Sloped Live room ceilings - will 5 degrees give any benefits

[Krackle]

hi Folks, new here..failry simple question first and then an explanation of project and space im working on..

I'm currently working on framing several large sections of ceiling and I have a chance to slope these ceilings..

The ceilings are about 12-13 feet high and each section is approx 20' x17'..they are somewhat adjoining..separated by a very large steel beam that spans this space


The limitation on the slope i can do is about 5 degrees..can't do more than that.
Will i realize any benefit here at all?
Some tempering of Flutter issues..anything?

thanks!




((Overall project that is underway:

Im coming here to ask a few questions here and there regarding my build out of a multi use space..about 50' X 28' with high-ish ceilings
I'm not taking this to an extreme studio live room design, just looking for things i can do along the way in this build out, im on a filry tight budget, doing most of this myself, and looking for practical ways to improve how the room sounds, and soundproofing..

In the near future I'll be interested in concepts on decoupling walls and ceilings, some bass trapping and sound control
you probably get the idea..much the same as a lot of folks here i would guess.

This space will be a live room - much of time for recording and some performance here and there..other uses as well ))

[Gregwor]

Welcome. Please fill out your profile fully. Read the forum rules.

The limitation on the slope i can do is about 5 degrees..can't do more than that.
Will i realize any benefit here at all?
Some tempering of Flutter issues..anything?

You will only really benefit from getting the maximum amount of room area possible, and that's important.

((Overall project that is underway:

Im coming here to ask a few questions here and there regarding my build out of a multi use space..about 50' X 28' with high-ish ceilings
I'm not taking this to an extreme studio live room design, just looking for things i can do along the way in this build out, im on a filry tight budget, doing most of this myself, and looking for practical ways to improve how the room sounds, and soundproofing..

In the near future I'll be interested in concepts on decoupling walls and ceilings, some bass trapping and sound control
you probably get the idea..much the same as a lot of folks here i would guess.

I won't repeat what I've written a hundred times on the forum, but I will just ask you to read my signature and consider stopping your build until you fully plan it out. You mention that you're on a fairly tight budget. If that is true, then I will say that you will save yourself a TON of money if you plan your build first. That means 3D modelling it, posting your design here and getting contributing members to give you their thoughts about it so that you have the chance to change things in the computer realm before making major mistakes in real life that will cost you a lot of money to fix.

Greg

[Soundman2020]

Hi there "Krackle". Welcome!

Please read the forum rules for posting (click here). You seem to be missing a couple of things!

The limitation on the slope i can do is about 5 degrees..can't do more than that.
Will i realize any benefit here at all?
Some tempering of Flutter issues..anything?

Not really, no. There's empirical evidence that you need a difference in angle of at least 12° between opposite surfaces in order to control flutter echo, so 5° is not going to do much (unless you also want to slope the floor by 7° ).

Also, you are going to need some type of treatment on the ceiling anyway, so if you do that right, that should take care of any floor-ceiling flutter. So it would be pointless to wast time trying to angle the ceiling, even if you could get 12°.

my build out of a multi use space..about 50' X 28' with high-ish ceilings

That's a nice size room! 1400 ft2 is excellent for a live room! You can get a pretty large bunch of musicians in there, with lots of instruments and gear. What type of music (genre) will you be rehearsing/ tracking in there?

I'm not taking this to an extreme studio live room design, just looking for things i can do along the way in this build out,

OK, but a room that big is going to have a fairly long RT60 time, likely too long for most types of music (except maybe cathedral choirs and church pipe organs), so you will need fairly extensive treatment to get it into a range that is usable for typical music. There's differing opinions, but in a study done a few years back, most professional musicians prefer a decay time of around 700 - 900 ms for rehearsal, and around twice that for a large concert halls. So you should probably be aiming for something in the region 1 second to 1.5 seconds. That's a common time for "performance spaces". With your size room, depending on how it is built, the time is likely much longer than that, so you are going to need a fair amount of treatment.

