Is triple leaf sometimes inevitable?

I just want to thank John Sayers for having this forum running for so many years. I built my first studio when I am 16 and this forum has helped me a lot. I am going to rent an empty loft soon and I only want to build a simple room in a room (I just need a square room, very simple to build and design, etc). I was wondering if the best strategy is to build a single frame with only Sheetrock on one side or do I need double frames with Sheetrock on both sides? Considering that the loft already has walls, my only concern is not to disturb the neighbors. Would building a double frame create a triple leaf system? Is this what we want in this case or not? Thanks

By the sound of it, (and some of the more seasoned people here hopefully can correct any mistakes I make) you will have a triple leaf with what you are building. If you move from the inside of your booth out, the first leaf will be the drywall that you put on your framing. You then would move, of course, through the airspace between your studs, until you hit the current wall of the loft. That wall would be your second leaf. Then you would move through the airspace of the existing stud wall, until you reach the wall of your neighbors' rooms. That would be the third leaf.

I now see that a third leaf is quite inevitable. On a long term project, I want to have at least to isolated square roooms in there. That mean that each of these rooms will have only one leaf of double gypsum (to create a MSM between those 2 rooms). The only problem is that it creates a triple leaf system with the exterior. The thing is that triple leaf in this case should be ok since there is no other options... am I right? Also, I have to check but the walls may be a single leaf (concrete) which may help.... I have read all the threads about triple leaf and there is a lot of confusing info, but I believe that I read somewhere that a triple leaf system can be effective if the resonant frequency is very low (for example, hotels use 4 leafs between rooms sometimes but the resonant frequency is very low so it does not affect the TL badly).

A hotel or mostly any hallway in a commercial structure is 4 feet wide. The mass/spring/mass of the wall on the one side of the hall and then the 4 feet wide "air" (the actual hallway) and the mass/spring/mass of the opposite wall is the four leaf you are talking about. In a residential building the hallway will be closer to 36 inches, but can be wider as well. Hopefully you will find that you have a solid concrete or block partition that makes up the boundaries of your place. In order to get the frequency down low that air gap in your space should be wide...wide like 36 inches if at all possible. But that doesn't begin to address some of the other issues you are up against. One is you mentioned this space being a "loft" which means it is built on a higher floor level. Flanking could be a bigger issue if you and your neighbors floor are the same, with no breaks in the floor to decouple it from the neighbor side.

I'm interested in this topic as well. I plan on adding on an additional room to my 9' x 24' storage room that's connected to my garage. I need to have a closet in the new room but that would make a 4 leaf system with the closet wall and the exterior wall. How can I build a closet without making a 4 leaf system? Sorry for the highjack, but hopefully some good ideas can come out of it.

Hello xSpace, I have been following many threads and your name comes back often and your post are very instructive and detailed, thanks for sharing. I read a bit on flanking and noise that gets transferred through the structure of the actual building and this is where I am stuck now. I know floating a floor is way out of my budget, but I read on the greenglue website that some heavy rubber and carpet can help. Would it be enough so that if I would build an other room in the loft, and both would be playing drums, they would not be able to hear each other? I know my posts are vague without any calculations for now, but I am only trying to understand the basic concepts here for now. Thanks

I am going to rent an empty loft soon and I only want to build a simple room in a room (I just need a square room,

That was the phrase that caught my eye: "A square room"... That would be a bad idea. It can be rectangular, but square isn't good. About the only thing worse than a square room is a cube room (where the ceiling height is the same as the width and depth of the room). So try to make it non-square. - Stuart -

Soundman2020 wrote:

I am going to rent an empty loft soon and I only want to build a simple room in a room (I just need a square room,

That was the phrase that caught my eye: "A square room".

Mine too. Sometimes it's the language barrier...sometimes it's just the use of the incorrect word. So sometimes...I bring it up and sometimes I do not :) Totally square, Brien

tenkas wrote:

Hello xSpace, I have been following many threads and your name comes back often and your post are very instructive and detailed, thanks for sharing.

+1 Andre

Sorry for the square... I meant rectangular (going to use a good room ratio so I can get a predictable result and then add treatment inside) this is going to be less complicated to build also. Here is something I was thinking about: let's say you have an empty loft. You then build a rectangular room with 4 walls and a ceiling (only 1 layer of double gypsum). Then you build 2 feet away an other identical room (4 walls + ceilings). If I understand correctly, I have created a MSM between the two rooms and this is the best solution possible for isolation (only between those two rooms). Considering that the walls are going to be mounted directly onto the concrete, will flanking be an issue if a drum is used in the room? If a drummer plays in room A and I am in room B, will I hear the drum softly or really loud? I can see that the only "easy route" for the sound would be to travel in the floor, but would using a drum riser or something equivalent be a good solution? Thanks to you guys, I can assimilate what I read in Rod's and Everest's book and things are shaping up in my mind.

