Right! That's a form of sway brace. Here's another type:they have advised me to go with this isolation bracket for what I am trying to do. This will be a much better suited product for what I'm trying to do.
Yup! "amazing" ain't cheap!"I want this studio to amaze people. 'That'll do' doesn't amaze people" haha. That being said at 8$ a pop...they're not cheap lol
Great!I've decided to start using Sketchup so that I can best explain what I'm trying to do/build. I'll be posting some pictures as soon
And before you even get to consider your options, you first need to measure how loud you are, how quiet you need to be, and how much isolation you need. All of those in decibels.Before I start drafting plans of my walls/floors.etc I do have a few questions regarding decoupling and dampening. I've done some research but can't seem to get a clear answer on what are my best options.
It's fine as long as you realize that you won't get good isolation, unless you are willing to invest a lot of money. The room itself can be great, but it just won't be isolated very well.Once again I do understand that building a studio above a garage isn't the best option but it's all I have so I'm trying my best to do things right.
Yes, correct. You already have the garage, so you already have one of the stud walls. You only need to add the second one. You will build a stud frame that does NOT touch any part of the existing building, except the floor. And you will put drywall on only ONE side of that frame.Question 1) I'll def be using the double stud wall concept...this is what makes my walls/rooms decoupled from each other correct?
Yes. It is the weak link in two different aspects: 1) isolation. 2) Structural integrity. The second one is a big issue, because there is a limit to how much extra load you can place on that floor before it collapses. So you will need to get a qualified structural engineer in to look at that floor, tell you what the maximum live load and dead load are, how much live load and dead load it is supporting right now, and therefore how much extra load you can put on it. That translates into how much total mass (weight) you can add, which defines the maximum isolation you can get. The fist issue above, is also about isolation, but this time it is the isolation that the floor itself provides. It is a single-leaf, and therefor is governed by Mass Law, which isn't very helpful. That implies that your maximum isolation is limited by the floor, regardless of how much extra load it can handle.Question 2) I'm framing these double walls on an existing wooden sub-floor (over my garage), it's obvious that my weakest link here is my wooden floor correct?
It would be nice, but you can't. All the walls will be resting on, and firmly attached to, the same floor.Question 3) Framing walls directly on top of the sub-floor I'm wondering if I need to do anything special to help/address flanking from one room to another through the floor.
Only if the structural engineer says that you can!I understand that I can add mass to my floor
And even then, adding mass to a single leaf floor does not help much. You have to DOUBLE the mass to get a measly increase of 4 or 5 dB.It might help a little, but not a huge amount. And you'd have to take great care to ensure that the wall really does float. Lots of math involved in that!what about the walls themselves? Would it be a good idea to put some neoprene rubber under at least 1 wall's bottom plate, or maybe both?
Yes, and it would ALSO be transmitted through the floor directly, regardless of what the walls do! The sound inside the room hits ALL of the boundary surfaces of the room: the walls, the ceiling, and the floor. Since the sound will be getting into the floor like that anyway, and thus into the adjacent rooms, there's not much point in trying to prevent the sound from getting into the walls and taking a longer path, when it already go there in any case!I have a feeling I'm not understanding this decoupling/dampening thing properly but in theory it seems like a good idea since any noise vibration coming from one room could easily be transmitted to another room through the existing floor.
... then it would probably collapse! 3/4" MDF weighs roughly three pounds per square foot. Let's say you added 5 layers of that, it would be 15 PSF. Let's say your floor measures 26' by 28' feet, which is 728 square feet. at 15 PSF, that implies a load of roughly eleven thousand pounds! That approximately the weight of half a dozen Smart cars, or three mid-size cars AND a compact car, or two full-size SUV's, or a box truck fully loaded with fuel, cargo and passengers! Do you really think your floor would be able to hold that? Would you be happy parking several cars or a loaded truck on that floor, then standing under it, in the room below?I guess that if I was to add mass (a few layers of 3/4" MDF sandwiched in GG) to my existing sub-floor
Nope, not really. It would still be a single-leaf floor, and it would already be so heavy that you would probably not be able to add any walls, ceiling, doors, windows, treatment, HVAC, furniture, or gear...then use a rubber underlayment and some laminated flooring it would help solve that problem right?
