Basement Drum Room

[drummerdude]

I am new to the forum, and am looking for some suggestions as to the best way to build my room, if I don't have enough information in this post, tell me what is needed, and I will gladly add it.

I live in a townhouse, middle unit. right now I only have 1 neighbor, but that could change next month.
The room will be in the unfinished basement. The basements of each unit are separated by a concrete wall of unkown thickness.
I bought a drum set and need to be able to play it without the neighbors being disturbed.
The height of the basement (to the bottom of the floor joists) is 7ft 4in. I have 8ft x 8ft to work with (can be changed if necessary, but 8x8 works best). the 8x8 will be 2 ft from one neighbor wall and 6ft from other neighbor wall
my budget is up to $1000 (for materials), but closer to $500 would make me very happy.
my current plan was to do a double wall with single type x (5/8) outside and inside, and I have not tackled air exchange yet.

I'd prefer if my neighbors couldn;t hear the drums at all, but can settle for a non-disturbing db level.

Thanks for the Help

[drummerdude]

I may be able to get into the vacant unit next door, and do some test to see what db level is at with no room, if that would help considerably.

[drummerdude]

I can;t gt over to the other unit yet, but I measured the two loudest (at the lowest freq.) drums, the bass drums and snare measure between 80hz and 200hz, on my main floor (open joists in the basement with no insulation) comes up at 50db for the snare and 60db for the bass drum. given the concrete separating the basement units, I think I can get away with one wall, double 5/8 on both sides with resilient channel on one side. Any input is appreciated.

[xSpace]

The issue is, drummerdude, is that you want to build but you do not want to get caught up on what it is you are doing.

I'll make a deal with ya. For every dollar I save you, make a donation here, since the pictures always push the data cost higher.

You are in a basement. The first thing you want to do is look up. This overhead floor area is your current path of least resistance, meaning it doesn't matter what you do to the walls and what you are attempting to do with your walls is wrong, but this overhead area has to be addressed first.

This area has to have mass added to at least attempt to get to the level of isolation provided by the, most likely, 5-1/2" thick concrete foundation wall of the basement. That cannot be done with simple sheetrock but the attempt has to be made with in reason. Typically two layers of 5/8 inch thick fire rated sheetrock with greenglue in between the layers is going to be a better fit.

Your walls...heck, lets address what you have picked up from google-acoustics-101 so far. The wall assembly you are attempting to build has all the right stuff, it has the four main components required to isolate sound.

It has mass (sheetrock) it is decoupled (via the RC) it has insulation(via the insulation) and it has air/distance(the thickness of the framing members plus the RC).

This is a typical mass/spring/mass assembly.

The problem is, and google-acoustics-101 has not gotten you this far, which is good, so you can say you heard it here first. This will be a typical 3 leaf in your current configuration.

A 3 leaf has the well known property of reducing low frequency isolation and this is undesirable especially with a room devoted to such low frequency generators as bass and/or drums.

So while you do have a wall assembly with mass on both sides of the framing that breaks the vibration path sound travels on using decoupling, the problem is that your existing basement wall should be considered the first part of the assembly, it is the first "mass" in your attempt to design a mass/spring/mass assembly.

[xSpace]

Sorry, one more thing.

The idea that you only have an 8 foot X 8 foot area has to be modified. The second worst possibly acoustic environment is a square, two sides being equal (8X8). The reason is that rooms have modes associated with the two walls laid parallel to each other. In a rectangular room you still have this effect, but it will be at two different frequencies. In a square room you will have this natural frequency associated with one pair of walls, and reinforced by the other set of walls at the same dimensions.

And to be clear, it does not have to be a wall, it can be any hard boundary like the floor and ceiling with the same dimension of a wall/wall.

The only thing worse to the human ear might be a cube which has three reinforcements.

[drummerdude]

I can do 8x7, height will be 7'4". what is the proper way for me to build the walls. I'd prefer the room to be free standing, as I will have to get a permit from my co-op to build onto the house. Thanks for the input, is there any free reading you can suggest to me to increase my knowledge on soundproofing? thanks again.

[AndreaBonilla]

Oh wow, I think you have an architect degree or something because that really looks amazing. This room totally rocks! I'll at least try to do something similar, thank you for the idea!

[SPAM SIGNATURE REMOVED BY MODERATOR]

[drummerdude]

I read up on the "leaf" effect. so would I be better to have 2 layers of drywall on the inside (on rc) and insulation, but no drywall on the outside?

[xSpace]

No sir. What you have is a massive exterior leaf in the existing concrete boundaries. then you would frame a wall and install sheetrock to the interior side of this newly framed assembly.

The newly framed assembly is already decoupled from the structure so the RC is a waste of money and does not help you and in fact will reduce your walls ability to isolate low frequency.

[drummerdude]

Thank You very much, when I build my room, I will set aside some money for a donation to the site. just to make sure I am correct, I should insulate and decouple some sheetrock from the ceiling, frame a non square room and insulate it and sheetrock the interior. any advice on how to do air exchange?

How much performance will I lose if there is no drywall on the basement ceiling, I know the performance might suffer, but how much? would putting sheetrock on both side of the ceiling of my new structure help that at all (outside walls would still have no sheetrock).

[drummerdude]

will it make a difference if the sheetrock is on the outside of the walls, vs the inside of the walls? Thanks

[xSpace]

When you have multiple air gaps enclosed with multiple mass layers, like a coupled floor assembly with plywood on the upper side and sheetrock on the bottom side, it would be better to simple install more mass to the underneath side of the ceiling.

Ideally, you would remove the existing sheetrock, mass up the top side and then either use RC to decouple the new sheetrock OR (BETTER) frame up on the top of your newly framed wall assemblies a decoupled ceiling that breaks that path.

You have to look at walls and ceilings like they are a "wall". If you can get a grip on what it is you are doing with a decoupled wall assembly, then it is easier to take this information and use it for the ceiling, since it is the same process only one is vertical and the other horizontal.

John Sayers is the Author of inside out walls, which is what you refer to when you say "will it make a difference if the sheetrock is on the outside of the walls, vs the inside of the walls?"

It makes no difference to sound vibration as to which place in time it encounters a barrier. What does matter, how ever is the air space. If the air cavity gets too cramped( is too small) then you run a the real risk of several things, one being that you need that air space to at least be 12 inches to reduce the potential for sound to enter and second you can actually create a coupling with a small airspace.

But if you have the room, like say a few feet to give up, then you could research the "inside out wall" that John uses...it would be a good thing to your build.

But we are talking about drums, and the more air the better, the more mass the better...

[drummerdude]

do you have a link where I can read about the inside out wall? Thanks

[BriHar]

http://johnlsayers.com/Recmanual/index.htm

[drummerdude]

http://johnlsayers.com/Recmanual/index.htm

I read through each tab and I couldn't find specific mention of an inside out wall.