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Hello,
I post exceptionally because drummer from France I can hardly find advice for my sound insulation project. I intend to order the products below and do myself the work with a friend specializing in partitions. Already well advanced in my head and on paper, I have only 1 question. If you had a contact who knows these topics well it would be great to be able to ask him his opinion. I take any last advice to realize well this studio "box in the box", ground, walls, and ceiling based on mass-spring- mass. Here is the plan and the details of my play and my question, or rather seeking advice, is on the balance of these walls:

Does the ratio of rockwool vs masses seem balanced? (Or if it would take more mass or on the contrary more rockwool?)

Note that this apartment is in the basement, no neighbors below or on the sides (left, right, front, behind), but above only and the ceiling height is 2.15 m.

I will use rockwool 70 kg/m3, and that the heavy mass makes about 5 kg/m2 for 2.5mm, or in 5 mm 7.5 kg/m3, or in 10 mm 10kg/m3.

ba13 and ba18 are plates of plaster 13 and 18 cm thick.

(The details concerning the electticity, the light, are regulated, so I do not approach them)

- Floor : Because of this lack of ceiling height, but also because I have no neighbors below, I intend to do the ground quite simply: 5 mm (minimum) heavy mass on the entire surface floor + floating floor 14 mm = 1.9 cm. I know that my floor should not touch the walls (separation of a few mm) to separate, do not create bridges phonic.

- Wall A (where there is the door 82 mm/-50dB): ba 13 mm + heavy mass 20 mm (glued to ba13) + wood frame (100 mm depth) + in the frame rockwool 100 mm + empty air 10 mm + ba 18 mm + heavy mass 20 mm + acoustic Ba 13 mm = 19.4 cm (thicker wall because it looks on the rest of the apartment, and not on the load-bearing wall).

- Wall B (on very thick load-bearing wall): wood frame 100 mm + in the rock wool frame 100 mm + Ba 18 mm + heavy mass 10 mm + ba 13 mm acoustic = 14.1 cm.

- Wall C: Ba 13 mm + heavy mass 10 mm (glued to ba 13) + wood frame 70 mm + in the rockwool frame 70 mm + ba 18 mm + heavy mass 10 mm + ba 13 mm = 13.4 cm.

- Wall D (on thick bearing wall which gives on cellars): As wall B.

- Ceiling: Glue heavy weight to the original ceiling. But before fixing the acoustics shroud (sustainers) in which we enter the lines (rods) to create a frame to put over the rock wool, and screw to the frame of the heavy mass previously glued to the ba13. Total: 20 or 22 cm.

(Note that some rubber bands will be used mainly on the ground so that the wood frame does not touch the ground, so to separate, do not create sound bridges between the tiles and the walls. They will be useful in general construction everywhere necessary if it will break any bridge possible phonic between two "hard" materials.)

Best regards.

(Here are the products used) :

Then one of the following 3 heavy masses (must re compare, there are the data sheets) :

Comments

kmetal Sun, 05/05/2019 - 16:01

Im not sure if your using the rockwool to treat the sound of the inside of the room, or if your implying it has a significant effect on the isolation.

You dont need to float a floor. At ground level the existing slab is your best source of isolation.

For walls and ceiling, you either use a new set of wood frames, or RISC-1 clips/hat channel, to create your room-in-room. These are the only two methods that will reliably help isolate the SPLs drums generate.

For mass, standard 5/8" drywall, with optional green glue, are what to use.

Standard fluffy insulation is best for wall cavities.

Rockwool is useful for bass trapping. Rigid fiberglass/rockwool useful for acoustic absorber panels. How much depends on the size of the room. General figures are 20-30% of the surfaces covered with mid-high absorbers, and 40-60% treated with bass trapping.

When talking things like floating floors which dont work except for highly specific and expensive cases, or mass loaded vynal sheets, which are difficult to install and much more expensive than standard wall sheathing, the waters become murky and expensive.

The methods described in Rod Gervias's book "home studio, build it like the pros", is tried and true, cost effective, and widely used in the best of the best commercial studios, home studios, and everything in between. Ive used his methods in several large and small studio builds.

jerem1 Tue, 05/07/2019 - 05:32

Thank you very much kmetal and sorry for the late.

Thank you for that information for the floor. Indeed I was not sure that for the floor it was so easy. I am happy to know that i don't need to build a structure. I heard as you that an american sound engineer, Jonn Sayers, said (if i am not wrong), that in apartment is in the basement, with no neighbors below, it's not mandatory to build a floor with the system mass-spring- mass (like the walls). But is it sure for you ? So if i understand i juste need to put my parquet, floating floor on my actual floor tile ? And no heavy mass like a minimum 2.5 mm in between ?

Yes or the Rockwool i heard also that it is not so much for insulation but for the low frequencies. But i don't know if 70mm rockwool and 100mm for Wall A is enough for my 10m2 room playing drum. In general i don't know if the walls i described seems ok for a 10m2 drum room. But you said that the rockwool need to be around 40-60% for treating bass trapping, and thank you also for that information, it seems that my walls (if i am not wrong) have indeed 40 or 50% of rockwool.

Yes the would be a wood frame or metal as you said. I heard wood can be a little bit better for acoustic than metal but maybe it's not significant.

Thanks a lot.

kmetal Tue, 05/07/2019 - 14:36

jerem1, post: 460938, member: 51587 wrote: I heard as you that an american sound engineer, Jonn Sayers, said (if i am not wrong), that in apartment is in the basement, with no neighbors below, it's not mandatory to build a floor with the system mass-spring- mass (like the walls). But is it sure for you ? So if i understand i juste need to put my parquet, floating floor on my actual floor tile ? And no heavy mass like a minimum 2.5 mm in between ?

John Sayers is a well regarded acoustician and audio engineer from Australia. For your flooring, there is no need to do anything as far as adding mass. Assuming proper humidity, install your floor covering using standard methods directly on the exist floor. This will probably involve some sort of underlayment in between the tile flooring and new floor covering.

jerem1, post: 460938, member: 51587 wrote: Yes the would be a wood frame or metal as you said. I heard wood can be a little bit better for acoustic than metal but maybe it's not significant.

Wood offers the significant advantage if being able to hold more layers of drywall, and support the weight of a ceiling. It also blocks low frequencies better. Steel has an advantage of being fire proof, and wont twist in high moisture areas.

kmetal Tue, 05/07/2019 - 16:20

For placement of rockwool-

Assuming this room is not used for mixing, just tracking, heres what id generally do.

Cover most of the ceiling with absorption, since low ceiling's reflections are generally not useful.

Id cover the walls behind and to the side of the drum kit, almost completely.

Once you get into the open area of the room id distribute the absorbers more sparsely, treating spots here and there. The goal here being to help tame unruly ambience, flutter, and pings. We want to eliminate interfereing reflections from getting back into the mics near the kit.