Ok! I will attempt at taking my own measurements but just to give a general idea I'm positive that drums are going to be the loudest thing in that studio. I'd say when I'm playing hard I'm probably peaking at around around 120dB (hard rim shots and cymbal crashing) but I would probably average it out at 110db. Obviously my kick drum and bass amps are going to be the hardest to isolate since they're in the low frequency range but that's fine.You first need to measure how loud you are, how quiet you need to be, and how much isolation you need. All of those in decibels.
Yep! I get that part. I am willing to invest a decent/reasonable amount of money since most of the labor will be done by myself.It's fine as long as you realize that you won't get good isolation, unless you are willing to invest a lot of money. The room itself can be great, but it just won't be isolated very well.
That part I understand!You already have the garage, so you already have one of the stud walls. You only need to add the second one. You will build a stud frame that does NOT touch any part of the existing building, except the floor. And you will put drywall on only ONE side of that frame.
Understood!Floor is the weak link in two different aspects: 1) isolation. 2) Structural integrity. The second one is a big issue, because there is a limit to how much extra load you can place on that floor before it collapses. So you will need to get a qualified structural engineer in to look at that floor, tell you what the maximum live load and dead load are, how much live load and dead load it is supporting right now, and therefore how much extra load you can put on it. That translates into how much total mass (weight) you can add, which defines the maximum isolation you can get. The fist issue above, is also about isolation, but this time it is the isolation that the floor itself provides. It is a single-leaf, and therefor is governed by Mass Law, which isn't very helpful. That implies that your maximum isolation is limited by the floor, regardless of how much extra load it can handle.
Ok!It would be nice, but you can't. All the walls will be resting on, and firmly attached to, the same floor.
Well that sucks haha! I'm confused...I thought having a sub-floor on top and dry wall on the other side make the floor a double leaf?Only if the structural engineer says that you can!
Every little bit helps I guess. I started putting together a spreadsheet of the total weight of each walls so that I can properly calculate and compare with the product specs. I do have a lot of that Iso-Sill product at home already so if it can be used then great. I was going to use it for my home theater in my basement but can always order more.It might help a little, but not a huge amount. And you'd have to take great care to ensure that the wall really does float. Lots of math involved in that!
Right!Yes, and it would ALSO be transmitted through the floor directly, regardless of what the walls do! The sound inside the room hits ALL of the boundary surfaces of the room: the walls, the ceiling, and the floor. Since the sound will be getting into the floor like that anyway, and thus into the adjacent rooms, there's not much point in trying to prevent the sound from getting into the walls and taking a longer path, when it already go there in any case!
Ok i wasn't thinking 5 layers, more like 2 if the structure can safely take it, but I do understand your point...I need to make sure my floor can safely take whatever I end up putting on top of it.... then it would probably collapse! 3/4" MDF weighs roughly three pounds per square foot. Let's say you added 5 layers of that, it would be 15 PSF. Let's say your floor measures 26' by 28' feet, which is 728 square feet. at 15 PSF, that implies a load of roughly eleven thousand pounds! That approximately the weight of half a dozen Smart cars, or three mid-size cars AND a compact car, or two full-size SUV's, or a box truck fully loaded with fuel, cargo and passengers! Do you really think your floor would be able to hold that? Would you be happy parking several cars or a loaded truck on that floor, then standing under it, in the room below?
I think from the specs of my floor I can do max DL of 15PSF...I'll get confirmation of all this from the engineer. The floor currently doesn't support anything...it's just one big blank unfinished room.I guess I'll have a better idea of what my options are once I get the final numbers from my engineer.Nope, not really. It would still be a single-leaf floor, and it would already be so heavy that you would probably not be able to add any walls, ceiling, doors, windows, treatment, HVAC, furniture, or gear...
Hope to be able to share some time next week.Cool! That's good news.I'm going to make sure I follow the right path in doing things.