If I understand correctly, I have created a MSM between the two rooms and this is the best solution possible for isolation (only between those two rooms).

Correct, provided that the leaves of the two rooms AND ALSO the outer leaf that encloses both of them are built properly, will plenty of mass, and are sealed airtight.

Considering that the walls are going to be mounted directly onto the concrete, will flanking be an issue if a drum is used in the room?

Possibly. It depends on the concrete: Mass, density, damping, etc.

but would using a drum riser or something equivalent be a good solution?

It could help, yes... provided that you build it massive and take care to not make it into a resonant box! - Stuart -

Thanks Soundman, very good advices. When you are talking about Concrete "damping", what are you referring too? Also, would building a drum riser (2 sheets of MDF on top of 3 inch of 3psf rockwool) be a good way of eliminating the resonance of a drum platform? Thanks

"Damping" refers to something that kills resonance in a resonant system (reduces the vibrations, or more accurately, absorbs some of the energy). A car shock abnsorber is one example. Another example: try to play a piano with a towel sitting loosely across all the strings, touching them: you can't play like that, since the strings are "damped" by the towel, and they won't vibrate. If your concrete slab is resting completely resting on the ground ("slab on grade"), then the earth underneath it is the "damping": the earth absorbs vibration energy, preventing the slab from resonating (or at least, greatly reducing resonance). But if your slab is only supported at the edges with nothing but air underneath (like it would be for the second floor of your house), then it is not damped well, and will resonate freely. That's the concept of damping. - Stuart -

Considering that there is no earth under the concrete, this means that it will resonate. In my country, this product is popular on walls and there is this new product for floors. Would this work in damping the floor? [url] http://www.materiauxspecl.com/en/pdf/so ... arning.pdf[/url] What are other known methods for damping a concrete floor that as a room bellow? Thanks

Found out about Kinetics today also. http://www.kineticsnoise.com/arch/sr.aspx Would this be a comparable product to the SonopanX or is it in a different category? Is it better? Considering there is only 1 concrete slab that separate me from my neighbors down, would it be effective on just lay some plywood on these kinds of mat? Would these mat eliminate resonance (type of resonance Rod talks about in his book about floating wood floors) Thanks

With what you have written, a floating floor is not necessary. Andre

Andre, This means that a single slab is enough to soundproof my drums from going to the level below me? Here is a simple drawing of what I want to do.

Can a hired professional calculate if there will be too much flanking or do I have to do my build, and then calculate?

tenkas wrote:

Can a hired professional calculate if there will be too much flanking or do I have to do my build, and then calculate?

I looked over the thread and did not see how much isolation you need. Isolation is expensive. Building more thatn required is a waste of money. Andre

I need to be able to play drums 24 hours a day. Neighbors are industries (a pretty loud place where they make jeans). I do not need extreme sound proofing but I need to be able to play drums without disturbing people working in an environment that already generates 90dB (for the workers). Also, no one is allowed to live in the building, so all my neighbors are gone after 6h00pm usually.

tenkas wrote:

I need to be able to play drums 24 hours a day. Neighbors are industries (a pretty loud place where they make jeans). I do not need extreme sound proofing but I need to be able to play drums without disturbing people working in an environment that already generates 90dB (for the workers). Also, no one is allowed to live in the building, so all my neighbors are gone after 6h00pm usually.

Making it explicit, you do not have neighbours that would be bothered by your sound. Your neighbours' sounds are not impact type against the floor or industrial type presses. If that is true, then you do not need a floating floor. Andre

I do not need extreme sound proofing but I need to be able to play drums without disturbing people working in an environment that already generates 90dB

continuous 90db????? At what frequency? I'd submit it is THEY who should be isolated from YOU! :mrgreen:

I believe that there is no heavy impact going to the floor from the factory (only people working on sewing machines). In case a floating floor would be needed, how much isolation does a floated wood floor directly on 703 offers? ( I remember Rod suggesting this..)

how much isolation does a floated wood floor directly on 703 offers

A lot. a little. A huge amount. And nothing at all. That's about the best answer that anyone can give to such a question that has no parameters! In any event, it seems that you don't need a floating floor, so why do you still want one? But seeing that you do want answers about how to float a floor, here is a thread that should give you plenty of answers: viewtopic.php?f=2&t=8173 - Stuart -

Thanks for the info. I will not float considering it is too complicated. Thanks everyone for the info.