Your room is rather different from a typical home studio or project studio: it's big enough to be considered in the category of "large room", acoustically speaking.... Or nearly so. That's a different area of acoustics from the typical "small room" acoustic situations you see in most places here on the forum. Some of the "rules of thumb" that you hear so often here don't really apply to your room. Some do, but others don't.

and looking for practical ways to improve how the room sounds, and soundproofing..

Treating a large room is easier than treating a small room in some aspects, because you are not subject to the typical modal issues that plague small rooms. However, it's more complex in other aspects, simply due to the total surface area of the walls, floor and ceiling, and the total room volume. Thus, treating your room will involve much less in the way of "bass trapping", and a lot more in diffusion, as compared to home studios.

Now.... "soundproofing"... Hmmm.... That's a term that most acousticians avoid, because it means different things to different people, and is impossible to achieve in any case! There's no way you can "proof" a room against all sounds: any sufficiently loud sound will get through any conceivable barrier. It seems you are talking about "isolation", which means attenuating the sound going out of the room and coming into the room?

In the near future I'll be interested in concepts on decoupling walls and ceilings, some bass trapping and sound control

Decoupling your walls AND the ceiling is, indeed, the correct way to isolate ("soundproof") a room, but it's going to be hard to do that after you already modify things with ceiling panels and interior treatment! If you need to isolate the room, then you should do that first, before you do any treatment, because you won't be able to do that afterwards. If you had any treatment installed, then you'd have to rip it all out in order to isolate. Isolating a room after it is treated is like trying to put your socks on after you already have your shoes on...

Also, unfortunately, isolating a room is expensive. Especially a room as large as yours, where you will obviously have some rather loud rehearsal and recording sessions going on. It's hard to isolate any room, small or large: harder still for large ones. And even harder to isolate rooms where acoustic instruments are being plaid. The worst of all is things like drums, bass, cello, and things like that, that put out a lot of energy in the low end f the spectrum. So if that's what you will have in your room, then you will need good isolation, and that's not going to be cheap.

I'm not trying to be a wet blanket here: just pointing out reality.

some bass trapping and sound control

Bass trapping in a large room that size won't be too much of a problem. You'll probably need some, of course, but nowhere near as extensive as for a small control room.

This space will be a live room - much of time for recording and some performance here and there..other uses as well ))

Great! I'd suggest that you start by defining how you want that to work it, and out some numbers to it. For example, determine how much isolation you have at present, how much you need in total, and therefore you can determine how much extra isolation you will have to build, in addition to what you have right now. Also define what acoustic response you want in your "live room", in terms of decay times, frequency response, etc. If you want to use the room for several different purposes, you should probably consider having variable acoustics in your room, such that you cna change the response as needed for different scenarios. Recording an entire symphony orchestra is rather different from recording a rock band, which is different again a small jazz ensemble, or R&B band... and different yet again from a single musician playing an acoustic guitar and singing. You would need very different acoustics for those. So having variable panels on the walls and ceiling would be a good way of dealing with that, with some being more reflective, some more diffuse, and some more absorptive.

Anyway, that's just some ideas... rather more than what you actually asked!


- Stuart -

[Krackle]

Welcome. Please fill out your profile fully. Read the forum rules.

The limitation on the slope i can do is about 5 degrees..can't do more than that.
Will i realize any benefit here at all?
Some tempering of Flutter issues..anything?

You will only really benefit from getting the maximum amount of room area possible, and that's important.

((Overall project that is underway:

Im coming here to ask a few questions here and there regarding my build out of a multi use space..about 50' X 28' with high-ish ceilings
I'm not taking this to an extreme studio live room design, just looking for things i can do along the way in this build out, im on a filry tight budget, doing most of this myself, and looking for practical ways to improve how the room sounds, and soundproofing..

In the near future I'll be interested in concepts on decoupling walls and ceilings, some bass trapping and sound control
you probably get the idea..much the same as a lot of folks here i would guess.