This orientation of your absorption, allows for nice tight, punchy, and clear closer micing of the kit, and more open and ambient sound for the more distant mics.

jerem1 Wed, 05/08/2019 - 04:19

Thank you very much for those details and so sorry to ask.

- I noticed that difference between metal and wood. There is not so much humidity so i will go for wood if possible (i will see with the guy that help me what he can do do, prefer) both are ok for me.

- For the floor that was i wanted to do, putting some heavy mass (5kg/m3) in between the actual floor tile and the floating floor. I am just hesitant putting a thickness of 2.5mm, 5mm, or 10mm heavy mass ?

- Ceiling : Yes the rockwool will be the main thing. But insulation, soundproofing is very important for the ceiling because the only neighbors are at the floor upstairs, and i know that for insulation, soundproofing, mass is also very important. So i wanted to do : Glued some heavy mass to the original ceiling, and before fixing rubber/metal acoustic sustainers in which we enter the lines, rods, to create a frame to put all over the rockwool, and finally closing with screwing to the frame the ba13 previously glued to heavy mass. Total: 20 or 22 cm. Exactely : 10mm heavy mass glued on the actual roof + 170 mm rockwool + 10mm heavy mass glued to ba 13mm = 20.3 cm. Do you think it's ok for my drums (soundproofing, acoustic insulation) and there is enough rockwool as you mentioned ? Note that the actual ceiling between me and the neighbors is around 20 cm plaster i think, so i need to isolate well.

- And yes, after insulation, i will do an acoustic treatment inside the room (bass traps, foam...).

Best regards.

kmetal Wed, 05/08/2019 - 07:27

jerem1, post: 460948, member: 51587 wrote: For the floor that was i wanted to do, putting some heavy mass (5kg/m3) in between the actual floor tile and the floating floor. I am just hesitant putting a thickness of 2.5mm, 5mm, or 10mm heavy mass ?

There is no need for more mass on the floor. The concrete slab has tile on it which is heavy, and is insulated by earth (dirt) this is about as good as it gets from an isolation perspective. So your floor is the strongest link in the chain of your build. The walls or ceiling wont meet or exceed the isolation value of the floor.

What you may want to do is use some self leveling concrete, a skimcoat, just to fill in the gaps on the tile/grout, to have a smooth surface to apply the new floor covering to. Id only do this if it was deemed necessary by the floor installer.

jerem1, post: 460948, member: 51587 wrote: Ceiling : Yes the rockwool will be the main thing. But insulation, soundproofing is very important for the ceiling because the only neighbors are at the floor upstairs, and i know that for insulation, soundproofing, mass is also very important. So i wanted to do : Glued some heavy mass to the original ceiling, and before fixing rubber/metal acoustic sustainers in which we enter the lines, rods, to create a frame to put all over the rockwool, and finally closing with screwing to the frame the ba13 previously glued to heavy mass. Total: 20 or 22 cm. Exactely : 10mm heavy mass glued on the actual roof + 170 mm rockwool + 10mm heavy mass glued to ba 13mm = 20.3 cm. Do you think it's ok for my drums (soundproofing, acoustic insulation) and there is enough rockwool as you mentioned ? Note that the actual ceiling between me and the neighbors is around 20 cm plaster i think, so i need to isolate well.

You likely need to remove the existing ceiling drywall, and apply drywall inbetween the framing studs. You can re-use the drywall you remove and pack it in the bays.

This is outlined in build it like the pros, the book you should have ordered by now.

If you leave the drywall as is you create whats known as a "3 leaf" system which makes isolation worse. You want Room in a room. A three leaf system is like a room in a room in a room.

Your proposed setup would have three leafs- 1. Flooring above 2. Drywall on ceiling 3. New ceiling on channel.

When you remove the drywall on the ceiling and pack it in tbe bays, attached to the upstairs flooring, you eliminate one of the leafs.

Ditto for the walls.

For drums isolation id be considering a minimum of 3 layers of mass in the bays, 3 layers on the new isolation framing. Adding green glue in the isolation layers will be very useful.

Even with all that your still looking at sound bleeding upstairs and it depends how pateint your neighbors are. If there watching tv then the noise you make probably wont bug them much. If they're quietly reading then it might.

Since three layers of drywall is the max the RISC-1 clips can hold, and those clips hold the most of any clip/channel system i know, three layers and glue is your limit. After that, you would need a new wood framed ceiling resting in your new walls, which would hold significantly more layers.

They do have heavy duty clip/hanger systems, but they are significantly expensive compared to a new wood framed system.

I urge you to take a step back, get the book, and re-evaluate your plan. You want to make your mistakes on paper where it doesnt effect your bank account.

Youve got to test your drums with a DB meter, and see what the readings are 1 meter from the kit, in your bedroom, outside the studio (outdoors), and upstairs if your neighbors will let.

The readings from your bedroom will be a good estimate of upstairs readings.

A jazz drummer would play in the high 90s DB, where rock/pop/metal 110db+.

Given the time and expense of your project, and the fact that it involves neighbors which could be a different set of folks in a year or two, its absolutely critical your plan facilitates your isolation requirements.

I appreciate the amount of work youve done so far, it shows you have the potential to get it right, but youve got to re-evaluate and alter your plan if you want it to work.

Particularly the ceiling.

For walls you want- studio wall and foundation wall only. This means if your careful, you can re-use the existing framing for your studio walls, and the drywall for adding mass to the ceiling bays.

There is a science to studio design, and an art to project planning and budgeting, which have to have synergy, or you end up with an expensive mistake, or unfinished money pit.

Im glad to help here, but its beyond the scope of this forum to recite the priniciples and designs in the book(s). The best thing is to use it as a common reference, and fill in here whats unclear to you, or unique to your case.

I dont have any financial benefit from the book. I bought my copy in 2006. It led me down a decade of research and studio builds.

jerem1 Wed, 05/08/2019 - 09:55

Thank you for the book i found it (it's not easy for me in english even with google translator, but i will do my best to read it before doing anything).

The neighbors are very nice, it's an office (nobody en the evening and week end) and some noise at the day because they move, they work. But i want to do my best for them and me.

Here is a video if it can help of the room but it's in french if it helps : https://streamable.com/klfdk

- For the floor i have no problem of understanding, i understand perfectly that i don't need to put heavy mass before the floating floor and i wanted to put 5 mm or 10mm but now i'm reassured and i will also save space, but to tell you the truth i am still hesitant, tempted to put only a very little 2.5mm or 3mm heavy pas, or nothing to follow exactly your opinion. I don't think ot can be a problem to put that very thin layer of heavy mass. Hope it's not a big problem, because i don't why, maybe in further to have a flat and just a little dumping surface.