Right. That's all correct, and realistic. When you do measure, make sure that you use a good quality hand-held sound level meter, and set it to "C" and "Slow". But your estimates are about right, for sure.I'm positive that drums are going to be the loudest thing in that studio. I'd say when I'm playing hard I'm probably peaking at around around 120dB (hard rim shots and cymbal crashing) but I would probably average it out at 110db. Obviously my kick drum and bass amps are going to be the hardest to isolate since they're in the low frequency range
Unfortunately, it's all the same thing. Different aspects, but still the same. Consider this paradox: If it were possible to have fantastic isolation between the LR and CR, but poor isolation between either of those rooms and the outside world, apart from needing Harry Potter and his magical crew to achieve that, you'd have the impossible situation where a loud noise could leave the poorly isolated LR and arrive in the outside world, yet it would magically not be allowed to get into the poorly isolated CR...I don't really care so much about the noise I'd be making outside. The control room is where I want to be as isolated as possible
Ummm.... Ain't gonna happen! If you need good isolation between rooms, then you also need good isolation between the rooms and the outside world. It's a package deal. It would be sort of possible to have the opposite situation: Poor isolation between rooms, but good isolation to the outside world... however, I'm not sure why anybody would want that, and it would be expensive! You'd have to do all the math to be sure, but 40 dB isolation is probably realistic (about twice as good as a typical house wall, subjectively), and maybe 50 dB if all the planets happen to align on a sunny day with the wind blowing in the right direction and the moon at exact right angles and a unicorn walks through your studio at the same time, while pixies are sprinkling dust on the walls....I do realize that I won't be able to get great isolation because of the location of the studio but I'm wondering what would be possible and realistic to achieve with my current configuration.
I'll get back to that point shortly, so do hold on to it, mentally!To be clear I am willing to spend some money on making things safe and adding additional support for a heavier floor, but realistically pouring 4-6" of concrete on my floor is not an option. hahaha.
OK, that's reasonable but not fantastic. You'll be taking up a large chunk of that with a load that's actually dead load (new walls, ceiling, treatment, etc), but your engineer will probably tell you that this is fine, as long as you then take great care to monitor your REAL live load, as you add furniture, people, gear instruments, and also take into account possible wind loading and other true "live" loads...Maximum Allowed Unfactored Live Load for this particular floor: 48 PSF
That would be a coupled two-leaf system, not a true MSM system. It acts more like a single leaf than it does like a two-leaf, although it does have some characteristics of both.Well that sucks haha! I'm confused...I thought having a sub-floor on top and dry wall on the other side make the floor a double leaf?
OK, here's where we get back to the "6" concrete slab" comment I promised you above. And this is the part that you won't like too much.... it's also the part that the purveyors of "plywood deck floated on our magic rubber pucks" don't tell you. Here's how it goes...Ok i wasn't thinking 5 layers, more like 2 if the structure can safely take it, but I do understand your point...I need to make sure my floor can safely take whatever I end up putting on top of it. ... I think from the specs of my floor I can do max DL of 15PSF...I'll get confirmation of all this from the engineer. The floor currently doesn't support anything...it's just one big blank unfinished room.
In other words, you'd need to have 31 layers of 5/8" OSB on your floor, to get enough mass. 
But if you wanted to go with the 30 PSF option, you'd "only" need 16 layers of OSB to get there.... Assuming you weigh about 180 pounds, and that your weight will be spread across four square feet of floor, just by stepping on that floor you increase the loading from 6 PSF to 51 PSF Gulp! I think you see where this is going.... You just flattened your rubber pads into oblivion! They are now squashed flat, and don't float. ) and get your engineer to check it all over to make sure that you'll be within the limits of your floor structure. You might even want to consider "beefing up" your floor structure with additional joists in between the existing ones, or sistered to them, to get you more capacity, and therefore more isolation.I guess I'll have a better idea of what my options are once I get the final numbers from my engineer.
Hint: You need to know the Three Magic Chants that you need to repeat over and over with SketchUp to make it work: "Select geometry, Make Component", then "Entity info - Assign to layer", and "Add new scene". These incantations have to be chanted repeatedly at the dead of night while hunched over a steaming hot keyboard, with your glaring-red eyes blurrily gazing unseeingly in the approximate direction of the dimly glowing screen, and the syllables must be muttered softly in an incoherent flat monotone in the key of F#, as your fingers numbly poke at worn-out keys, and you grate the mouse unfeelingly over the same deeply etched time-worn path in the surface of your desk....I'm doing good progress on Sketchup and I'm almost done with the current layout of the studio.
Repeat, night after night, endlessly, for centuries, and your wish may eventually be granted.... 
Yeah i guess I was expecting that...it only makes sense.Unfortunately, it's all the same thing. Different aspects, but still the same. Consider this paradox: If it were possible to have fantastic isolation between the LR and CR, but poor isolation between either of those rooms and the outside world, apart from needing Harry Potter and his magical crew to achieve that, you'd have the impossible situation where a loud noise could leave the poorly isolated LR and arrive in the outside world, yet it would magically not be allowed to get into the poorly isolated CR...