I won't repeat what I've written a hundred times on the forum, but I will just ask you to read my signature and consider stopping your build until you fully plan it out. You mention that you're on a fairly tight budget. If that is true, then I will say that you will save yourself a TON of money if you plan your build first. That means 3D modelling it, posting your design here and getting contributing members to give you their thoughts about it so that you have the chance to change things in the computer realm before making major mistakes in real life that will cost you a lot of money to fix.

Greg

Thanks Greg,

Yes, agree with that design first idea...and Im actually there in terms what i want to do within my budget..They are small in number but fairly large additions..

The main projects are
1) the second ceiling

2) a complete and decoupled 2x4 wall shell built inside the existing plaster walls..which are in very good condition and furred to the brick of the building..so, not insulated but thick, at least an inch...

3) some treatment for the room which include most inside corners and ceiling.

4) I am also going to try to isolate where walls meet floor and try to decouple the flooring, as best i can, where the two walls meet the floor (in the future i might also continue the inner wall, the shell wall, into the basement, which is a 6 foot short basement). there are some windows in this space and im also figuring a scheme for them..how to deal with the decoupled wall that meets the old well for the windows (plaster well).

Design wise, the dimensions/proportions of the room will not change..

[Krackle]

Hi there "Krackle". Welcome!

Please read the forum rules for posting (click here). You seem to be missing a couple of things!

The limitation on the slope i can do is about 5 degrees..can't do more than that.
Will i realize any benefit here at all?
Some tempering of Flutter issues..anything?

Not really, no. There's empirical evidence that you need a difference in angle of at least 12° between opposite surfaces in order to control flutter echo, so 5° is not going to do much (unless you also want to slope the floor by 7° ).

Also, you are going to need some type of treatment on the ceiling anyway, so if you do that right, that should take care of any floor-ceiling flutter. So it would be pointless to wast time trying to angle the ceiling, even if you could get 12°.

my build out of a multi use space..about 50' X 28' with high-ish ceilings

That's a nice size room! 1400 ft2 is excellent for a live room! You can get a pretty large bunch of musicians in there, with lots of instruments and gear. What type of music (genre) will you be rehearsing/ tracking in there?

I'm not taking this to an extreme studio live room design, just looking for things i can do along the way in this build out,

OK, but a room that big is going to have a fairly long RT60 time, likely too long for most types of music (except maybe cathedral choirs and church pipe organs), so you will need fairly extensive treatment to get it into a range that is usable for typical music. There's differing opinions, but in a study done a few years back, most professional musicians prefer a decay time of around 700 - 900 ms for rehearsal, and around twice that for a large concert halls. So you should probably be aiming for something in the region 1 second to 1.5 seconds. That's a common time for "performance spaces". With your size room, depending on how it is built, the time is likely much longer than that, so you are going to need a fair amount of treatment.

Your room is rather different from a typical home studio or project studio: it's big enough to be considered in the category of "large room", acoustically speaking.... Or nearly so. That's a different area of acoustics from the typical "small room" acoustic situations you see in most places here on the forum. Some of the "rules of thumb" that you hear so often here don't really apply to your room. Some do, but others don't.

and looking for practical ways to improve how the room sounds, and soundproofing..

Treating a large room is easier than treating a small room in some aspects, because you are not subject to the typical modal issues that plague small rooms. However, it's more complex in other aspects, simply due to the total surface area of the walls, floor and ceiling, and the total room volume. Thus, treating your room will involve much less in the way of "bass trapping", and a lot more in diffusion, as compared to home studios.

Now.... "soundproofing"... Hmmm.... That's a term that most acousticians avoid, because it means different things to different people, and is impossible to achieve in any case! There's no way you can "proof" a room against all sounds: any sufficiently loud sound will get through any conceivable barrier. It seems you are talking about "isolation", which means attenuating the sound going out of the room and coming into the room?

