Good layout? ..and dbl stud/dble leaf system question

Hi everyone.. I am about to build a basement studio and I have the whole general design laid out in sketchup. I am about to do more specific models of the individual rooms, but I wanted to see what you all thought of this configuration. The pictures of the proposed design as well as the basement empty are at the bottom. A bit about what I need: About 50-60 db of isolation between the control room, live room, and iso booths, and between all of those rooms and the rest of the house/outside. Not running separate duct lines from the furnace to the different rooms, but I am planning on using some acoustical duct liner for the main trunk lines and a vent that seals when closed for when I am tracking. I will be tracking drums in the tracking room, and I usually mix around 85 db. The one thing I'm confused about is how to construct a double studded/double leaf system when the other side of a room that needs isolation is not going to be finished. For instance, the wall where the entrance to the drum room is should be the double stud/double leaf system. But that other side of the drum room is the lounge, and I don't want to finish the lounge in a way where it's a "room within a room" type of construction. So how do I build the two leafs when one side doesn't enclose around another room? How do I seal that leaf on the side of the lounge? Also, when I put a ceiling on it, should I put the ceiling over the whole drum room and extend it over the outer leaf on the lounge side? I attempted it on my model for in between the drum room and lounge, but I didn't draw in a solution for in between the control room and lounge. So, same situation there. I tried to post a sketchup file, but its too big @ 5mb. Thanks so much for any help!

Anyone?? Need help please!

this should make your sketch up drawing smaller, then you can get it posted up here. will help people to help you and show you ideas. Click Window > Model Info. The Model Info dialog box will open. Click Statistics > Purge Unused at the bottom of the window. re save it and it should be smaller :-) try posting it again

as regard to the whole double leaf concept the attached should give you an idea. this is only ment as an illustration and is not a design. Basically with a little bit of planning you can stick your isolation where you require it. the section of stud wall that you put in to form the rest of your lounge area forms the first leaf of the other rooms that they back on to, creating a two leaf msm system. hope this helps.

Thanks Leon, Unfortunately, I purged the file and it didn't get much smaller, still too small @ 3.5 mb.

the section of stud wall that you put in to form the rest of your lounge area forms the first leaf of the other rooms that they back on to, creating a two leaf msm system

I have no problem putting a stud wall on the lounge side of the live room, and thus forming a two leaf/ double studded system for that side of the live room. However, totally finishing out the lounge area and hallway leading out of the control room next to the stairs and around to the lounge is not something I really wanted to do since I don't care if that section has a finished look or not and can save some money. But then the problem becomes how to seal off that 2nd leaf of the live room wall on the lounge side so that sound doesn't just go right through the floor joists above negating the wall. It seems like sealing off that wall all the way up to the floor board above and around the joists, and around this and that, etc, while ALSO having to coupling that wall to all of that stuff seems like a hard job to do. I'm just trying to figure out if there is a way to get dbl stud/dbl leaf isolation from the live room without having to finish those other areas off.

I have no problem putting a stud wall on the lounge side of the live room, and thus forming a two leaf/ double studded system for that side of the live room. However, totally finishing out the lounge area and hallway leading out of the control room next to the stairs and around to the lounge is not something I really wanted to do since I don't care if that section has a finished look or not and can save some money.

You seem to be missing the entire concept of how two-leaf room isolation works! You CANNOT just do one or two sides of the room. You MUST do the entire room. If you want good isolation for your room, you simply do not have the option of only doing some walls. As Leon correctly showed, you have to do all sides of the room the same, and also the ceiling. Think of it like an aquarium: if you want to build an aquarium, you MUST put glass in all sides. If you put glass in only one side, and tape cardboard across the other sides, obviously it won't hold water. Same with your room: Unless you build the complete two-leaf system all around, on all sides, then your room won't hold sound, just like the aquarium won't hold water. Let me put it another way: If you build one wall that theoretically isolates at 60 dB, but the other walls only isolate to 30 dB, well then the entire room is only isolated to 30 dB. Why? Because sound takes the easy path out! It will simply ignore your wonderful wall, and "flank" around it by going through the walls that you did not isolate. Game over. "Soundproofing" a room is "all or nothing". If you don't do it all, then you did nothing.

I don't care if that section has a finished look or not and can save some money.

The walls are not there for getting a "finished look": they are there as part of a tuned isolation system. If you leave one of the walls out, then you have no system, and no isolation. So it won't save you money at all: in fact, it will waste your money, since whatever you spend on doing one or two walls really well is pointless. Just as pointless as taking a cardboard box and putting a nice piece of glass in one side, thinking that you now have an aquarium... :)

But then the problem becomes how to seal off that 2nd leaf of the live room wall on the lounge side so that sound doesn't just go right through the floor joists above negating the wall.