So whatever number you come up with for your total isolation, will be roughly the same between rooms as it is between either room and the outside world.
I see 40dB as a decent number for what I'm trying to achieve. There won't always be loud drum playing. It's going to be mostly acoustic and electric guitar, along with some bass but overall the level can be kept to a reasonable level and def lower than 100dB. The times where drums and really loud playing can be managed. I'm going to keep the 50dB number as a gift from the heavens where pixie dust unicorns haha.You'd have to do all the math to be sure, but 40 dB isolation is probably realistic (about twice as good as a typical house wall, subjectively), and maybe 50 dB if all the planets happen to align on a sunny day with the wind blowing in the right direction and the moon at exact right angles and a unicorn walks through your studio at the same time, while pixies are sprinkling dust on the walls....
Ok so I got some numbers back from the guy who did all my house plans. The actual number is LL 40 PSF and DL 15 PSF. This is not good news but it's still manageable to accomplish something decent I think. The architect is working on giving me a few options in terms of adding structural support and said he would suggest from isolation options as well. That last part I'm not too sure about since I'm positive this guy has never built a recording studio on top of a garage haha so I'll take his advice on the second part with a grain of salt. He did however agree that concrete is the most efficient way to isolate.RE: Max Live Load.....OK, that's reasonable but not fantastic. You'll be taking up a large chunk of that with a load that's actually dead load (new walls, ceiling, treatment, etc), but your engineer will probably tell you that this is fine, as long as you then take great care to monitor your REAL live load, as you add furniture, people, gear instruments, and also take into account possible wind loading and other true "live" loads...
Right!! Ok that makes more sense...I wasn't taking the true MSM into the mix but yeah I got a bit confused. All good now!That would be a coupled two-leaf system, not a true MSM system. It acts more like a single leaf than it does like a two-leaf, although it does have some characteristics of both.
That's an awesome way to explain and understand! I knew in the back of my mind that concrete was going to come back to hunt me so I can't lie and say that I didn't expect it haha. I've taken the steps already to start figuring out the MAX amount of concrete I can pour in that room with minimal added bracing & support.OK, here's where we get back to the "6" concrete slab" comment I promised you above. And this is the part that you won't like too much.... it's also the part that the purveyors of "plywood deck floated on our magic rubber pucks" don't tell you. Here's how it goes...
Here's a graph that explains the problem in simple terms:
Right!! I'm thinking that tuning the floor anything below 40 Hz would be a bonus. I think the odd times where a bass would be played loud can also be managed. This all makes a lot more sense to me though. This stuff is gold!So if you need to isolate kick drums, which are often tuned around 80 Hz, then your floor should be tuned no higher than 40 Hz, which is one octave lower. If you want to isolate bass guitar, which easily goes down to 36 Hz (5 string bass), then you'd need to tune your floor no higher than 18 Hz. Let's assume this is the case, and now we can look at the graph.
Ok! So I'm thinking if I'm able to do 2.5" of concrete, that could give me around 30 PSF and even at 20 Hz I could float a floor on 2x4s no?The graph shows the frequency up the left hand side. You need something at 18 Hz, so draw an imaginary line across the graph a bit less than 20 Hz. You can now see that no matter how deep your air cavity is, the top two dashed lines are no use: you can never get a low enough frequency if your floor only weighs 5 PSF (pound per square foot) or 10 PSF. Not possible. However, at 30 PSF it is possible (the dotted line, third from the top): it looks like you would need to have an air cavity that is at least 4.5 inches deep, so you can't do it with 2x4's, as they are only 3.5" deep. You'll need to use 2x6's (which are 5.5" deep). Your other option is to go with an even heavier floor: the bottom curve on the graph, labeled 60 psf (solid line, not dashed). With that option, you can get a frequency of 18 Hz. with a cavity about 2" deep, so you could use 2x4s there.
I'm a little confused about the first option proposed. Do you mean just a floating floor for each individual room and walls beside the floor? I for sure understand that having all the walls on top of the floating floor would be ideal but is it really worth it vs floating the walls on the original sub-floor? the only reason I say this is because I framed a couple of walls to get a sense of the actual room sizes. They have only been temporarily fastened there and can easily be removed and disassembled but if it's not a big deal it would be great to leave them there. Again if it makes such a big difference then I'll adjust the walls to sit on top of the floating floor.So that's the issue. Floating a light-weight floor is not a viable solution. You need huge mass to float a floor successfully. It is certainly possible to float a floor, and companies like Mason Industries make devices to do that, but it only works with very high mass for the floor deck, such as 3 or 4 inches of solid concrete.