In the near future I'll be interested in concepts on decoupling walls and ceilings, some bass trapping and sound control

Decoupling your walls AND the ceiling is, indeed, the correct way to isolate ("soundproof") a room, but it's going to be hard to do that after you already modify things with ceiling panels and interior treatment! If you need to isolate the room, then you should do that first, before you do any treatment, because you won't be able to do that afterwards. If you had any treatment installed, then you'd have to rip it all out in order to isolate. Isolating a room after it is treated is like trying to put your socks on after you already have your shoes on...

Also, unfortunately, isolating a room is expensive. Especially a room as large as yours, where you will obviously have some rather loud rehearsal and recording sessions going on. It's hard to isolate any room, small or large: harder still for large ones. And even harder to isolate rooms where acoustic instruments are being plaid. The worst of all is things like drums, bass, cello, and things like that, that put out a lot of energy in the low end f the spectrum. So if that's what you will have in your room, then you will need good isolation, and that's not going to be cheap.

I'm not trying to be a wet blanket here: just pointing out reality.

some bass trapping and sound control

Bass trapping in a large room that size won't be too much of a problem. You'll probably need some, of course, but nowhere near as extensive as for a small control room.

This space will be a live room - much of time for recording and some performance here and there..other uses as well ))

Great! I'd suggest that you start by defining how you want that to work it, and out some numbers to it. For example, determine how much isolation you have at present, how much you need in total, and therefore you can determine how much extra isolation you will have to build, in addition to what you have right now. Also define what acoustic response you want in your "live room", in terms of decay times, frequency response, etc. If you want to use the room for several different purposes, you should probably consider having variable acoustics in your room, such that you cna change the response as needed for different scenarios. Recording an entire symphony orchestra is rather different from recording a rock band, which is different again a small jazz ensemble, or R&B band... and different yet again from a single musician playing an acoustic guitar and singing. You would need very different acoustics for those. So having variable panels on the walls and ceiling would be a good way of dealing with that, with some being more reflective, some more diffuse, and some more absorptive.

Anyway, that's just some ideas... rather more than what you actually asked!


- Stuart -

Thank you, Stuart! Excellent post and appreciated..

Yes, large room..I play rock and roll from loudish to fairly low key..I write and record with a friend for one..Also record demos with a local acoustic and electric players..folk, easy rock, raunchy rock..but not in your face or metal stuff..Sometimes some horns and and a violin, ukelele, cello or three.

As for the timeline of this...The room is stripped clean right now, it is a construction site. There is no treatment up, , Just tool stations and myself..

BTW, im experienced and realistic and experienced enough to understand that sound is gonna get out, even with some extra mass and basic de-coupling..even with a lot of mass.. im gonna piss someone off at some time..rule of the world!

As for budget..I do a lot of building , I own this very large building and have logged many years doing extensive and varied rehab on it. i also ran a lot of small crews doing various levels of construction to earn a living during periods of my life. Estimates on this will never be realized..I tend to look for the right solution for my needs by discussion and then filtering effectiveness of various schemes and weighing that against what i know the materials run per square foot.

This project is going to be lumber, drywall, screws and adhesive, hoping mainly for tips on decoupling walls and decoupling walls from floors and from each other via floor..in a sense..the design for me on this one comes down to a few engineering schemes for wht i know is about to happen...i hope that makes sense?

..and perhaps a second layer of drywall with a green glue type product...though..i do have to suss out the cost of green glue vs benefit..

I do have some hand drawn elevations and plans of the space which i will upload in a post here..I'll also send some photos..I will probably not jump on the learning curve of Sketchup..





Both of you gentlemen who responded so far have convinced me to stay with flat ceilings..


Thanks so much for your thoughtful post

[Soundman2020]

The main projects are
1) the second ceiling

2) a complete and decoupled 2x4 wall shell built inside the existing plaster walls..which are in very good condition and furred to the brick of the building..so, not insulated but thick, at least an inch...

Actually, that's not the best way of approaching it. You mention those as if they were two different things, but in reality they go together. I'll get back to that later, but this is a big issue... bigger than you think.