Bingo! :) That is, indeed, the problem, isn't it?! Any wall that you DON'T build around your room will give you the same problem: Sound will take that path out, ignoring the walls that actually do isolate. (Or rather, "ignoring the walls that would isolate if the system were complete").

It seems like sealing off that wall all the way up to the floor board above and around the joists, and around this and that, etc, while ALSO having to coupling that wall to all of that stuff seems like a hard job to do.

More than "hard", the word you need there is "impossible". Because it isn't just about sealing: it is about building the complete 2-leaf system, which MUST be complete in order to work. Don't get me wrong; you still do need to fully seal the floor above! You can't skimp on that either, since isolation requires perfect air-tight seals. But that's not the issue I'm talking about here. IN ADDITION to fully sealing your existing outer leaf, on all sides, you ALSO need to build an inner leaf on all sides (and that inner leaf must also be sealed).

I'm just trying to figure out if there is a way to get dbl stud/dbl leaf isolation from the live room without having to finish those other areas off.

Then I'll save you the trouble of trying to figure it out: The answer is "no": it cannot be done without completing all sides of each room. There must be two leaves, and only two leaves, between one room and the next, in all directions. That's the basic concept. If there is only one leaf in a certain direction, then you don't have isolation. If there are MORE than two leaves in any direction, then you also have a big problem. There can only be two leaves, not more, not less. 2-leaf MSM isolation is based on the laws of physics. You can't get around those laws by wishful thinking, or by not wanting to spend the extra money. There are no magic solutions, unfortunately. The only solution that works is the one based on physics, which implies that the system must be complete, all around the room, in order to work. Take a look at what Leon drew for you: that's the correct and only way to do it. (Or rather, the only logical, sane way to do it at low cost and with common building materials. There are other ways to do it, also based on physics, and they will work too, but you'd better have a huge amount of money of you want to try those, as you'll need some rather expensive materials... ) Sorry to be the bearer of bad tidings, but that really is the harsh, ugly truth: if you want good isolation, you have to do all sides of your room to the same level, or don't bother doing anything at all. Only doing some sides is a huge waste of time, money and effort. - Stuart -

Stuart: I totally understand what you are saying about having to build the whole system in order for it to work to its full isolation potential everywhere in the entire proposed space. But I might be OK with not having a full 50-60 db of isolation between ALL of the different rooms in my design and the upstairs. So if I once again am making a mistake in my thinking, please AGAIN correct me! lol .. be patient, I'm new at this. :) Also, let me add this: I may only want to budget for 1 solid core door for the entrances to the live room, control room, and ISO booth So to save a lot of money, I may only need this: 50-60 db of isolation between the control room and live room 50-60 db of isolation between the iso booth and everything else. 50-60 db of isolation between the control room and upstairs 50-60 db of isolation between the live room and upstairs. BUT only 30 db total of isolation between the control room/live room and the lounge/wetbar area. only 30 db total of isolation between the lounge/wetbar area and upstairs. (which I have already due to standard construction of the house) So what I think I understand is that the dbl leaf/dbl stud system isn't going to stop any more of the sound from the control room or the live room from going upstairs over a standard two leaf wall (as long as it's decoupled) because in the dbl stud/dbl leaf system, what ever gets out of the inner leaf of the live room will flank upstairs through the gap in between the inner leaf and outer leaf anyway. AND, since I clearly have two leafs in between the control room and live room, control room and iso booth, and iso booth andlive room, adding the outer leaf to isolate the lounge/wet bar from the live room/control room area will add more isolation to the lounge/wetbar than necessary. Again, I don't care too much if the drums are not isolated by 50-60 DB to someone who is sitting in the lounge area. So if all of that is correct, and I want to save some money by not fully finishing the lounge/wet bar area and by only buying 1 solid core door for each entrance way, maybe building standard walls for the specific walls of the control room and live room that lead into the wetbar/lounge area respectively, and not installing a ceiling in the wetbar/lounge is all I need to achieve the amount of isolation I need?

So what I think I understand is that the dbl leaf/dbl stud system isn't going to stop any more of the sound from the control room or the live room from going upstairs over a standard two leaf wall (as long as it's decoupled) because in the dbl stud/dbl leaf system, what ever gets out of the inner leaf of the live room will flank upstairs through the gap in between the inner leaf and outer leaf anyway.