-Also thank you for the Risk-1 i will see with the guy help me, but to separate the wood frame from the ba13 to avoid creating sound bridges i thought more rise use simply that product : https://www.amazon.fr/dp/B00MGCRUI0/?tag=r06fa-20

But the Risk-1 seems very good, i will see for it (i'm quite sure there isn't it in France, i will see, or command it and the guy help me understand it).

- For the ceiling I am sorry but something is not clear for me or for you but i hope i expressed myself enough well to be understood, or maybe i can't understand everything.

In what i described it's only a "2 leaf" system because i just glue to the actual roof some heavy mass (so we have here the first mass) after it's 170 mm spring, and after we close with the last mass (heavy mass glued to ba13). So we have mass-spring-mass system with 2 leaf of mass (1 at the beginning, one at the end). Except if you consider the spring as a leaf but for me it is just the spring, necessary for the mass-spring-mass system and the drying wall where there is the rockwool is not called a leaf. A leaf is in my opinion one the masse. So i heard it's not good indeed to have 3 layers of mass but in my plan there is only 2 layer of mass : the actual ceiling just glued to a 5mm layer of heavy mass, after there is the spring of rockwool, and to finish the second layer of mass just constituted by some mass glued to ba13.

And note that for me the flooring above, the flooring of my neighbors is some parquet. So the parquet+the 20cm plaster ceiling between us and i + the heavy mass i glued to this ceiling constitued a single peace of mass in the systeme mass-spring-mass.

I did not understood this : " You likely need to remove the existing ceiling drywall, and apply drywall in between the framing studs. You can re-use the drywall you remove and pack it in the bays" and this "When you remove the drywall on the ceiling and pack it in tbe bays, attached to the upstairs flooring, you eliminate one of the leafs."

I'm also not sure to understand when you said : "For drums isolation id be considering a minimum of 3 layers of mass in the bays, 3 layers on the new isolation framing." You mean that for the heavy mass on my walls and ceiling, instead of having 10mm of heavy mass consisting by 2 layers of 5mm heavy mass, it's better to have mutiple layers of 2.5 or 3 mm heavy mass ?

If you can do simply draw on a paper there is no better way in think to understand. I am so sorry to ask but the roof seems the main "problem" and i noted that you did not said anything about my walls simulation, so maybe it's sound ok for you for that walls.

- To finish I understood all the rest of you message.

Again i am so sorry to disturb with that project and thank you very much kmetal for your helps and advice, i have at least advanced on some points.

jerem1 Wed, 05/08/2019 - 10:01

Thank you for the book i found it (it's not easy for me in english even with google translator, but i will do my best to read it before doing anything).

The neighbors are very nice, it's an office (nobody en the evening and week end) and some noise at the day because they move, they work. But i want to do my best for them and me.

Here is a video if it can help of the room but it's in french if it helps : https://streamable.com/klfdk

- For the floor i have no problem of understanding, i understand perfectly that i don't need to put heavy mass before the floating floor and i wanted to put 5 mm or 10mm but now i'm reassured and i will also save space, but to tell you the truth i am still hesitant, tempted to put only a very little 2.5mm or 3mm heavy pas, or nothing to follow exactly your opinion. I don't think it can be a problem to put that very thin layer of heavy mass. Hope it's not a big problem, because i don't why, maybe in further to have a flat and just a little dumping surface.

- Also thank you for the Risk-1 i will see with the guy help me, but to separate the wood frame from the ba13 to avoid creating sound bridges i thought more rise use simply that product : https://www.amazon.fr/dp/B00MGCRUI0/?tag=r06fa-20

But the Risk-1 seems very good, i will see for it (i'm quite sure there isn't it in France, i will see, or command it and the guy help me understand it).

- For the roof it's a little bit more complicated because for me in what i described it's only a "2 leaf" system because i just glue to the actual roof some heavy mass (so we have here the first mass) after it's 170 mm spring, and after we close with the last mass (heavy mass glued to ba13). So we have mass-spring-mass system with 2 leaf of mass (1 at the beginning, one at the end). Except if you consider the spring as a leaf but for me it is just the spring, necessary for the mass-spring-mass system and the drying wall where there is the rockwool is not called a leaf. A leaf is in my opinion one the masse. So i heard it's not good indeed to have 3 layers of mass but in my plan there is only 2 layer of mass : the actual ceiling just glued to a 5mm layer of heavy mass, after there is the spring of rockwool, and to finish the second layer of mass just constituted by some mass glued to ba13.

And note that for me the flooring above, the flooring of my neighbors is some parquet. So the parquet+the 20cm plaster ceiling between us and i + the heavy mass i glued to this ceiling constitute a single peace of mass in the system mass-spring-mass.

I think indeed if you read closely again my plan for the ceiling and what i just said above in that post, you will see that my ceiling plan is really more close of that system "STC 63" in that image than anything else : https://recording.org/attachments/imgext-gif.18991/

And also like that double leaf here : https://recording.org/attachments/images-jpeg.18992/

Il will do also in few minutes a draw to describe the ceiling ( i thought it was described well).

I did not understood this : " You likely need to remove the existing ceiling drywall, and apply drywall in between the framing studs. You can re-use the drywall you remove and pack it in the bays" and this "When you remove the drywall on the ceiling and pack it in the bays, attached to the upstairs flooring, you eliminate one of the leafs."

I'm also not sure to understand when you said : "For drums isolation id be considering a minimum of 3 layers of mass in the bays, 3 layers on the new isolation framing." You mean that for the heavy mass on my walls and ceiling, instead of having 10mm of heavy mass consisting by 2 layers of 5mm heavy mass, it's better to have multiple layers of 2.5 or 3 mm heavy mass ?

If you can do simply draw on a paper there is no better way in think to understand. I am so sorry to ask but the roof seems the main "problem" and i noted that you did not said anything about my walls simulation, so maybe it's sound ok for you for that walls.

- To finish I understood all the rest of you message.

Again i am so sorry to disturb with that project and thank you for your help and advice, i have at least advanced on some points.

jerem1 Wed, 05/08/2019 - 11:10

Here are the draws.

I think i understood why you saif 3 leaf, because on all the walls there is a leaf of ba18 plaster and ba13 plaster. But it is not 2 leaf, because there not spring in between. For me and i heard that exactly the "sandwich" i need to do to create mass, ba18 + heavy mass + ba13 are one mass, glued each one to another like one piece.