4) I am also going to try to isolate where walls meet floor and try to decouple the flooring,

Same as above... more comment below... but first, what is the floor right now? Is that a concrete slab? Is it mostly slab-on-grade? You mention a basement, but does that run under the full size of the floor? Or only partly? Anything else down there?

Thank you, Stuart! Excellent post and appreciated..

that's what we are here for!

Yes, large room..I play rock and roll from loudish to fairly low key..I write and record with a friend for one..Also record demos with a local acoustic and electric players..folk, easy rock, raunchy rock..but not in your face or metal stuff..Sometimes some horns and and a violin, ukelele, cello or three.

OK, so all sorts of genres, with all sorts of levels, up to maybe 115 dBC or so.

As for the timeline of this...The room is stripped clean right now, it is a construction site. There is no treatment up, , Just tool stations and myself..

Photos would be useful....

BTW, im experienced and realistic and experienced enough to understand that sound is gonna get out, even with some extra mass and basic de-coupling..even with a lot of mass.. im gonna piss someone off at some time..

That is, indeed, the common situation... However, it doesn't have to be like that, if you design it right and build it right... It is quite possible to isolate that to very decent levels...

As for budget..I do a lot of building , I own this very large building and have logged many years doing extensive and varied rehab on it. i also ran a lot of small crews doing various levels of construction to earn a living during periods of my life.

Great! So you have the tools, the manpower, and the expertise to do this right, and you know building materials and construction techniques well, too. That's a really good start.

Estimates on this will never be realized..I tend to look for the right solution for my needs by discussion and then filtering effectiveness of various schemes and weighing that against what i know the materials run per square foot.

I can add a bit of data to that, which should help. Clients who have built studios I designed tell me that their actual construction costs are in the range of maybe US$ 80 to 180 per square foot for a ground-up build, and about a quarter to half that for modifying an existing building. Very broad range, yes, but there's a very broad range of what people need for their studios. That seems to hold true across most of the USA. In your case, probably lower since you are in the industry, and you know where to find less expensive materials, and how to control labor costs. So maybe knock 10% off that.

This project is going to be lumber, drywall, screws and adhesive, hoping mainly for tips on decoupling walls and decoupling walls from floors and from each other via floor..in a sense..the design for me on this one comes down to a few engineering schemes for wht i know is about to happen...i hope that makes sense?

That makes perfect sense, and now I can get back to the point I made above, about your approach to isolation, with separate plans for the ceiling, the walls, the floor, the doors, windows, etc. Unfortunately, isolation doesn't work like that. Isolation is a system, not a bunch of parts. It is the way all the parts work together that matters, not so much the individual parts. So building a ceiling one way, a wall another way, then thinking about the floor at another time, then maybe the doors.... You probably won't like what I'm going to say here, but that approach is doomed to failure. You can't successfully isolate a room by looking at it as individual parts to be isolated separately, such as walls, ceilings, doors, etc. You can only successfully isolate it, by looking at it as a whole: a complete resonant system. Because that's exactly what it is!

The walls, floor, windows, ceiling and etc. all work together to create the overall isolation, and the total isolation can never be better than the weakest part. That's a key rule that should guide you here, and it is very logical. Let's say somebody built a room out in the open, and all the walls isolate to 50 dB, the doors are good for 45 dB, the windows are good for 60 dB, and the ceiling is good for 30 dB. What's the total isolation? About 30 dB. The weakest part sets the limit. In this hypothetical case, the ceiling is the weakest, at 30 dB, so all of the time, money and effort spent on building the other stuff to a higher level, is totally wasted.... unless the ceiling is modified for 50 dB, then it all makes sense again!

So how does that work in practice? As I mentioned it's a resonant system, and THAT is what creates the isolation: It's arises as a product of the arrangement of the parts, which TOGETHER form a resonant system. With such a system, the total isolation is far, far higher than the isolation produced by the individual parts, or even the sum of the individual parts. Resonance is a very powerful tool in acoustics. At the resonant frequency of the system, it does not isolate at all, and in fact it can amplify the sound, but at all frequencies greater than twice the resonant frequency, it isolates very well. So the key is to "tune" the system such that the resonance is no higher than half of the lowest frequency that you need to isolate. It's that simple. If you tune it wrong, or of you build it wrong so that it does not resonate, then you get lousy isolation. If you build it right, then you get good isolation.

