Need Help Treating a Shoebox for Sound

[TWSmith]

Hello folks,

As a long time weekend warrior, I really appreciate being able to absorb some sound wisdom (pun intended), tips and tricks from all of you. Thanks much!

I have a gig coming this weekend in a 40'x56' room. The various acts (lots of African percussion w/voiceover, a four-piece jazz band, and a few vocalists with tracks on CD) are performing along the long wall. Here are some other notes:

• the ceiling is only nine feet
• there are a pair of 2'x3' columns 14' from the rear of the room, (20' from the left wall, 5' from the right)
• the room has a hardwood (bamboo) floor, sheetrock walls, and your standard drop-ceiling panels

I've done a few gigs here, but not this detailed. The percussion instruments (djembes, congas, cowbells, talking drums, etc.) destroy this room with mid-lows (especially 315, 400), and I'm sure you guys have an idea what all the flat, hard surfaces do to presence on vocals.

I'll probably have two 12" tops on sticks, two 15" subs, and two 12" monitors. It's definitely more than I'll need for this room (i.e., for the jazz band, I'm thinking I'll only put vocals and keyboard in the house, minimal kick & overhead), but it gives me what I need to enhance rather than compete with the stage.

I'm just trying to get some ideas for quick, efficient sound-proofing for the gig. Let me know if you need any more information.

Any input is greatly appreciated!

 

[DaveySimps]

Any way to hang theatrical curtains, or some sort decorative piece like a tapestry? Or mabe pipe and drape?

~Dave

 

[Footer]

Pipe and drape would help a lot, velour would help even more. Get anything soft possible into that room. Even tablecloths on the tables will help. Also, when you get bodies into that room, if it is at all close to full, that will help more then anything.

 

[TOG]

I suppose acute appendicitis the day of the gig is too much to ask for?


I agree pipe and drape is a good start. If you have any kind of budget for dressing the stage I'd recommend rolled carpets standing on end in the corners and then artfully drape them with fabric and hang rag on the back/side walls.

Xylo and talking drum will be a hassle. Use small diaphragm condensers (like SM81's) on them if possible. For everything else I'd use large diaphragm condenser mics (KSM32's, AT4050's, etc) positioned like choir mics.

 

[TWSmith]

If I got acute appendicitis, I'm sure there would be some acupunture specialist or holistic herbologist that would find and cure me on the spot. C'est la vie...

At this point, pipe and drape will probably not be feasible (but will consider it as the long-term solution). Hanging black velour on the back walk (w/strongly anchored hooks) is a definite, especially since they have a cloth banner to go along the top which will help dress it up a bit.

The house should be packed, so the crowd will soak up a great deal of high frequencies. I'll drape the columns as well and position the speakers so that most of the dispersion field is on the audience.

TOG, thanks for the mic tips. I do like the choir mic approach -- the artists will have to go with the flow.

What do you (plural) think of side-fills/delay speakers? Instead of shaving the heads off the front row, I can get sound directly to the back of the room... just a thought.

 

[DaveySimps]

If you have the gear in stock, the delays are not a bad idea. I certainly do not think it is a must, but it might be nice to try it to see exactly what it can offer, especially if you have the gear and crew to do it.

Good Luck!
~Dave

 

[lieperjp]

What does the ceiling look like? I can remember some gyms and halls that I've been in that have sound tiling/paneling on the ceiling (Open steel roof, panels spanning the beams.) I know the likelihood of you putting actual acoustical panels on the ceiling is slim to none, but something that I've seen used before - quite effectively - is the foam insulation panels that go underneath aluminum siding on a house. If you can find them in the right color (and if you have the right type of ceiling) - I've seen them in pink, blue and white they might work. Of course, I may stand corrected.

Edit: I suggest this only as a temporary solution. I would not recommend this for a permanent installation. If you wish to do this, get proper acoustical panels and consult a professional to get the right kind that will work the best for your space. The professional will also help you make sure they are installed safely and correctly.

 

[avkid]

With all this talk of fabric and ceilings I feel obligated to point out something.

Make sure anything you permanently install is treated with a flame retardant and inspected regularly per the manufacturer's recommendations.

 

[museav]

If it is a standard acoustical tile ceiling, between that and a full house you will probably have sufficient of mid and high frequency absorption. And if it is standard sheetrock walls, those may actually provide quite a bit of absorption around 100-125Hz. What you may not have is acoustical absorption where it would be most effective.

I would avoid pipe and drape as a permanent solution. If you use it as a temporary solution you can also play with the spacing off the wall, that can vary the lower frequency absorption provided. Also consider that with the audience and ceiling, diffusion might be a better option on the walls than absorption.

I would be careful with delayed fills. This approach can work well if you run everything through the system but if you run only some sources through it you can end up with a different mix of the natural and reinforced sources throughout the space. Also, with what sounds like an almost square audience area (assuming some of the 56' depth is the stage), it is going to be difficult to get the coverage and delay times to work well with side fills, you'd almost have to look at overhead fills.

Finally, don't focus on just the audience, also consider the effect the acoustics have on the performers.

I think the idea of getting the sound at the audience and using speakers that have the proper pattern for the application is the best place to start no matter what else you do.

 

[TWSmith]

Museav, that's a good point about the effect of acoustics on the performers. They'll have two monitors, but parts of the show are interactive.

Thanks to everyone for your input and advice. I'm going to follow the K.I.S.S. approach: point the speakers more towards the audience, drape the wall behind the stage, and drape an eight foot wide space on each side. The dispersion of the horns in the mains is 90x65. Angled the right way, I'll get minimum splash off the sides and rear walls. Since they're on sticks, I'll have them higher than normal (maybe 1.5' from the ceiling). The crowd is expected to remain seated for most of the show.

 

[museav]

Typically, if you are going to drape walls you would drape the wall behind the audience to minimize the sound reflected off that wall and maybe not drape the wall behind the performers so they do get some sound between them. But play with it and see what works for the specific application.