And it's even more revealing for the ceiling because there is no at all ba18.

http://zupimages.net/viewer.php?id=19/19/p65d.jpg

http://zupimages.net/viewer.php?id=19/19/tyxw.jpg

http://zupimages.net/viewer.php?id=19/19/fdp5.jpg

kmetal Thu, 05/09/2019 - 08:15

jerem1, post: 460953, member: 51587 wrote: For the floor i have no problem of understanding, i understand perfectly that i don't need to put heavy mass before the floating floor and i wanted to put 5 mm or 10mm but now i'm reassured and i will also save space, but to tell you the truth i am still hesitant, tempted to put only a very little 2.5mm or 3mm heavy pas, or nothing to follow exactly your opinion. I don't think ot can be a problem to put that very thin layer of heavy mass. Hope it's not a big problem, because i don't why, maybe in further to have a flat and just a little dumping surface.

Glad to assist you. Theres no reason based on physics to do this. Your floor is the most massive part of your studio already. Mass is pounds per sqaure foot over here, im guessing kilograms per meter over there?

Either way your floor mass exceeds what your planning on your walls and ceiling by quite a bit.

Avatar/The Powerstation, a famous world class, New York City, USA, studio built there rooms directly on a slab on earth (dirt), just like your studio. They added no mass between the slab and the wood floor covering.

Do as you want but know theres no improvement to be made by adding mass to the floor. Theres no acoustics pro, or physicist who would tell you otherwise.

jerem1, post: 460953, member: 51587 wrote: I'm also not sure to understand when you said : "For drums isolation id be considering a minimum of 3 layers of mass in the bays, 3 layers on the new isolation framing." You mean that for the heavy mass on my walls and ceiling, instead of having 10mm of heavy mass consisting by 2 layers of 5mm heavy mass, it's better to have mutiple layers of 2.5 or 3 mm heavy mass ?

Mass is mass so from that perpective 10mm, 2x5mm, and 4x2.5mm is equal assuming it weighs the same.

The advantage to multiple layers is the ability to add Green Glue in between the layers to increase isolation.

For "in between the bays" -

When you remove the drywall on the ceiling, youll expose the ceiling framing joists. The space between those joists is reffered to as "a bay". This is where you'll commonly find insulation. What you do is remove the insulation, and fasten drywall strips (mass) to the studio side of whats the flooring upstairs. You add drywall to the underside of the upstaris flooring.

There are great illustrations in the book. Ill see if i can find a picture in the meantime.

Why your ceiling is 3 leafs.

Leaf 1- upstairs flooring

Leaf 2- existing drywall downstairs ceiling

Leaf 3- your new drywall attach to the clips.

So its mass-air-mass-spring-mass.

When you remove the existing drywall on the ceiling you then have a proper 2 leaf system with the clips and new drywall installed.

As far as that isolation tape, ive never used it. Its not required when using risc-1.

jerem1 Thu, 05/09/2019 - 10:42

Thank you again very much.

For the floor, i think, and read you again, and you convinced me more. But i understand more why i wanted that thin layer of heavy mass : In my mind the problem is not the mass on the floor, you're totally right, there is earth under, and even more materials (it's a classic building in Paris) under that the floor tile. So the problem for sure you're right there is no problem of mass, but maybe a problem of "acoustic", "reflections" with the floor tile himself ? Indeed for me, in my mind, it's a tough and rough material (and i will be just under a thin 1.4mm parquet), so for me, a though and rough material like squares of floor tile are not a good thing for acoustic, not isolation, but quality sound acoustic, reflections, "treatment", etc.... That's why i wanted to put something more "elastic" in between. So in a pure question of mass i understand totally what you said and you convinced me, but if we think more about "treatment", sound reflection, acoustics qualities, i thought that squares of floor tiles are bad, baddest as heavy mass. So i was not clear in the purpose of that thin layer of heavy mass on the ground. But if you understand me and tell me again that i am wrong (and why) on that point, so not isolation, but acoustic but acoustic qualities, reflection, etc... i will go you way, i will put the wood floating floor directly on the floor tile. Sorry to ask, talk, but i just had that thought, i understood more precisely why i wanted that layer of mass.

For the multiple layers i totally understood what you said. But are you sure the green glue has a significant action on isolation ? I did not knew that. I thought it was just a glue but a little bit better than other for acoustic and that was really not significant in the total balance sheet of such a structure. And also i wanted more going on layers of 5.4 mm (it's the maximum in France) than little layers of 2.5 because i thought that it gonna be easier to glue one to each other pieces of 5.4 mm than pieces of 2.5 in further to maintain, keep up the structure. But if you tell me that that green glue is so important that it's better to put thinner layers that thicker, i will go for it (but it still a bigger problem to glue every thing, and more glue used also).

Now i understand what ares bays and about removing drywall to make it better with filling the bays with mass, add drywall in bays, and after rockwool. It's a great idea but i can't do this legally, i can't touch that ceiling because it's an apartment in a building in co-ownership (the only thing that separates me from the neighbors above, is that 20cm layer of plaster and their floating floor). The idea is perfect and i
am really tempted to do it but it's more work and especially risky works, and not legal (i can do it technically and the week end nobody see it and i'am sure nobody will see it (if i do it the week-end) and even it's better for everybody. Maybe i can ask but it's very complicated and long if i ask the co-ownership. I will widely prefergoing on the idea of fixing first of all heavy mass on that ceiling, going as i described but if there is a better solution (without touching that ceiling) i'll take it, go for it.

Again that's what i see for the ceiling : Glued some heavy mass to the original ceiling, and before fixing rubber/metal acoustic sustainers in which we enter the lines, rods, to create a frame to put all over the rockwool, and finally closing with screwing to the frame the ba13 previously glued to heavy mass. Total: 20 or 22 cm. Exactely : 10mm heavy mass glued on the actual roof + 170 mm rockwool + 10mm heavy mass glued to ba 13mm = 20.3 cm.

So for the Risk-1 i can't really use it because of what i said i have no access at the joists (because of the co-ownership settlement). I will go the classic way : sustainers in which we enter the lines, rods, to create a frame to put all over the rockwool, and finally closing with screwing, clipping to the frame the ba13 previously glued to heavy mass.

And i think understood also why you say it'a 3 leaf : neighbors parquet (basically) is mass ; joists/empty bays (spring) ; actual plaster + my glued heavy mass (mass) ; my rockwoolspring) ; and i close (like one piece, leaf) with the ba18/heavy mass/ba13 sandwich (mass). And you said : leaf 1 upstairs flooring ; Leaf 2- existing drywall downstairs ceiling (plaster) ; and my ba13/heavymass/ba 18 "sandwich piece" attach to the clips. So yes it's 3 leaf if regard things like this.