So how do you tune it? Also simple: you build it as a "fully-decoupled two-leaf MSM" structure. Also sometimes referred to as a "room within a room", or even "box in a box". In other words, you need to have two "shells" or two "leaves", and they must not be connected to each other. You have an "outer leaf", and an "inner leaf", each of which is a completely self-supporting structure, and the two leaves do not even touch each other. You already have your outer leaf: the building itself. The walls, floor, ceiling, doors, windows, etc. form a complete "envelope" or "shell" that surrounds the empty air inside. That's your outer leaf. Then all you need to do is to build your "inner leaf" within that shell, consisting of four walls and a ceiling, with the associated doors and windows. That will be your inner leaf. As you mentioned, it will be stud-framed walls with drywall on only ONE side of the frame (not both), but the part you got wrong was the ceiling: your inner-leaf ceiling cannot be attached to the existing outer-leaf roof, and it cannot be built as separate panels between the outer-leaf trusses either. Ideally, the inner-leaf ceiling rests only on the inner-leaf walls, or at best it is a structure that is hung from the outer-leaf roof on suitable resilient mounts that are tuned to the right resonant frequency (the same as the one of the walls), and only has hard connections to the inner-leaf walls.

That's the basic outline: you have an outer box (the building), and you need to build an inner "box". The inner box is a complete, consistent, coherent, shell that stand on it's own, and it does not touch the outer leaf at any point: no hard connections. Both shells are sealed airtight.

How do you tune it? By adjusting the mass of each leaf, and the air gap between them, and the insulation that fills that air gap. There are equations and calculators for figuring that out. They will help you figure out the set of building materials that you need to build up the mass, and the size of the gap between the leaves, and the insulation, that is right to get the resonant frequency you need, and the isolation that you need. And to clarify one more time: it's not so much the individual parts of the wall or ceiling that do the isolating, but rather the system as a whole. The individual parts play a role, for sure, but it's the system that gets you the isolation. Tune it wrong, and it will isolate poorly. Tune it right, and it isolates well.

That's the way to do it: design it and built it as a properly tuned system. Then you can get very good isolation.

..and perhaps a second layer of drywall with a green glue type product...though..i do have to suss out the cost of green glue vs benefit..

Simple rule of thumb; Green Glue will get you very roughly as much benefit as an extra layer of 5/8" drywall. So if the installed cost of the drywall is higher than that of the GG, then go with the drywall. But if it isn't, or if drywall would add too much extra weight, or take too long to do, then go with the GG. It is simple, fast, and effective.

I do have some hand drawn elevations and plans of the space which i will upload in a post here..I'll also send some photos..

Cool! Looking forward to seeing those.

Both of you gentlemen who responded so far have convinced me to stay with flat ceilings..

And Andre too, over at GearSlutz! Listen to him: he's one of the most highly respected acousticians around. Very smart guy.

- Stuart -

[AVare]

It may be properly designed already, but I have read nothing about the HVAC, electrical, or wiring troughs.

Andre

[Krackle]

Morning folks,

My budget is extremely limited here..Im only, at this point, trying to make good decisions on basic methods of decoupling when installing a 'shell' wall..and also providing a sensible platform or separate base for the old plaster walls where they hit the floor.

Also, methods for decoupling corners..which i think I understand..not allowing new drywall to meet where planes change..filling gaps with a proper sound sealer?

Electrical will be surface except for the main feeds out of the breaker box.to ceilings, to baseboards, bathroom, galley kitchen..these are relatively short runs to each location where they get 'revealed'

There is a furnace in the basement and ducts going to floor outletsreturns..I plan on doing some modification of the ductwork but not sure where that's going yet..it's fairly quiet as it is but is an issue that will be dealt with at some point in a future leg of this project...This furnace will be replaced at some point but it is not in the budget right now

Any studio wiring will travel through the basement when necessary..There is no control room in this space btw.

