Stage Curtains Draped Along Wall

[cw4u]

I've seen some theater spaces use a type of heavy stage curtain hung along the side and back walls of a building to (I'd assume) help with the acoustics of the space.

I was wondering if it would be possible to do the same thing for a building I work in. It's an exposed ceiling with drywall everywhere. The floor is carpeted.

I've got some curtains from a couple schools that are replacing theirs this summer, so I was thinking we could die them black and just have them hung where the drywall is.

How effective would this be?

Thanks!

[petereit]

I think it would be better to invest some time in a few good books and learn basic acoustic design principles (honestly, it doesn't take that long). Otherwise, you're just guessing and hoping and that rarely produces the desired effect.

The hours you invest in educating yourself now can literally save you YEARS of frustration in the future.

[Brad Weber]

Originally Posted by cw4u

I've seen some theater spaces use a type of heavy stage curtain hung along the side and back walls of a building to (I'd assume) help with the acoustics of the space.

Originally Posted by cw4u

How effective would this be?

I think that neatly sums it up, how did it "help" the acoustics of those spaces and how does that relate to being effective for you? You need to address what you are trying to do in order to assess how effective something is at doing it. This is a common problem with acoustics, many people (including some who claim to offer acoustical consulting and/or contracting) approach it as simply being a matter of adding 'soft stuff' and not as trying to address specific problems or achieve a desired result. In some cases simply doing whatever you can is beneficial, but does not mean it is effective at addressing every problem or even necessarily some of the more significant problems.

I would also find out why the schools are replacing their curtains. Factors such as flame spread and smoke ratings typically require such materials to be specially treated, a treatment that may have to be renewed periodically. If this is one of the factors involved in the curtains being replaced then that is something you would also want to consider.

[Esoteric]

Like they said, it all depends. You will be able to dampen high end frequencies easier than lower end sounds. But what is the problem? Too much kick? Snare too harsh? There really isn't a one size fits all answer.

As far as fire proofing, I can tell you there are a multitude of treatments. Personally I would buy pretreated fabric that was treated to last the lifetime of the fabric, rather than a temporary treatment. I know at the PAC the only reason we took the blacks down was to have them cleaned.

Boy that was a heck of a dry cleaning bill.

Mike

[cw4u]

Well, we're trying to reduce the "echo" in the room. It's not so bad during musical performances, but for speech, it's pretty noticeable. That is our biggest concern. I was hoping by adding a thick, soft surface in front of the drywall would help to eliminate some of that.

Btw, the curtains are just coming down because the school is buying new ones. However, one school is shutting down for good and is just being used for district storage.

Thanks.

[Esoteric]

Yeah, do a lot of research on soundproofing. I recently did for a client and learned a lot.

Mike

[Gracetech]

If the curtains are free there is no harm in trying it out. I would try it out before dying them though. Also if the curtains have been fire treated you will have to remove that treating before you dye them. Also you are going to have to do disperse dye to get the dye to take. I do not envy you for the ordeal you will have to go through to change the color of the curtains.

As for the curtains the effect of them on the walls is two fold. First they absorb quite a bit of sound and what they don't absorb they diffuse. The use of the curtains would be very effective at removing reflections but you may play with spacing the curtains out so as not to completely kill the room. Imagine rays of light coming out of your speakers and look at where those rays may hit first on the wall and consider that area your primary reflection and treat it first. If you still have issues then expand out from there.

BTW guys i don't think it's fair to tell someone to learn a subject that just wants some simple advice.

crt

[cmchamp]

Originally Posted by Gracetech

As for the curtains the effect of them on the walls is two fold. First they absorb quite a bit of sound and what they don't absorb they diffuse.

I don't want to start a heated discussion, however, I'm not sure this is an accurate statement.

1: curtains, or any other treatments, don't effect or affect the walls, they interact with the sound waves and add absorption to the room.

2: "quite a bit" can mean different things to different people. Chapter 9 of F. Alton Everest's Master Handbook of Acoustics addresses the use of drapery for absorption. Different weights of drapery have different densities and affect sound waves differently. Additional considerations are how thick they are hung. Maximum absorption happens when they are hung at 1/2 their length. Additional considerations are the depth of the air cavity between the drape and the wall as well as the thickness of the folds.

3: no reference to "diffusion" is made with regard to draperies in the Everest book, so a citation or reference is requested. Diffusion requires hard, reflective surfaces designed to break, or segment, sound waves.

[cmchamp]

Soundproofing refers to NTC (noise transmission coefficient) between room spaces requiring specific construction methods to achieve high NTC ratings. (also STC)

Acoustical treatments designed for absorption and diffusion do not "sound proof" a room.

[cw4u]

Thanks for the advice!

This will be a summer task for me so I'll be sure to let you know how it goes.

[Esoteric]

Once again I stand corrected by Cory. I bow to your superior acoustic knowledge (which is why I bring in an acoustical engineer for the heavy lifting when it comes to sound).

But that is what I was trying to say.

Mike

[cmchamp]

I by no means am trying to be a smarty pants, because there are still things I don't know. I was just clarifying for other readers.
As for the drapes providing diffusion, I'm still perplexed on that.
Drapes can be placed in front of barrel absorbers/diffusors on a rail to modify the acoustical environment of the room, but unless the drapes are vinyl backed (which would cause them to loose absorption properties, they are not a hard, rigid surface.
So, I'm still looking for answers to that.
C.