But for me (i hope i a not wrong) the leaf 1 upstairs flooring and Leaf 2- existing drywall downstairs ceiling (plaster) are just one leaf. I say this for many reasons : the floor of my neighbors is very poor (it's Paris, old building of the end of the 19 century, 1880 exactly) i hear them very well walking on the parquet. The ceiling of the neighbors is consisting parquet with under like 5 cm plates of wood, a little air indeed, and directly they full the bays with plaster. So basically you have 6 or 7 cm wood (parquet + plates of wood under the parquet, 5 cm of mix air and plaster (it's doing like waves of plaster the electrician told me) and to finish 10 cm of full plaster. But as we see the air is not very important and above there is only 5 or 6 cm of wood plates, parquet, that's why i am not sure we can talk of layers of "mass" for the wood there is above that thin layer of air. The plaster (with the mass i'm gonna put) is in my mind the real, the main layer of "mass", and the little air and wood above are to thin to be consider as something significant in the structure. Isn't it ?

I just had the information by the electrician. I thought there was no air, that everything was full of plaster. So indeed it like 2 leaf and with my my ba13/heavymass/ba 18 "sandwich piece" attach to the clips it's gonna be 3 leaf. :cry:

I don't know what to do. I asked the electrician to send me a draw of the ceiling, because he saw it entirely, because the last owner has dug illegally to put some lights in the bays) and the electrician had to fill it.

I'll send you a draw of the entire ceiling as soon as possible. I think, i wait for the draw of the electrician, it's very thin layer of air, so for me all that ceiling can be a little bit like one piece, one leaf.

We are close to found a solution for that ceiling, the last thing to see (it's seems i guess quite clear for floor and the walls isn't it ?).

thanks very much again.

jerem1 Fri, 05/10/2019 - 03:15

Hi,

- For he floor under the floor tile it's kind of bitumen, so it is not earth. So the acoustic qualities (not the acoustic isolation) are very bad. That's why as i said i wanted to put heavy mass.

- For the ceiling i confirm that i can't do anything because i can destroy the ceiling for the co-owner settlement and it's complicated technically.

Here is a draw of the ceiling.

We can see that there 25 cm in all, comprising 3cm of parquet ; the joists ; and all to the joists it's full of plaster ; but under the hollow those waves of plaster there is 8 cm plaster ; and air above.

http://zupimages.net/viewer.php?id=19/19/zeu5.jpg

As we see for me the 3cm parquet of my neighbors can't be view as a leaf, a "mass", so for me can be taken as "mass", only the waves (of 25 or 8 cm plaster depend on where on the wave + the heavy mass i'm gonna glue). So that celing + the ceiling i'm gonna clip to my structure, shroud, is the second leaf of mass.

Thanks

kmetal Sat, 05/11/2019 - 08:00

Green Glue- check the specs. If i recall correctly, it equals a layer of 5/8" (15.8mm).

Drywall thickness- we use generally 5/8" (15.8mm) layers of sheathing here for studio purposes. 5.4mm (1/4") drywall is very, very thin. A typical studio uses 2-3 layers of 15.8mm, so your looking at 6-9x layers of 5.4mm to meet this criteria.

I would contact Green Glue, explain your case, and ask them if GG is an effective solution.

I also reccomend you contact the manufacturer/seller of the isolation clips, explain your case, and see what solution they have.

Yes, the flooring counts as a leaf. Its not just mass to consider, but the fact the the studs cannot flex and deflect as much with somthing affixed to both sides. Flex is an import part of how sound travels. Similar to a car suspension. Too much flex, or hardly any flex, and if wont be effective.

Since there is nothing that can be done to change the leaf situation, its got to be lived with.

Any mass that you have should be located on the new ceiling/clips, up to the maximum allowable mass. The reason, is the mass is much more effective in the isolation assembly, than it would be on the existing assembly. Adding mass to the existing assembly has much more Diminishing Returns.

Im assuming your leaving an airspace between the existing drywall and the new rockwool/mass layers correct?

In the book, Rod has a drawing of what your proposing- a suspended insolation ceiling. There are purpose built hangers made specifically for this.

Depending on your space and building codes, you may want to consider a new set of wood framed walls and a wooden ceiling frame resting on the walls, below the existing drywall/ceiling.

This design achieves the maximum amount of isolation and is cheaper than clips (at least here in Boston). Since we have the reality of the 3 leaf system, its best to make the best type acheiveable.

There is also a method that uses lines/hangers to hold wood framing.

One thing to keep in mind is that the assembly as a whole is strong as its weakest link. So you want your walls and ceiling to have equal isolation, even if the design/methods are different, like for example, risc 1 for walls, hangers for ceiling.

What you dont want is to waste resources making the ceiling better than the walls, since the sound will always take the path of least resistance.

Also worth noting. The clips/hangers will not block the 'impact noise' from people walking around upstairs. The foot noise, and creaks from the joists flexing will only be solved be a ceiling that physically isnt touching the existing one in any way. (Physically Decoupled).

I encourage you to look at what you can do, and make sure its worth it, since the conditions are less than ideal. Without a doubt contact the manufacturer and make sure your situation would even benefit from their system.

Ive seen the data sheet for risc 1, where they 'short circuit' the system by using screw that are too long. They penetrate the channel and go into the existing celing assembly. After 5-10 screws the entire clip system was rendered void, and was no better than the existing assembly itself.

My point is you may find your conditions make it so the best bet is to either add mass to the existing structure, or use electronic drums, or get a pre made booth like a wisper room, or do nothing and rent a practice space of different apartnent.

Floor- so its tile and bitumen, whats undeneath that? Wood? Concrete? Earth? Something else?

Based on the graphics with the STC ratings on it, seems you having to leave the existing drywall cost you about 10db in isolation.

Thats a speculation on my part, based on the graph. I cant reccomend enough you contact the manufacturer and verify for your specific case. I would also reccomend you find a local acoustician to help you out. He will be experienced in standard construction methods in your area, the appropriate work arounds, and speak french.

Im happy to help however i can mon ami, but ive never had to build a room with the existing conditions yours imposes, therefore cannot guarantee how effective any given solution would be.

cyrano Sun, 05/12/2019 - 04:12

You really should do some acoustic measurements...

The floor, fi, is probably resting on the foundation, at the edges. Meaning, that there's air under the floor. That might, or might not, form a resonant cave. Not that I think the floor will be a problem, but you never know. The problem with floors is that they react very differently when the room is empty.

Insulation is harder to do right than absorption. Measuring what you're up against, will allow to use less materials. And as these are costly, it saves you a lot of money.

The last small studio I did, had offers ranging from 7.500 to 18.000 € for treatment of one room. Some of these companies didn't even visit the room. In the end, we spent almost a 1.000 € on measurements and far less for materials. The owner of the studio built his own absorption panels, with the help of a friend who's a carpenter. When finished, there was one minor resonance left, around 275 Hz, IIRC. That turned out to be the table supporting the mixer. That table was replaced with one that had a perforated top. A bit of sliding the monitors left/right did the rest.

jerem1 Sun, 05/12/2019 - 06:41

Thank you again for your help.