There's another option here, which is even better: build your inner-leaf walls on top of the floor! In that case, the entire room is floated. The calculations for the springs are a bit more complicated like that, but the total floated mass is even greater, so variations from people standing on the floor and moving gear in and out are even lower, as a percentage of the total floated mass. That's a lot more expensive, of course, and more complex, but if you really do have a need for extra high isolation, that's as good as it gets.
Yep! I'll be waiting on the options from my architecture (who deals with a particular engineer) and will post them once I hear back from them. Should be within the next week or so. That being said, I will take this time to work on some music until I can get back into planning mode before I start doing some more work.However, you'd have to do a lot of math here (which you are already doing!
Hahaha it was one of the first things I learned in there. Create group and Create component are a pretty common thing lol. It's starting to look good. I've got my HVAC main trunk on there so I can start laying out where I can install the take-offs for the silencers and all that stuff. It's coming along...still hoping to post it up soon.Hint: You need to know the Three Magic Chants that you need to repeat over and over with SketchUp to make it work: "Select geometry, Make Component", then "Entity info - Assign to layer", and "Add new scene". These incantations have to be chanted repeatedly at the dead of night while hunched over a steaming hot keyboard, with your glaring-red eyes blurrily gazing unseeingly in the approximate direction of the dimly glowing screen, and the syllables must be muttered softly in an incoherent flat monotone in the key of F#, as your fingers numbly poke at worn-out keys, and you grate the mouse unfeelingly over the same deeply etched time-worn path in the surface of your desk....
this guy has never built a recording studio on top of a garage haha so I'll take his advice on the second part with a grain of salt.
Architects actually do get a bit of theoretical acoustics during their studies... maybe a dozen hours or so! ( ) ... and most of that is on architectural acoustics.... The amount of time they get on specifically designing recording studios, is probably somewhere between zero and nothing, but it might even be as high as zip, or even nada! It might even be Zilch! Cool! Glad you agree! John and I do happily also accept donations in gold... preferably in the form of small ingots or large coins...This stuff is gold!
Theoretically, yes... borderline, but yes. But you don't actually need 2x4's at all! You just need that size air cavity under your slab: 3.5" I just used 2x4's in the above diatribe so as to fit in with the fairy-tale spun by the "rubber puck" people, and show why their faeries are actually demons in disguise.... What you really need under your slab, is not demons or 2x4's, but proper springs and and air. The correct springs, of course! Not just any springs... Mason Industries is one of the companies that makes that type of spring.Ok! So I'm thinking if I'm able to do 2.5" of concrete, that could give me around 30 PSF and even at 20 Hz I could float a floor on 2x4s no?
Right. That's the option for situations where you can't put the walls on the slab, for whatever reason. Of course, it's better if you CAN do that, by far, but sometimes you can't.Do you mean just a floating floor for each individual room and walls beside the floor?
You certainly can, yes! And that would give you the highest possible isolation, since each room would be floated independently.This also gets me thinking. Could I potentially pour individual slabs for each room instead of one big slab for the perimeter of the entire studio?
I would also suggest that you talk to the guys at Mason Industries, or one of their competitors, to find out what they think. They make the springs that you need to float your slab. They can do all the calculations for you, and tell you what you'll need in your base structure, how many springs you'll need, what type, where to put them, etc.Yep! I'll be waiting on the options from my architecture (who deals with a particular engineer) and will post them once I hear back from them.
haha That's pretty much what I was thinking!Architects actually do get a bit of theoretical acoustics during their studies... maybe a dozen hours or so! (
If I have any gold coins left after my build I'll make sure to send some over.Cool! Glad you agree! John and I do happily also accept donations in gold... preferably in the form of small ingots or large coins...
