Drum platform/isolation

based on info from my thread: This was referenced for Drum kit isolation in another thread:

gullfo wrote:

build a drum riser with 3x 1" MDF on top of 2" 3PCF rigid insulation underneath. add clouds on the ceiling. if you need more complete drum isolation consider building a proper booth. http://img254.imageshack.us/img254/9493/drumriser2bp4.th.jpg http://img176.imageshack.us/img176/1316/drumriser1hm6.th.jpg

My problem is a live floor transmits the thump from foot movement and pedal sounds of my kit. I would like to more isolate the kit from the floor. The above design seems to have a significant flaw to me unless I am missing something in the design. The rim 2x6s will transfer the same vibration to the floor. Seems like the same design sans the edge frame would decouple a lot better. My own idea was to lay down a couple layers of carpet padding then float a couple layers of OSB on top and carpet on top of that. So a couple questions: -carpet pad idea.. good? bad? -Would the above design sans 2x6 frame work?... be better? -I have not started working with fiberglass acoustical insulation yet. Is the stuff strong enough to support multiple layers of MDF or OSB without the rim?

I think you would be better off building a complete frame so as not to put a load on the insulation. This would allow you to have airspace between the fiberglass and MDF. Also it would eliminate the possibility of compressing the insulation. I would then put the frame on these. http://www.auralex.com/sound_isolation_ ... _uboat.asp I would also put a layer of sheetblock between the frame and MDF layers as an additional measure to decouple from the existing floor. http://www.auralex.com/sound_isolation_ ... etblok.asp Carpet padding has very little acoustical value, therefore I don't think it would resolve your problem any. Also It isn't going to provide a stable surface for supporting the drummer. As a drummer, I hate playing on a platform that bounces all over the place. Hope this helps. Bryon

drthump70 wrote:

I think you would be better off building a complete frame so as not to put a load on the insulation. This would allow you to have airspace between the fiberglass and MDF. Also it would eliminate the possibility of compressing the insulation. I would then put the frame on these. http://www.auralex.com/sound_isolation_ ... _uboat.asp I would also put a layer of sheetblock between the frame and MDF layers as an additional measure to decouple from the existing floor. http://www.auralex.com/sound_isolation_ ... etblok.asp Carpet padding has very little acoustical value, therefore I don't think it would resolve your problem any. Also It isn't going to provide a stable surface for supporting the drummer. As a drummer, I hate playing on a platform that bounces all over the place. Hope this helps. Bryon

Thanks. The carpet padding would be under a platform, the drums would just be on carpet on top of the platform, but if the padding's acoustic isolation value is nil, I reckon it's back to the drawing board. I looked at U boats, I have a bunch of leftover EDPM from a roofing project I wonder if layering pieces up to 1/2" thickness would do the same job. Is there an advantage to MDF vs OSB?

mountainhick: You are missing something in the design, when the fiberglass is loaded, you have 1/2" clearance from the frame to the floor. The frame never touches the ground...think about it: 3" of MDF, 4" of fiberglass, and 22/32" of top layer. That is more than the 5.5" face of the "2x6". What kind of floor do you have now and what are your goals in trying to build drum riser? drthump70: I respectfully disagree with your advice. You DO want to put a load on the insulation. The "springiness" of the fiberglass is where you get your decoupling. You would not be able to put enough of a load on the U-boats to get any useful decoupling.

guitarman wrote:

mountainhick: You are missing something in the design, when the fiberglass is loaded, you have 1/2" clearance from the frame to the floor. The frame never touches the ground...think about it: 3" of MDF, 4" of fiberglass, and 22/32" of top layer. That is more than the 5.5" face of the "2x6". What kind of floor do you have now and what are your goals in trying to build drum riser? drthump70: I respectfully disagree with your advice. You DO want to put a load on the insulation. The "springiness" of the fiberglass is where you get your decoupling. You would not be able to put enough of a load on the U-boats to get any useful decoupling.

Indeed. I originally misinterpreted the drawing, and realized what it was about after finding a few other references to this kind of platform. Really the 2x6 edge is not even a functional part of the support for the thing, and based on other designs I have found the edge seems functionally superfluous. Anyway, I was chastised for starting this thread in addition to the original for my studio project, and will continue all aspects of my projects back on the original thread from here: viewtopic.php?f=1&t=11514

"I have found the edge seems functionally superfluous" It keeps the assembly together. Placing these materials on top of one another and then an active body with kinetic energy will cause the platform to drift apart.

xSpace wrote:

"I have found the edge seems functionally superfluous" It keeps the assembly together. Placing these materials on top of one another and then an active body with kinetic energy will cause the platform to drift apart.

OK, thanks