Drum riser on casters: Solid bottom or not?

Hi everybody! (in my best Dr. Nick voice) Hey, great site! Thanks to John and everyone else who makes it possible. I've been lurking around and digging through posts for a few weeks trying to learn as much as I could, but I couldn't quite do the project without asking a couple (maybe dumb) questions. Okay, me: I have a basement recording/practice space in a duplex. I play Bass and Trumpet and am trying to learn a bit about Drums. My room is about 13' wide, 21' long, and 7' high. Actually the room is more like 40' long, I just don't usually use the other end for recording/playing, but the air volume is there. Solid concrete floor with nothing beneath me. Present sound and isolation are okay for me. Neighbor in duplex is cool with what I'm doing, and you can't hear band playing outside house when you get about 15' away, so I'm okay with other neighbors and noise ordinances. So this isn't about trying to improve sound or isolation, I just don't want to ruin the decent sound I'm already getting. Okay, project: I'm in the process of building a drum riser on lockable casters. I'm not trying to decouple the drums from the structure, I just needed them off the floor because I get a little water in the basement once in a while. It's on wheels because there's one spot that's really kind of the recording "sweet spot" where stuff sounds best, and I want to be able to just slide the drums over to another area when I record, say, just a single acoustic guitar. The riser is mostly built. It's 5.5' wide and 7.5' long. The frame is made of 2"x6" lumber screwed together with joist hangers. Joist cavities are to be "overstuffed" with standard pink fiberglass insulation. Was planning on screwing down a single layer of 3/4" plywood for top. Small rug will be stapled or scewed to top to help keep drums from moving around. Keep in mind that I don't want to permanently glue any of it together since I would like to buy a house in a few years and want to be able to dismantle this and take it with me. Tight stairway/wimpy body means the only way to get riser out of here later is to be able to dimantle it. Okay, Questions: I was going to have a solid layer of 1/4" OSB on the bottom to hold the insulation in place. Distance from floor to bottom of riser is 3 1/2". Is this okay? I don't want the riser to start giving off funny sounds when the kick drum is slammed. Or, do I need to have a layer on the bottom that's the same thickness (3/4") as the layer on top? Or, is closing off the bottom a mistake? Do I need to leave it more open, like have thin wood slats to hold insulation in place? Would prefer to close off with solid material (I already have 1/4" OSB lying around), but I've read conflicting posts concerning this. Like I said, I'm not worried about the solid bottom coupling me more to the concrete floor, I just don't want funny noises from the riser itself. Can I get away with a single 3/4" plywood layer screwed to the tops of the joists? Could afford to buy a second layer if I need to, but money's tight and I'd prefer not to. If I have to have a second layer, could it be (1/2") to save a little money? Do I need a layer of asphalt paper, or is that just to put between a double layer top? Oaky, that's about it. I appreciate any advice that anyone can give. If you need more info, let me know. Thanks.

Welcome! I know this isn't what you're asking, but personally, I would address the water issue and not simply adapt to it in this way. You say you "get a little water in the basement once in a while." Do you know where the water is coming from? --Keith :mrgreen:

Listen to Keith.... In my opinion, almost all basements should make provision for the possibility of water... It only takes that once in a while to ruin things and water can not only come from outside but also from the washer, hot water heater, and simply water piping.... Thought I was pretty much all set for the project (to be combined with extra water prevention preparations as I proceeded) but now I feel I should drop everything (except the outer-leaf ceiling) and concentrate on a fail-safe water system.... This was because of THIS year only, starting in May with the extraordinary flooding in our area, and then this past week with a 4 hour power failure DURING a torrential rain/lightning/thunder storm, which sent me scrambling to avert a catastrophe... Actually, I feel lucky -- not just since I haven't suffered damage -- but also since these events in my area 'woke me up' in time; these happened before I built the studio, and so alerts me to carefully choose materials/systems that address the possibility of water.... K

sharward wrote:

Welcome! I know this isn't what you're asking, but personally, I would address the water issue and not simply adapt to it in this way. You say you "get a little water in the basement once in a while." Do you know where the water is coming from? --Keith :mrgreen:

