Drum iso room - Live application

I am taking my first shot at acoustic design and I am totally lost now. Problem: Live church performance, poorly designed room, VERY loud drummer. The audio guy wants the room at 100 dB. Drums are way over that, monitors have to overpower the drums and end up overpowering the mains. I need to isolate the drums from the rest of the room while maintaining a friendly acoustical environment. My budget is around $1500 and I may be able to get the lumber free/discounted. My plan at the moment which I pulled directly from my butt is to build 4 wooden walls all at 13 degrees off parallel. The room will be something like 6x8x7 feet (LxWxH) on a 1 foot riser. All of this is on top of a hollow wooden stage. For containment I am putting a 4'' gap in the wall which will be made of 2x4's and MDF, then fill that with insulation. Walls will be set at 13 degrees off parallel. Windows are made of 1/4'' plexi glass. For acoustics inside we had the idea to cut 8-12'' PVC pipe in half and make barrel diffusers then use some absorbers we have laying around. I read that drums don't like a dead room so I'm trying to diffuse before I absorb. Basically none of this needs to be perfect. The acoustics in the church are so bad that making the acoustics inside the drum cage totally perfect is going to be pointless. If the drums, mics and acoustics inside the iso room are at a 7 out of 10 I think that will be more than sufficient. The isolation also does not have to be totally perfect since we are just trying to get it to a volume that is significantly lower than 100 dB at a distance of 10-20 feet. Specific questions: Do I need to be super concerned with sealing the room? I need a door, some kind of ventillation. Isolation from the stage - Any cheap way to achieve this? The stage is REALLY boomy. Acoustical insulation/calk/wood vs standard. Worth all the money for my application? Diffusers made of PVC: Totally hair brained? Any specific diameters/lenghts/spacing? I'm not afraid of math if anyone knows some formulas that will help me target specific frequencies. Thank you for reading, my church thanks you too! -Matt Bailey -Midlothian, TX

Matt, I may not be a lot of help, but here is my thoughts. Hollow riser: Bad idea- it will INCREASE the boom factor. Fill it with mineral wool or something to keep it from resonating. Diffusers: a great idea in general but with that small a room I think it wont help. Better to fully absorb and close mic the kit, the rest of the folks on stage will love you. I know your situation is EXACTLY why a lot of churches use the electric drums, but as a drummer who has played those kits... I'd MUCH rather play an acoustic kit. I have a small 5 by 6 totally dead vocal booth that I have crammed my kit into many times and recorded with very good results, I dont think you will be sorry making the booth more absorptive. Good to see a neighbor! Good luck. Tom

Have you looked into a plexiglass barrier. They use them to control bleed over on stages all the time.

We are currently using a plexi glass drum shield and it does not seem to be helping much. The sound the congregation hears is just fine but the stage noise is insane. Thanks for the input! -Matt

Have you seen the plexiglass (well not sure of actual material) that Garth Brooks drummer plays in. Check out photo section in http://www.planetgarth.com/ I don't think you could do this and make it "look good" for $1,500. BUT IMHO, The band director OR boss man needs to ask the drummer to play softer... OR the drummer/church needs to switch to electric drums. This would be more cost effective and have a much better appearance then creating a drum room. Drummer is not the star of the show whether it's church or a rock show gig. At live gigs we need to be team players, with exception to some lead singers just because. I realize electric drum kits or playing soft (or just mixing in) may not be the personal choice of some drummers. After 20 years of doing mostly live gigs (for a living, 90% of the time band leader). Those: who play to loud, can not follow direction, do not come close to my requests and who can not play nicely with others.. I do not call back for the next gig. Again this is only my opinion. Marc

Matt Bailey wrote:

Basically none of this needs to be perfect. The acoustics in the church are so bad that making the acoustics inside the drum cage totally perfect is going to be pointless. Isolation from the stage - Any cheap way to achieve this? The stage is REALLY boomy.

any thoughts to trying to correct the overall church acoustics as well? I'd think that trying to get the stage boomyness under control would go a long ways... deadening material stuffed under the stage joists may help. from a riser standpoint, creating a riser and filling it with sand would give you increased mass but the stage might not be able to handle the extra weight. creating the booth will help but flanking sounds (boomy stage, etc...) will hurt the effort. electronic drums are the way to go... the FOH mix will improve greatly since the levels will be much easier to handle. maybe along with drum controls there is a way to add some diffusion/absorbtion to the church overall to help with getting a better acoustic environment? do it incrementally. some absorbers hung in the right places may help substantially.