reasons.

[Ethan Winer]

Vuk,

> Right now there is zero budget ... DIY will be near impossible to get approved <

Well that's a problem!

> Wrap the ductwork with insulation; ceiling baffles; absorbtion along the walls? <

Yes, all of that.

--Ethan

[resound]

Thanks for the response, Ethan. Would you have any specific recommendations for the ducts or for some sort of baffle?

I'm trying to work the angle that the studio art folk could make a project out of this: buy a bunch of 703 and let them wrap it, shape it, mount it in ways pleasing to them. Of course, they don't care about how the room sounds so I'll be fishing for a miracle here.

[Glenn Kuras]

I thought you could not DIY?

[Jules]

Post some photos? (dont get into any trouble over it though...)

[stevep]

VukOnCrack buy a bunch of 703

2" 703 .... that stuff is around $1 a square foot !
unless you buy a semi truck load.
Roxul mineral wool RXL40 is cheaper and works about the same.

For a low budget fix you could try to find (around your school) some cubical partitions they are usually made from 703 or equivalent. And put them against the walls...... Carpet on the floor will also help allot.

Hope you can get it worked out.

[matt thomas]

wrap the pipes in mass added vinyl, unless of course the HVAC has vents into your room in which case you're f#cked (sorry), get another room.

Local industrial insulation specialists should have a product especially for this purpose, it will make use of mass added vinyl..

like this stuff
http://www.sweetwater.com/store/detail/SheetBlok430/

narco

[resound]

Originally Posted by myfipie

I thought you could not DIY?

It's a very touchy area. The Uni. has all sorts of facilities policies, etc.. However, if I could get one of the studio art guys to want to create and hang some "work" in the space, that would be a different matter. It's not a DIY retrofit, it's art....

I'll try to get some pictures next week and post them (off campus until then).

Cannot get a different room. Lucky beyond lucky that we even have this. I know the room will never be good but making it remotely useable for teaching some basic audio stuff would be nice.

[matt thomas]

If you make removeable, not fixed traps etc the Uni won't mind because you're not touching anything that belongs tho them..

narco

[resound]

Here are the pictures I promised. You should be able to see how unfriednly the space is to sound. Any thoughts are much appreciated.

Thanks.

<a href="Image 1"><img height="240" alt="aw_b2f1.JPG" width="320" src="http://www.cs.duke.edu/~jeb12/aw/aw_b2f1.JPG"></a>
<a href="Image 2"><img height="320" alt="aw_b2f2.JPG" width="240" src="http://www.cs.duke.edu/~jeb12/aw/aw_b2f2.JPG"></a>
<a href="Image 3"><img height="320" alt="aw_f2b1.JPG" width="240" src="http://www.cs.duke.edu/~jeb12/aw/aw_f2b1.JPG"></a>

[Ethan Winer]

Vuk,

> Any thoughts are much appreciated. <

I don't see the pipes and ducts as your main problem. Just the large amount of bare, reflective surface. So all of my standard advice applies here too. Cover those surfaces with rigid fiberglass or equivalent.

--Ethan

[jajjguy]

Sounds like you have an HVAC noise problem and a room problem. And the room is amplifying the HVAC noise. It would really be best to deal with the HVAC noise first, but this may require a system-level solution (like placing silencers in the ductwork up near the big air handling units, lining the ductwork with sound absorbing material, and maybe more). But it sounds like that won't be an option for you. If you treat the room (according to all the standard prescriptions, like Ethan said), then at least it won't be amplifying the HVAC noise... but the noise will still be there.

Wrapping the ducts is not likely to help much, as the largest share of the noise is probably coming through the openings, which you'll need to leave open for air.

On the positive, the place does LOOK nice...

[aintnosunshine]

Originally Posted by stevep

2" 703 .... that stuff is around $1 a square foot !
unless you buy a semi truck load.
Roxul mineral wool RXL40 is cheaper and works about the same.

Tell me more about this mineral wool. What's the price point like in comparison to 703, and is the absorption the same for about the same amount of panel thickness? IE, 4" 703 panels.

[resound]

Thanks Ethan and jajjguy. You're probably quite right about the HVAC noise getting amplified. Everything is so diffuse in the room. I'll take my case up with the powers that be (again) and see what happens.

It's a fun facility and such a good step even though it's far from ideal for sound: sort of a jack of all trades master of none situation. And did I mention a freight railway passes within about 10 meters of the building?

If I have good news on this front I'll surely post it here. Thanks again.

[stevep]

http://www.roxul.com/sw34066.asp

Tell me more about this mineral wool. What's the price point like in comparison to 703, and is the absorption the same for about the same amount of panel thickness? IE, 4" 703 panels.

The RXL 40 Is real close to the 703 you should go with the 2"

[mixerguy]

703 works well

you can cover with fabric