Is this drum riser idea a good one?

I'm going to try to minimize vibrations coming through the double wall and floor from the adjacent drum room. I got this idea off of those speaker stands with spikes on the bottom to decouple from the floor. My plan: Build an 8ft by 5 ft frame out of 2x4 and reinforce it with crpss braces about every 2 feet. Cover one side with plywood and fill the cavity underneith with rockwool or something similar. Cover that up of course. Then, I make 4 little short legs out of 2x4s that stick and hold the entire thing up off the floor about 2 inches, and each leg will be cut to a sharp point and resting on thick gum rubber pads or hockey pucks. I'd also use this platform for loud overdubs later. Sound like a good idea or no? If so, is 8x5 big enough? Thanks Paul

I hate to burst your bubble, but if I'm not mistaken, the points on the feet of speaker stands are to stabilize them when they are put on carpet. They serve no isolation purpose at all so putting pointy 2x4s for feet would probably not do anything. As to size, I have a reasonable drum kit in my studio drum room (HH, Snare, 2 toms, floor tom, kick drum and two cymbals on stands. My room is 12 x 11' and it's a tight fit once you get a drummer in there. I'm thinking that 8x5 would be way too small if you want to make sure the drummer doesn't fall off the riser. I think you might get better results if you build a bigger riser and fill it with dry sand instead of mineral wool but wiser minds my differ with me. len

I'll take that argument. The idea of the cones is that large vibrations (bass) are not passed onto the floor, coupling the floor to the speaker, and turning the floor into a big boom box. I've actually heard them called "decouplers" before. Bass takes up a certain amount of space, and wont fit through the point of a cone. Now, I'll admit I may be wrong too, but I've had the idea that the cones are for that reason, in my head, for at least 10 years and I wont let go without verification either way. :) I'd be willing to go as high as $5 on a bet though ha. Thats semi-confident at least. Someone that knows, chime in!

First thing I could find doing a quick search... Read the text under the picture. I'm not the first to have this idea in my head. http://www.polycrystal.com/Z-SPIKES.htm

Just found this too: "In an ideal speaker system, the only parts that would move are the driver diaphragms. Unfortunately, due to Newton's Law, every time the cone moves forward the equal and opposite reaction moves the driving magnet backwards and vice versa. This energy is then transmitted through the basket to the baffle, and hence the rest of the speaker. The air inside the cabinet also vibrates, passing further energy into the structure. If this energy is allowed to move the cabinet backwards and forwards then it will rob the speaker of information and energy, reducing definition and clarity." "Spiking speakers and speaker stands is a very predictable way of controlling the interface between the speaker and its environment. Speakers sat on carpets, with or without stands, will move about in an undefined manner. The resonant frequency of speaker wobble on carpet cannot be predicted as no two carpets are the same. Spikes pass through the carpet, sitting directly-on the floor. They can be adjusted to remove wobble, and the small surface area of the spike creates a huge psi, which in theory will improve the situation still further. The use of feet or spikes between a speaker cabinet and its stand (or the floor) also gives the bottom of the cabinet room to flex predictably, and then the speaker designer can take this into account."

I stand corrected! :-) Good thing I didn't take you up on the $5 bet! The idea of PSI loading (i.e., putting the weight on the smallest surface area) is interesting. I sounds reasonable. Are these things expensive? Is there a reason you couldn't use a few of these on your drum riser? Remember that speakers are pretty heavy devices (the good ones) so these are probably pretty strong. len

One thing that theory doesn't take into account - with something as large as a drum riser, you now have a fairly efficient "air pump" consisting of the upper surface (the diaphragm) and the point loaded suspension of spikes - this means that, without considerable damping (and hopefully high mass) of the top surface, you'll more likely INCREASE the amount of perceived bass in the room with such a riser. The point loading thing is OK, but I'd make the mass of the top as high as practical and either sand-fill or fill with mineral wool under 5-10% compression... Steve

Yeah I plan on stuffing the bottom full of Rockwool. Maybe I'll just buy 6 or so of those heavy spikes and mount them directly on it. There are some "audiophile" cones that get up into the $100 each range, brass ones, steel ones, gold ones, ceramic... I think any dense strong metal will do though. Peace Paul

Personally, unless you have a TON of money to waste I'd stay away from so-called "audiophile" sites, unless you need a matched set of these http://www.referenceaudiomods.com/Merch ... gory_Code= (no, they're NOT kidding :? ) Steve

len wrote:

My room is 12 x 11' and it's a tight fit once you get a drummer in there.

Sounds like len's room might be snug if you have to squeeze mic stands in there, too. But if the stands can be on and around, and not in a room, maybe the actual footprint of the riser can be smaller... maybe 8'x8'? Just a thought. Our drummer squeezes his 5-piece and himself onto a 6'x6' (with no room to spare!) Creatch

I thought the cones were to improve the bass, well at least remove any muddiness from the sound so you get more clarity. There was a similar idea punted about on here, but the whole riser floated on the rockwool, actually I think it was one of Steve's suggestions. The guy (German I think) built it and said that it did cut down on the amount of kick drum getting through to his neighbours.