Once you figure out about the water (which I agree would be total folly NOT to do first) you need to NOT cover the bottom fully; better to try and find some pallet strapping and "contain" the insulation in that way. There should be at least one link for this here http://www.johnlsayers.com/phpBB2/viewt ... ping#46306 Perhaps a more solid way of "mobilizing" your riser would be something like this http://www.woodcraft.com/family.aspx?FamilyID=3703 These are made to support the weight of a table saw, so should handle your riser and drums OK. The advantage is that you're not relying on cheesy little brakes to keep things from moving around, the wheels get RETRACTED instead. This would let you put several rubber feet across the bottom of your frame for the riser to sit on during use, which would also improve stability... Steve

Wow, thanks for the fast replies, Keith, K, and Steve. Okay, I appreciate what you guys are saying about the water, but you're just going to have to trust me that adapting to it in this way is really the only option available as far as I can see. I do indeed know where the water comes from. It's through the foundation, and only when several factors line up. And I really do mean a little bit of water (1-2 gallons max) and once in a while (maybe 1-2 times in a year-I can go a year or two without any water). It's just that when water does show up, it likes to go right where I like my bass drum to sit. This is rental property. I don't have the funds to correct the problem completely, and the landlord won't be doing this either. We (me and landlord- he really is a good friend and very responsive to problems, but he's got a budget too) have already done a few things to try to take care of the problem. We've put extensions on downspouts to channel water further away from house, some landscaping to keep it away, etc. I think the only complete solution would be excavating in front of the house down to the bottom of the foundation and redoing a couple of the concrete blocks. I've been here for 11 years and I know this place really well. Some years I don't get any water at all. And water from other problems like washer, etc. is on other end of room and right next to drain. In addition, I don't have that much equipment down there. It's just the "loud noise area". My control room, console, computer, etc. is upstairs in living room. Anything in basement (guitar amps, P.A., etc.) is all on pallets and shelves. Everything is high enough that unless I got over 6" standing water, meaning that the drains have failed entirely, I'm okay (anything over 1/2 inch should flow into the drains). I'm willing to take the chance that the drains will be fine (I have a guy come out and check 'em and snake 'em every couple years). I'm also in a high point in the city and we just don't get real floods here. And if it got so bad that the drains did back up, well, there's really nothing you can do at that point. So, let's not worry about the water part. I think I've really done all I can. The riser is really more about precaution and convenience of being able to just move the whole kit with microphones away and back in a second without having to teardown and reset all the time. Steve, thanks for the caster idea. If mine don't work out, I'll try those (can't return the ones I already bought). Steve, thanks for the strapping suggestion, too. I'll do it, but I'm just wondering why I want to leave the bottom open? I remember one guy (think his tag was Giles117) said he really liked the sound of a sealed drum riser. I'm not trying to be difficult, I just always like to know the reasoning behind the process. Along those lines, could I use steel window screen to contain the bottom of the insulation? I've got a big roll of that just sitting around. Or could I go with wood slats or pegboard? Got very cheap access to those too. Thanks again, guys.

Also, since no one said anything about 1 layer of 3/4" plywood on top, does that mean that I can use just a single layer of 3/4" plywood? I noticed a lot of threads recommending 2 layers on floors and risers. Thanks again.

On drum risers, like floated floors, the thinner you make the top the more it will resonate. The less insulation you put in side, the more it will resonate. If you put a bottom on it, then the top, bottom, and your floor will create a 3-leaf construct which will wipe out any isolation value you may have gained by floating the riser in the first place. The bottom will also raise your resonant frequency, making it even MORE apparent in recordings. Maybe Giles liked the sound of a sealed riser because he likes boomy drums; I bet it would give somewhat of a "coliseum" sound to a kick drum, but what if you don't WANT that sound? :? Steve

Steve, Just a thought: If a riser is meant to 1) sit heigher, 2) decouple the drums from the ground. 3) Not to insulate airborn sound. I think a good manner should be to use top plates with holes or a perforated plate. I see this can also be unpractical (dust, holes for supports stands and chair). But isn't there a solution, one could figure out to solve or minimize this problem? Advantages: 1) Depending on the % holes one lowers MSM (or even prevent it to act as a panel on a spring) 2) A perforated panel can never sound as a drumskin (natural anti-noise). Question: what does do the Helmholtz effect? Note that industrial, the use of perforated panels to screen off dangerous things on machinery (e.g. belts) is a known practice in order to prevent such panels to radiate sound in themselves, normally caused by vibration picked up from the machinery by fixed mounting. Just a thought. Eric