Ok, I wasn't understanding all this properly but now I get it. After looking at the spring options...I understand how they work and raise the slab. Very very cool stuff!! My only problem now is that after checking the specs off the Mason website...they require a slab with a minimum thickness of 3" so that's both good and bad for me I guess.Theoretically, yes... borderline, but yes. But you don't actually need 2x4's at all! You just need that size air cavity under your slab: 3.5" I just used 2x4's in the above diatribe so as to fit in with the fairy-tale spun by the "rubber puck" people, and show why their faeries are actually demons in disguise.... What you really need under your slab, is not demons or 2x4's, but proper springs and and air. The correct springs, of course! Not just any springs... Mason Industries is one of the companies that makes that type of spring.
Ok, if it's better...I'll just put my walls on top of the new slab.Right. That's the option for situations where you can't put the walls on the slab, for whatever reason. Of course, it's better if you CAN do that, by far, but sometimes you can't.
This is great because it will bring the total weight down a bit since I won't have to pour anything in between the rooms. Plus it would be easier for me to pour one room at a time.You certainly can, yes! And that would give you the highest possible isolation, since each room would be floated independently.
Will do!! I've already started looking at all their options and they make some really cool things.I would also suggest that you talk to the guys at Mason Industries, or one of their competitors, to find out what they think. They make the springs that you need to float your slab. They can do all the calculations for you, and tell you what you'll need in your base structure, how many springs you'll need, what type, where to put them, etc.
It's taking a bit longer than expected but I'm sure that's not uncommon haha.
But it also means you are doing it right. If it were going fast, then you'd almost certainly be doing it WRONG! Take your time, and do it completely, and in detail. That's the only sane way to design a studio!First question: Why do you want an operable window in a studio? Air movement will be handled by your HVAC system, not by a window that opens. In fact, having just one window that opens is not going to move any air at all!I really really want to keep that window and have it be functional as well but I'm wondering if that's possible or not.
... and that implies that you need a LOT of isolation! That's the only reason why you'd take that approach. It also implies that you have a very decent budget. Which brings us back to the question: Do you really want to trash your major investment in a floating concrete slab, by putting in an operable window?The goal is to build a floating concrete slab and frame walls for the CR on top of it
... assuming that you have enough mass up there, and a large enough air gap, and enough damping, to match the isolation that you'll get from your expensive floated slab.... all of which would be negated if you put in an operable window...Based on previous replies from Stuart, I should be able to use my existing ceiling by decoupling it with Hat Channel and clips.
You can have windows in your room, provided that they are not operable, and provided that they are designed properly, and provided that they are not in the way of any point in the room that would need treatment.I'm hoping something can be done to keep the window as is.
I'll admit I was quite shocked at all this information I found about building a studio. I figured a few walls a bit more drywall and we're good! haha Anyways, yes I've just accepted that this will take a lot more time than I had hoped for but that's fine, I don't plan on going anywhere and this will just be better for costs as they don't need to happen at once...it'll be a progressive build! heheBut it also means you are doing it right. If it were going fast, then you'd almost certainly be doing it WRONG! Take your time, and do it completely, and in detail. That's the only sane way to design a studio!
It's not for air movement and I guess it's not so much about it being operable but a lot about having the natural light. Could I seal it, leave it as is and then put in another "special" one in the inner wall?First question: Why do you want an operable window in a studio? Air movement will be handled by your HVAC system, not by a window that opens. In fact, having just one window that opens is not going to move any air at all!
Well...isolation has to be good 40db+ if possible from the rest of the studio but for the outside world...I couldn't care less. I was thinking if I was to frame my inner leaf window frame as close as possible to my outer leaf frame without touching of course and putting some sort special rubber seal in-between both frames. Gah..I guess i'm dreaming thinking this might work? haha too bad because that wall is facing and outside wall and doesn't face the rest of the studio.Second question: How much isolation do you need? An operable window is a weak point for isolation, and since isolation is only as good as the weakest point, you would be placing a limit on how much isolation you can get, if you install an operable window. Not to mention the minor detail that as soon s you open the window, you then have ZERO isolation....
Yeah I see where you're going with this. I just hope I can just seal it and leave it as is and possibly just put another thick glass in my inner leaf wall. I can build all the custom frames so that's not a problem. Again I only care about isolation in the CR, not the outside world, so I'm hoping I can just build a custom frame/window for the CR.... and that implies that you need a LOT of isolation! That's the only reason why you'd take that approach. It also implies that you have a very decent budget. Which brings us back to the question: Do you really want to trash your major investment in a floating concrete slab, by putting in an operable window?