Weeeellllll, sort of, but not really! :) OK, it works like this: Each pair of facing leaves is a resonant system. Technically, it's a Mass-Spring-Mass system, where the two leaves are the two "masses", and the air between them is the spring. (Yes, for sound waves, air is VERY springy: we don't normally think of air as being a spring, but it is). So it's not that sound goes through one leaf, and is then in the air gap, where it can go somewhere else. Not at all. When sound hits the wall, it encounters the entire tuned system, and the tuning is what stops it. If you know anything about electronics, then this is like a simple RC tuned circuit: current doesn't just arrive at the resistor, flow through it, then encounter the capacitor. Rather, the current reacts to the PAIR of components together, as a system. Not two individual items, each doing its own things, but a team acting together; the whole is greater that the sum of its parts. The parts interact to do something together that is not possible if they act alone. The reason why you build walls like this as a two-leaf MSM system, (apart from "because it is the cheapest and simplest way to get high levels of isolation at low cost"), is because the wall acts just like the RC circuit: It is a low pass filter. It allows through some frequencies, at the very low end, but it blocks all higher frequencies. The system itself resists, and "fights back" when sound waves of higher frequencies arrive. Think of it like pushing a child on a swing in the playground: The swing has a natural frequency, and if you synchronize your pushing with that, then it's real easy. Just a tiny push at the right point in each cycle keeps things going: the swing system is "resonating" at its natural frequency. Now try to make the swing go twice as fast.... :) Get the picture? YOU CAN'T DO IT! The swing does not "want" to go at any other speed: it fights back. If you push it at the wrong moment in the cycle, your push is ineffective, and you have to work really hard to make it change its motion. If you really shove hard and fast, you might force it to go at twice it's natural frequency, but with great difficulty. Now try to make it go at ten times the natural frequency!!! :shock: :!: No way. It ain't gonna happen. The swing is tuned, and will resist all efforts to move at any frequency that it is not tuned to. Same with your 2-leaf MSM wall: it is tuned to a certain frequency that is LOWER than the lowest tone humans can hear. So at that frequency, the wall would basically be transparent, and allow the energy right through. But at all higher frequencies, it becomes progressively harder for sound to get through. The wall "fights back", and resists the passage of all frequencies, other than its natural resonant frequency. It is a tuned low-pass filter, just like a shelving EQ control on your console. So if you want isolation, you MUST build the wall correctly, such that it can do its job, and resist the passage of frequencies that you don't want to let through. So lets look at some scenarios here: First, if you don't put the second leaf in, then you don't have a system! If you only have one leaf in your wall, then it is NOT a tuned MSM system. It is just a bunch of mass. It no longer obeys the laws of tuned systems, and it now only obeys another part of physics, called "mass law". Mass law is not your friend. Basically, mass law says that you need an incredibly large amount of mass to get a little bit of isolation. And with only one leaf, mass law is all you have. Second, if you don't put enough mass on both leaves, then the resonant frequency of the tuned system is too high, and it lets through sounds that you actually want to block. So if you try to save money by using lightweight materials, or materials that are too thin, then it won't work. It will still block high frequencies, but it will not block lows. Third, if you don't make the gap between the walls big enough, then the resonant frequency of the tuned system is too high, and it lets through sounds that you actually want to block. So if you tried to save a few inches of space around the room but not using deep cavities, well, it wont work. Just like above, it will still block high frequencies, but it will not block lows. And finally, you can actually improve the performance by adding a "damper" to the circuit (kind of like putting a choke into a tuned RC system). In a 2-leaf MSM wall, the best damper is plain old fluffy pink insulation, or plain old mineral wool insulation. Filling the cavity with insulation damps the resonance, lowers the resonant frequency even more, and makes the wall isolate better. OK, so if you change ANY parameter in the tuned system, you change the tuning! It turns out that you get optimum isolation when the mass is divided about equally between the two leaves, so if you tried to make one leaf light weight (to save money for "that room"), while the "other" leaf is heavy (because you thought the "other" room needs more isolation, so you'd make a thicker wall), well, all that you succeeded in doing is, raising the resonant frequency of the system, and reducing your isolation for BOTH rooms. In other words: If you change anything, then you make EVERYTHING worse, not just one room. OK, back to your basic problem: If you have a room that needs no isolation at all, such as the lounge, office, kitchen, etc., then the solution is simple: Don't isolate that room! Keep it outside the outer leaf (or rather, make it part of the outer leaf), and don't build any inner leaf for it! Problem solved! Use your money to ONLY isolate the rooms that need it: the control room, the live room, and the iso booth. So design your building such that there is one single common "leaf" around all of those, and inside that common leaf you then build your three separate, independent inner-leaf rooms. Each room, in reality, is just an inner leaf. The "outer leaf" for each wall is either the actual common outer leaf shell, or it is the inner leaf of the next room.