- To Cyrano : For the floor before the foundation there is a lot of mass before the foundation, there is i guess mass between the foundation and my room. So i 'm really not worried for the floor because for sure there is mass before foundations, and also simply because even if i wanted do something better for the floor, i can't, i have no choice, i can't do any thick structure because of a lack of ceiling height. Isolate the ceiling will be more important.

- Yes (it's a good idea), I'm going to contact the company that sells the Risk-1 to ask them how to create my ceiling other than with sustainers and hangers, suspended ceiling, if they see another solution.

- For the green glue I will see. I'm not sure it will be better to put thinner layers of mass than thicker layers in further to put more Green Glue. I red the specification of green glue and it's more for cracks and gaps. But i will follow you advice by putting more and thinner layers of heavy mass than thickers in further to have more green glue.

- I think that the thickness of my walls is correct and can not do much more because I will lose too much space. Maybe i can try to make walls a little thicker because you seem to say they are too thin. I did not understood that : "Drywall thickness- we use generally 5/8" (15.8mm) layers of sheathing here for studio purposes. 5.4mm (1/4") drywall is very, very thin. A typical studio uses 2-3 layers of 15.8mm, so your looking at 6-9x layers of 5.4mm to meet this criteria." Simply, in all how much do the walls of your studios in mm or cm or inch ?
More precisely, you saw that I have two thick bearing walls, then two walls completely to create, and I gave precise thickness and the composition of my walls, what thickness did you usually see ? The Wall A is 20cm and for this studio ? Wall A is 20 cm and the others around 14 (because there next to a bearing wall).

- "Im assuming your leaving an airspace between the existing drywall and the new rockwool/mass layers correct?". The spring, the air is assuming by the rockwool it's the air, the spring in the "mass-spring-mass" system). So don't need airspace in the walls because the rockwool il a soft material that assuming the role of air.

- For the ceiling here is some picture of what i am gonna do simply, except that i am gonna glue to the original ceiling some heavy mass (because even it' the only thing i see to reinforce the original ceiling before building my suspended ceiling) and closing the ceiling with a "sandwich" of ba18/heavy mass/ba13 :

https://fr.audiofan…

But if you can do a draw of what you're proposing for the ceiling and maybe for the walls it will be really much easier for me to understand. For me simply i build the walls as i said and after a make the suspended ceiling as i described above with links, pictures.

You seem indeed to have a different idea for example when you said : "you may want to consider a new set of wood framed walls and a wooden ceiling frame resting on the walls, below the existing drywall/ceiling.". But it's difficult to understand without a draw.

- To Cyrano : For the point about the acoustic measurements, i wanted to do some for the the acoustic treatment and not for the isolation, for building the room. Precisely what kind of measurements can do an acoustician to help me before making the studio (i think it can help after for treatment, : position of bass traps, etc...) but for constructing the walls and the ceiling it's almost always the sames system and materials : mass-spring-mass : plaster/heavy mass - rockwool - heavy mass/plaster.

- I think we made the point about the floor, and just maybe some draws about the walls and the ceiling because you seem to have a different idea of what i can do for the walls and the ceiling, and will be appreciate a lot, and little bit easier to understand if you can make a draw.

I'm gonna read Rod's book right now.

Thank you again.

KurtFoster Sun, 05/12/2019 - 09:53

i think Dennis Fouley does the best videos on YouTube regarding acoustics. spot on stuff with no hype nonsense intended to sell over priced treatments like Ethan Wiener. he has a grasp on all aspects including diffusion (which i have been going on about for years). between Foley and John Sayers there is a boatload of great information available.

kmetal Sun, 05/12/2019 - 12:54

jerem1, post: 461009, member: 51587 wrote: For the green glue I will see. I'm not sure it will be better to put thinner layers of mass than thicker layers in further to put more Green Glue. I red the specification of green glue and it's more for cracks and gaps. But i will follow you advice by putting more and thinner layers of heavy mass than thickers in further to have more green glue.

Green glue is spread over the underside of a sheet of mass.

You want to use the thickest sheets possible.

Green glues main use is for tight spaces like basements, where building code dictates a mimimun ceiling height, and adding the additional sheets of drywall, instead of glue, would take up too much space.

jerem1, post: 461009, member: 51587 wrote: I think that the thickness of my walls is correct and can not do much more because I will lose too much space. Maybe i can try to make walls a little thicker because you seem to say they are too thin. I did not understood that : "Drywall thickness- we use generally 5/8" (15.8mm) layers of sheathing here for studio purposes. 5.4mm (1/4") drywall is very, very thin. A typical studio uses 2-3 layers of 15.8mm, so your looking at 6-9x layers of 5.4mm to meet this criteria." Simply, in all how much do the walls of your studios in mm or cm or inch ?
More precisely, you saw that I have two thick bearing walls, then two walls completely to create, and I gave precise thickness and the composition of my walls, what thickness did you usually see ? The Wall A is 20cm and for this studio ? Wall A is 20 cm and the others around 14 (because there next to a bearing wall).

In typical double wall assembly, especially for drums you'll use 3x layers of 5/8" drywall on each wall, and a minimum 1" space between walls.

3 layers of 5/8" drywall = 1.875 inches thick.

A single 5/8" thick sheet weighs roughly 2.2 lbs per square foot.

So each wall in a double wall assembly has 1.875 inches thick of mass, and a density of 6.6 lbs per square foot of mass on each side.

The density is the key factor. If you could get a single sheet that was 6.6 lbs per sqft, it will work equally well as several layers of drywall.

Its about the mass.

jerem1, post: 461009, member: 51587 wrote: Im assuming your leaving an airspace between the existing drywall and the new rockwool/mass layers correct?". The spring, the air is assuming by the rockwool it's the air, the spring in the "mass-spring-mass" system). So don't need airspace in the walls because the rockwool il a soft

Rockwool is not a substitute for air space, or purpose built clips.

Rockwool has two roles for studios- acoustic treatment, and to meet fire code where required. It can be used for floating floors to reduce impact noise (footsteps) but not airborne noise (Sound).

Rockwool is an expensive alternative, and offers less sound attenuation in the low frequencies, than standard pink fluffy insulation.

There is No Reason to use rockwool in wall cavities unless fire code requires it. Its otherwise a waste of money.

Pink/fluffy R-value insulation is what to use behind walls.

jerem1, post: 461009, member: 51587 wrote: I'm gonna read Rod's book right now.

The drawings in that book are better than i can do. Congrats, that book is the best investment you can make in your studio.

jerem1, post: 461009, member: 51587 wrote: For the ceiling here is some picture of what i am gonna do simply, except that i am gonna glue to the original ceiling some heavy mass (because even it' the only thing i see to reinforce the original ceiling before building my suspended ceiling) and closing the ceiling with a "sandwich" of ba18/heavy mass/ba13 :

https://fr.audiofan…

But if you can do a draw of what you're proposing for the ceiling and maybe for the walls it will be really much easier for me to understand. For me simply i build the walls as i said and after a make the suspended ceiling as i described above with links, pictures.