Thanks Eric and Steve. Eric, I think I'll just stick to a solid top. It'll just be easier and more practical for me. Dust through holes, setting up drums and hardware on holes, etc. could be a problem and I don't want to build some kind of a resonator panel without understanding how it would affect the sound. Plus, I'd have to drill all those holes by hand. Thanks for the idea, though. Steve, okay, I'll definitely leave the bottom open. I'm not so concerned about isolation, but I definitely don't want to raise the resonant frequency. I already get a good recorded sound and I don't want to screw that up. Plus, I guess a little more isolation certainly wouldn't hurt me any, either. I'll try the single layer of 3/4" plywood on top at first. If it resonates too much, then I'll go ahead and put down the double layer of asphalt paper and put another layer of plywood on. I'll use a layer of canvas on the bottom to hold the insulation in place and I'll put 1x2's along (not across) the bottom of the joists to hold the canvas in place. I did look at that strapping material, but it was over $50 per roll, where as the canvas is sitting in my basement. Plus, I think the canvas would contain the glass fibers a little better. Okay, will the canvas be okay for containing the insulation? Could I use a really thin layer of plastic sheeting and then put the canvas over that to help contain the glass fibers? Or is that gonna screw things up? Okay, let me know what you think. Once I get your thoughts, maybe I can finish this up in a couple more days. Thanks again.

Coyote wrote:

I'll try the single layer of 3/4" plywood on top at first. If it resonates too much, then I'll go ahead and put down the double layer of asphalt paper and put another layer of plywood on.

Or, maybe if you can get ahold of a single tube of Green Glue (leftover from another person's purchase, since they're only available in full cases), then perhaps you can use that between your layers. --Keith :mrgreen:

read this thread http://www.recording.org/ftopict-36454.html

Thanks sharward and Ro. sharward: I think I'll have to stick with the asphalt paper in this particular case. I'm assuming the Green Glue is for permanent assemblies, correct? Well, I'm trying to make this riser in a way that I can completely dismantle it in a few years and take it with me when I finally purchase a house or get a better studio space. Thanks for the tip, though. I've read through several threads and the Green Glue sounds like really good stuff. I'd definitely try it if this were a permanent assembly. Ro: I did read that thread, and I'm really starting to think I might need to go with a double layer top. Okay, just to restate where I'm at right now and what my current questions are:

I'll use a layer of canvas on the bottom to hold the insulation in place and I'll put 1x2's along (not across) the bottom of the joists to hold the canvas in place. I did look at that strapping material, but it was over $50 per roll, where as the canvas is sitting in my basement. Plus, I think the canvas would contain the glass fibers a little better. Okay, will the canvas be okay for containing the insulation? Could I use a really thin layer of plastic sheeting and then put the canvas over that to help contain the glass fibers? Or is that gonna screw things up? Okay, let me know what you think. Once I get your thoughts, maybe I can finish this up in a couple more days. Thanks again.

Un-perforated canvas may degrade the sound, or it may not; it is, however, a "leaf" as defined by its gasflow resistance. You're right in that it will better contain any insulation fibers. Since it's free, and since you're building this as a "portable", I"d say go for it; if it doesn't work as well as you 'd like, you can always buy the strapping and redo the bottom... Steve

Thanks Steve, Yeah, I think I'll just try it like this. What I've got is a fairly thin painter's drop cloth type canvas. I think it'll be "breathable" enough but yeah, if not, I can easily redo it later. And hey, I might try those retractable casters after all. Part of my worry was I thought they might rattle as the drums were hit and I didn't want to buy some $40 specialty part that would wind up maybe just sitting on my shelf. But the company has a great return policy: 30 days, even if you used the part, basically no questions asked. They said if I installed them and didn't like them for any reason, I could return them and I think they even cover the shipping back. Thanks again Steve for recommending that company. Service like that is pretty rare. And thanks again to everybody else for the help. I'm so glad I found this site.