AND, since I clearly have two leafs in between the control room and live room, control room and iso booth, and iso booth andlive room, adding the outer leaf to isolate the lounge/wet bar from the live room/control room area will add more isolation to the lounge/wetbar than necessary.

No it wont: Adding that outer leaf is what completes your system! Without that, you have no system, and no isolation for any of the rooms.

Again, I don't care too much if the drums are not isolated by 50-60 DB to someone who is sitting in the lounge area.

That's fine, but there's no way that you can only isolate in just one direction from a room, or only isolate one wall: That goes back to the aquarium analogy: It is all or nothing. If your wall between the drum booth and the lounge is not a 2-leaf MSM system, then neither is anything else. So you either put the drum booth outside the isolation shell, along with the lounge, or you put it inside. If it is outside, then it is not isolated at all, and drum sound will be heard all around the house, and by the neighbors. If it is inside, then it is isolated and drum sound will not be heard in the lounge, and will also not be heard in the rest of the house or by the neighbors. You can't put the drum room partly in and partly out of the isolation system! It is not physically possible. That would be like trying to boost and cut one channel on your console at the same time! It cannot be done. Either you can boost, or you can cut, but you cannot do both at once.

I want to save some money by not fully finishing the lounge/wet bar area

Fine, then leave the lounge and bar OUTSIDE of the isolation shell! Problem solved! If it doesn't need isolating, then don't isolate it! Just isolate what actually does need it.

by only buying 1 solid core door for each entrance way,

A single solid core door is not much use in an MSM system (unless you are talking about Rod's "Superdoor"!). There are two leaves: each leaf needs its own door. So for each room that is INSIDE the isolation shell, there will be two doors. And for each room that is OUTSIDE the isolation shell, there only needs to be one door.

maybe building standard walls for the specific walls of the control room and live room that lead into the wetbar/lounge area respectively, is all I need to achieve the amount of isolation I need?

Nope! A standard wall (2x4 studs with 12mm drywall nailed to both sides) will give you about 25 to 30 dB of isolation, in real-world conditions (Maybe 31 or 32, if you test it in a laboratory): that's not much. A double-stud MSM wall can easily get you 50 dB, which is about one hundred times better than 30 dB. If you design and build it right, it can get you 60 dB, or even more. 60 dB is one thousand times better than 30 dB... (In order to isolate to 60 dB, the wall must absorb one thousand times more energy than for 30 dB). So, to recap and simplify: only isolate the rooms that need it. Build a single outer leaf shell around the empty space where those rooms will go, which includes sealing and beefing-up the subfloor above you, sealing and perhaps beefing up the existing walls, and building new single-leaf walls to complete the shell. (You need to make sure that all of the existing walls that will be part of the outer leaf are only single-leaf). With your outer shell now completed, you build one set of stud framing for your control room (four new walls plus new ceiling) and put drywall on only one side of that framing. Then you build one set of stud framing for your live room (four new walls plus new ceiling) and put drywall on only one side of that framing. Then you build one set of stud framing for your iso booth (four new walls plus new ceiling) and put drywall on only one side of that framing. Add doors, windows, HVAC and electrical. DONE! So you now have three separate "inner-leaves" inside the single common "outer leaf". Each wall is part of a tuned MSM system with its "pair", on the other side of the gap between them. No room touches any other room. No room touches the existing structure. Presto! You have three properly isolated (and very well isolated) rooms. Add suitable acoustic treatment to each, decorate to taste, and make music! :shot: :D - Stuart -

Stuart, thanks so much. Listen, it is a lot to completely understand right now, can you answer this specific set of questions like right now?! I have someone coming over to move my bathroom from where you see it in the actual pictures in the beginning of this thread to where it is in this NEW design BELOW, in about 16 hours. Can I even do what you are talking about in the layout I have here without losing much space? Does what you are talking about work with my current layout with those stupid stairs in the middle?! heeeeeelp!! :!: :shock: Like.. should I build that one main wall AROUND the stairs? Can I even do that? ..or should I build it in FRONT of the stairs? ..or is it not possible with this current design?? :!: NOOOO!!! (where is the explosion smiley?!)