The ceiling depicted has several problems.

1. Its got only a single layer of drywall.

2. It uses rockwool instead of standard insulation.

3. It is structurally coupled to the existing ceiling. There needs to be an airspace between insulation and ceiling above.

4. It may not have used proper isolation hangers.

Im in a painfully long process of moving. All my computers are packed up, i have nothing but a cell phone available to me. I cant easily draw stuff from scratch. The drawings in the book are a useful reference point. Youll have to pm me the drawing and i can explain it publicly, to avoid copyright infringements of the book.

A apologize, that i cannot just do some sketchup drawings like i typically would.

jerem1, post: 461009, member: 51587 wrote: You seem indeed to have a different idea for example when you said : "you may want to consider a new set of wood framed walls and a wooden ceiling frame resting on the walls, below the existing drywall/ceiling.". But

The pictures you linked are sort of what i was referring to. A suspended ceiling frame, insulated, with mass layers added. They make proper isolation hangers built to isolate the frame properly and support a decent amount of sheets of drywall.

You cant just use standard eye bolts to hang the ceiling from. You need purpose built isolation hangers.

There is a clear drawing of a massive, suspended ceiling frame in the book. It notes the proper hangers.

Lets use that as the illustration i was reffering to.

 

 

kmetal Sun, 05/12/2019 - 13:10

jerem1, post: 461010, member: 51587 wrote: Here is a critical video about Green Glue :

This video has shades of truth and shades of BS.

It is pure blasphemy that GG is just glue, and any standard adhesive works just as well. In fact its well known using standard building adhesives is not just worse than green glue, its worse than two sheets of drywall without the adhesive! Two sheets need to vibrate independently.

GG is an elasto-polymer and never completely hardens. This disperses vibrations. Its got nothing to do with sealing everything to do with dispersion.

There is Absolutely no single wall assembly, or dense sheathing that can even come close to a double wall assembly in performance, or cost. Hes simply wrong. Physics dictates that decoupled mass is what blocks sound best. Thats why studios do it that way.

He supplies no refference data to support his numbers presented. GG test data is presented in rods book.

It is true that GG is not as effective as 5/8" drywall in the lower frequencies.

GG is about 1.5x more expensive than drywall its drywall equivalent. That becomes equalized when you figure the cost of labour involved with the installation, of additional drywall layers, mud/tape, and caulking.

He makes a blanket statement that a 10$ sheet of drywall is superior to GG but doesn't account for cost of installing or the regional difference in prices per sheet.

GG is a compromise and used where space doesnt allow more effecient methods of gaining isolation.

jerem1 Sun, 05/12/2019 - 13:38

Thank you it's perfect. You did a lot and many greats advice.

Fot the book i have it and i will read it before doing anything.

- For the Rockwool i'm really not sure because i asked acoustician and sound engineers and they told me that rockwool is always better that air, not so much for acoustic (a little bit better) but for low frequencies. So as "spring" in mass-spring-mass rockwool or something like will be always better. That's what they said.

I'm waiting for new answers and will be back if something contradicts that.

- For the green glue i think you're right, it could be a very good thing (as described by the company) when you use it between 2 raw, hard materials as plasters, but between an elasticer and softer (even if it has a big weight) as heavy mass, i am not sure the green glue will be so effective (for the price). As the company describes it, it's effective between 2 raw materials as plaster to attenuate vibrations, but between a very dense and elastic material, anti vibratil as heavy mass, there is no significant meaning, reason to put some. i'm quite sure of this.

- You may be right for the ceiling (pity you can't do a little draw but don't worry i will check in the book). For me as i said before it's mass (actual ceiling + heavy mass i glued to it) is the first mass, after we have rockwool (it is the spring), and after the last mass. So mass, spring, mass. Exactly like the pictures i linked from "Audiofanzine" and you said that was good so i'm not sure to understand. But you may be right, maybe, there is 2 options : first a suspended wall with rods and sustainers/eye bolts directly on the original ceiling like in the picture of "Audiofanzine" i send. Or second option like you also said, create an empty space, air form the original ceiling and after creating a mass-spring-mass. I think i understand and i will check book if it's in it. WAt the moment without a draw i'm not sure to see exactly how to do that 2nd option, but i will check this seriously, maybe i need to create after the original ceiling a space of air and after that building a mass-spring-mass ceiling. I will check the book and advice.

So the pictures i linked are exactly what i explain from the beginning and what you said it's ok (except in the picture he forgot i think the sustainers/eye bolts directly on the original ceiling) but maybe it was not clear when i described from the beginning doing a suspended ceiling like in those picture. The only difference between those pictures and what i want to do is that i want to glue some heavy mas at the original ceiling ; that i would put 170 mm rockwool so less than in those pictures ; and we see in the pictures that the longs shrouds, rods, will not be directly fixed on the original ceiling like in the picture but il will use acoustics sustainers like that (that's maybe the eye bolts you talked about). I gave this link in my first post, message :

https://www.acoustique-studio.com/sustainer-p25-10-pieces-c2x9061918

Best regards.

kmetal Mon, 05/13/2019 - 14:58

Ive never seen an isolation assembly that had its mass coupled to the existing structure. There needs to be an air gap between the rockwool and existing structure. I am 100% sure of that. Otherwise it couples the structures, short curcuiting the isolation.

In order to do your ceiling you must:

1. Verify the existing ceiling can handle the weight of upstairs and your new assembly. A structual engineer can do this.

2. Use proper isolation hangers. (See picture)

3. Remove existing drywall, or verify that the isolation hangers will work with the existing drywall still there.

4. Make sure you have the proper mass (drywall) to block drums

5. Apply Green Glue only where directions say to, if you use it.

The drawings in the book should clear things up more.

I may be misunderstanding you, but are you thinking the rockwool can be used as mass? If so, this is not a correct use of it. Rockwool is simply to dampen resonance in the wall cavity, like a tea towel on a drum head or moon gels.

Notice in the picture the insulation never touches the existing ceiling.

This is a link to isolation hangers:

https://www.pac-intl.com/rsic_whi.html

jerem1 Tue, 05/14/2019 - 05:14

Hi,

Thank you very much.

- The question about knowing if rockwool which must absolutely not touch the wall is interesting and i trust you, maybe i am totally wrong and made a big mistake by thinking it's possible.

I need to check in Rod's book and follow you're advice because you said you sure of it.