Soundman..the floor right now is original maple flooring over 3/4 inch subfloor, that will not change.

Right now for the major structures im working on and some updating of the bathroom and kitchen im gonna be in about 20K american money.

[Krackle]

Had an architect friend over the other day and he said he liked the visual of the two sections both slightly sloping up towards the east..so, might just leave the slopes, i like em too..

im guessing it won't create any foreseeable issues vs dead horizontal..treatment afterwards of course...We had a good system for the structure already so wont have to fudge anything..

one question for this morning's work:

The legacy plaster walls go floor to ceiling, plaster is well over 1 inch thick in most areas..these old walls meet the ceiling (drywall on floor joists for floor above) in a normal way..structurally and then plaster meeting drywall-taped and mudded.

My plan is to make cuts in the old plaster walls (circular saw and concrete blade-dust removal in place) just below where the new ceiling line is, neatly. I dont think i want the old plaster walls walls joining the ceiling im about to cover up?

Once the ceiling is built and skinned and capping the old walls..I'll start planning the decoupled shell walls inside the room..room inside the room..

hope that's all clear..starting with a basic room with walls and ceilings covered in plaster and drywall..adding a second, lower ceiling..but snipping the old walls so they meet the new ceiling instead of going all the way up to the old ceiling>which is the current state..

[AVare]

Once the ceiling is built and skinned and capping the old walls..I'll start planning the decoupled shell walls inside the room..room inside the room.

What is the resonance frequency of the ceiling system? If it is not at or near 47 Hz, why? What is the resonant frequency or frequencies for the walls?

Andre

[Krackle]

I'm not sure how to calculate any of this, Avare.

Existing ceiling or new ceiling?

Old plaster walls or new shell wall?

[AVare]

I'm not sure how to calculate any of this, Avare.

Existing ceiling or new ceiling?

Old plaster walls or new shell wall?

Use the MSM (AKA MAM) equation.

It is for the wall and ceiling 2 leaf systems, not the individual leafs.

Andre

[Krackle]

Searched for those (google) and couldn't find anything relating to those acronyms.

Are they in a sticky somewhere?

[AVare]

Searched for those (google) and couldn't find anything relating to those acronyms.

Are they in a sticky somewhere?

I do not understand what is going on. I did a test on Goggle with the "MSM frequency calculator" The first hits were for here!

Study Bradley in herehttp://johnlsayers.com/phpBB2/viewtopic.php?f=3&t=21894. There is upposedly more than what you need right now, but those walls are coming fast!

Andre

[Soundman2020]

I'm not sure how to calculate any of this, Avare.

Then you have a problem! Not trying to smart-ass here, just pointing out reality: You are about to build something you don't understand, and don't know hot to calculate. I'm not sure you even understand the implications of knowing what that MSM resonant frequency is: why it is important, and what you should do about it if yours is wrong. People here are giving you very good advice, for free, and you don't seem to be interested in looking at it: it seems you just want to move ahead with the build, but in general it's not a good idea to start building a studio until you have it fully planned. Take a look at Andre's signature block: I used to think it was an exaggeration when I first saw it, many years ago, but now I think it might actually be understated: I suspect the best ratio might be higher than 90:10... You might not realize it yet, but Andre is one of the best acousticians in the business, and he's giving you really excellent consulting advice for free. If you had hired him to design your place, the small amount of advice he's given you so far would have saved you thousands of dollars in construction costs, and it would have cost you a few hundred dollars to get that advice. But you got it for free! From one of the best in the business. You really should take a bit more notice of what he is telling you. Unlike me, he likes to be brief and to the point, but every single point he makes is critically important... Me? I just tend to waffle on and on forever, saying the same thing he said, in ten times as many words....

- Stuart -