The clips will be fasten to 1x3 furring strips which gives a 3/4" gap + clips + hat channel and then I was going to do 2 layers of 5/8" with GG. I'd say the air gap between the enermax panels (seen in the pics in my first few posts) and the drywall would be around 2" to 2.5".... assuming that you have enough mass up there, and a large enough air gap, and enough damping, to match the isolation that you'll get from your expensive floated slab.... all of which would be negated if you put in an operable window...
Yep! It's an eye-opener, isn't it? It gets your attention, for sure. If only sound would behave the way we expect it too, intuitively, instead of the way it really does!!! Darn those rules of physics...I'll admit I was quite shocked at all this information I found about building a studio. I figured a few walls a bit more drywall and we're good! haha
Cool! Then it should not be a problem. As long as you have it all sealed up, 100% air-tight, and also that there's enough mass in the glass (thick enough), then you can do that.It's not for air movement and I guess it's not so much about it being operable but a lot about having the natural light.
Could I seal it, leave it as is and then put in another "special" one in the inner wall?
Exactly. Both panes (the existing outer one, and the new inner one) need to have some decent mass (thickness), so you might need to replace the glass on the existing one with thicker stuff when you seal it up, but apart from that, you have the right idea.It would be nice if it were possible to separate those two, but in reality they are closely related, not independent. Think of it this way: If you have poor isolation from the CR to the outside world, and poor isolation from the LR to the outside world, then any sound getting OUT of one room through the poor isolation will also be able to get back IN to the other room through the poor isolation.... Ooops!Well...isolation has to be good 40db+ if possible from the rest of the studio but for the outside world...I couldn't care less.
That would be a bad idea! You want your inner leaf as far away as possible form the outer leaf, at all points, not as close as possible! That's the only way you can tune the MSM resonance low enough to get good isolation at low frequencies...I was thinking if I was to frame my inner leaf window frame as close as possible to my outer leaf frame
... which would probably COUPLE the two frames together, instead of decoupling them, which is what you should be trying to do!and putting some sort special rubber seal in-between both frames.
Again, they are inseparable. That's sort of like saying: "I only care about how wet my elbow gets when I'm submerged naked in the swimming pool. I don't care about the rest of me." In reality, ALL of you will be wet: you can't get your elbows wet without also getting the rest of you just as wet. It all goes together. . . .Again I only care about isolation in the CR, not the outside world,
Immmm... you must have misunderstood something I said... Like that, you'd have a very thin air gap and thus a very high MSM resonant frequency, and thus lousy isolation in the low end of the spectrum.... You need a LARGE air gap, at lest 4" (more if you want good isolation).The clips will be fasten to 1x3 furring strips which gives a 3/4" gap + clips + hat channel and then I was going to do 2 layers of 5/8" with GG.
I think the window thickness might okay/decent as is. I noticed it's not a double pane window with an air gap. It seems to be just two windows with a glaze/film in the middle but I would think this would act as a single leaf window?Exactly. Both panes (the existing outer one, and the new inner one) need to have some decent mass (thickness), so you might need to replace the glass on the existing one with thicker stuff when you seal it up, but apart from that, you have the right idea.
Right! Sorry, I forgot 40db was what I could achieve with my floor as is....I'm sure it would be a lot better with a floating slab.40 dB isn't that much, by the way. A typical house wall (drywall on either side of 2x4 studs) will get you around 30 dB. And 40 dB isolation means that somebody singing or playing a quiet musical instrument (eg, acoustic guitar) would be clearly audible in the other room. An acoustic guitar can hit around 90 dBC fairly easily, so with 40 dB of isolation, that would be heard at around 50 dBC in the other room.... I'd suggest that you need a lot more than 40 dB isolation. Probably over 50 dB, maybe even shoot for 60.
Yep I'm confused again hahaha. First, would the mass I'm proposing be okay for ceiling (2 x 5/8"). Second for the air gap, I'm not sure how would I be able to get 4" gap in between my existing ceiling and drywall, unless I use some special ISO hangers? I'm starting to think a new ceiling on top of my floating walls wouldn't be that big of deal as 2x4 are cheaper than specialty brackets and I believe it would also be best for isolation.. I think I would be going this route instead now that I'm sold on the idea of a floating slab.Immmm... you must have misunderstood something I said... Like that, you'd have a very thin air gap and thus a very high MSM resonant frequency, and thus lousy isolation in the low end of the spectrum.... You need a LARGE air gap, at lest 4" (more if you want good isolation).