I just tell you why i thought (in my mind) that rockwool can touch the walls. Is that in contrary of 2 raw, hard materials as wood or plaster that need indeed absolutely being separated by an elastic and soft material as Confort-Silence or heavy mass (link under here), or better by air, rockwool is a really softer material and i thought because of that it will not create phonics bridges if touch the walls. I really need to check Rod's book because i did not know that even rockwool need to no touch the walls. I will check Rod's book and the the guy help me (he is professional, not me) because i don't know how the rockwoll can be keep up, maintain standing in the wood structure without touching walls ? It's an idiot question but actually i don't know how it maintain standing, keep upright in/on the wood structure, but i am sure the guy help me know it (and i will check Rod's book). But what's important here is that you tell me that rockwool must not touch walls (bearing walls or plaster ba13). So i just need to check also by the way how it standing.

Another thing important, same subject, is that i don't know also if the wood structure need to be separate of the walls by Confort Silence or by air ? So if it's by Confort Silence what i thought to do, there is no problem understanding that the wood structure is not touching walls because there is Confort Silence in between. But maybe i am also wrong here, maybe the wood structure and the walls needs (as rockwool) being separated by air ? If yes, same question, how it maintain standing, keep uprigh,t if the wood structure si not resting on Confort silence (and the Confort Silence glued to walls) ? It's an important question i just forgot to ask because i thought Confort Silence are that kind of soft, rubber material used in between to "hard" materials as wood and plaster.

I have Rod's book in pdf but i need to translate it in french with the tool "Translate" in Word.

https://www.amazon…

https://www.greengl…

- The link for the Resilient Sound Isolation Clip RSIC-WHI® is great.

I don't see so much difference from what i send you but i will check with the guy that help me the difference and the product he prefers. Here is again the sustainers i wanted to use and if i am not wrong it's quite the same thing :

https://www.acousti…

Si as we said for the walls, the fact that rockwool do not touch the walls, i will do also the same thing for the ceiling, rockwool will not touch the original ceiling.

And it's difficult to know if my roof will be ok to block my drum, but that's what i'll do : create a suspended ceiling with rods and after or my sustainers (in the link above) or yoyr Resilient Sound Isolation Clip RSIC-WHI® but i think it's quite the same thing (i will check withe the guy help me what he prefer) . So doing a suspended wall exactly as the Resilient Sound Isolation Clip RSIC-WHI® pictures you send me. In that suspended wall i can put 170 mm (17 cm) rockwool (rockwool not touching the original ceiling as you told me), so as you see it will be almost full of rockwool ; and closing it if possible with a "sandwich" of ba18mm/heavy mass 5.4mm/ba13m.

All this new ceiling is doing 20 cm (in addition to the original ceiling, i send a draw upper). What do you think ? Does that 20 cm suspended ceiling in addition to the original ceiling and with those different juxtapositions i just described, dos it seems ok for the drums ?

I wanted to glue also a thin layer of heavy mass to the original ceiling but il i don't know if it's possible. I'm not not sure this will stay in place in the long run. Il will see with the guy help me if there is a solution.

And yes i will check if the actual original ceiling can bear the weight of that suspended wall. I think the guy helped me and did the draw above of my original ceiling know what that original ceiling can support because he dug into the structure few months ago (for different reasons not interesting to say here). Once again a can't dig into the original ceiling to rebuild again, so as in the pictures you send and the pictures i send, the rods will go simply from the actual ceiling but we will be very very careful finding solid places to put the the rods.

So to conclude on you last question, yes maybe i am wrong to put so "much" rockwool in relation of heavy mass because i most important for insulation (neighbors) is heavy mass but what i can do to tu put more heavy mass that put some on the original ceiling (if possible) and put some at the end, when closing the suspended wall with (if possible) a "sandwich" of ba18mm/heavy mass 5.4mm/ba13m.

Thank you.

jerem1 Tue, 05/14/2019 - 08:08

For the ceiling i rectified a little bit (but i'm goona read Rod's book soon) :

- Ceiling (for the ceiling I am less technically certain of what to do but here is a possibility) : (first if possible) stick / fix a layer of 5.4 mm heavy mass to the current ceiling (I do not know if this is possible) ; then fix (before or after this heavy mass?) the rods, suspension and at the end of rods sustainers and the rail ; put over the rail/structure 170mm rock wool (which should not be touching the original ceiling and maybe few mm of aire between the rock wool and the actual ceiling is enough (or the heavy mass if I can paste) + close with a sandwich ba18 and acoustic ba13 so between the two 5.4 mm heavy mass = 22 cm

For example: https://img.audiofa…
https://img.audiofa…
https://acoustique-…
https://www.mecanoc…

Or it looks like what I want to do except instead of putting like this drawing 2 ba 13 and between the two a 15 ba, I would like to put 1 ba18 and 1 ba 13 with between the two of the heavy mass, plates 5.4 mm, see two 5.4 mm plates if possible, if the current ceiling can support the weight:

https://img.audiofa…

- And for the wood structure/frame for the walls here is some examples, and i though as i said above that walls and the wood structure will be separate by the Confort Silence. But maybe here also i am wrong and it need to leave air between wood structure and walls and not Confort Silence ? If yes i don't know yet how to do it.

Here is an example of a wood frame:

https://img.audiofa…

https://img.audiofa… en & identifier = image & size = normal & module = user & userPhoto_id = 280134

https://img.audiofa…

kmetal Tue, 05/14/2019 - 09:06

As long as the rods/sustainers manufacturers paperwork verifies that they are ok for use without removing the existing drywall, and can support the amount of weight your intending to use, then i don't see any issue with them. The caulking details for the perimeter are outlined in the book.

For the walls im not sure what comfort silence is, but generally you'll want to leave a 1" airspace. You fasten the new walls to either the isolation ceiling, or use isolation brackets at the top. You nail or screw the bottom wall frame to the floor.

This picture you linked describes what i meant by "a ceiling frame resting on the walls". If you can do this, you'll acheive the best isolation, at the lowest cost. Notice the ceiling frame doest touch the existing drywall. This is the best design you can shoot for.

https://img.audiofa…

-----

These are the clips used to attach your walls to the existing ceiling, or existing walls. I would verify with the manufacturer if you use them without removing the existing drywall.

Ive used these in a high end home theater build along with risc-1.

---

These clips are seem to be designed to be used when existing drywall cant be removed.

https://www.pac-int…

kmetal Tue, 05/14/2019 - 09:12

Green glue comes into play with the clip systems since they generally dont support more than 2 or 3 layers of 5/8" drywall. GG gives you the the closest equivalent to 3 to 5 layers of drywall, when clips are involved.

Some heavy duty clips support more than 2 or 3 drywall layers. This is where cost versus benefit must be anylized.

jerem1 Tue, 05/14/2019 - 11:32

Thank you very much again for your help. I appreciate a lot, it helped me a lot. Hope this thread will help others. Also sorry for my English.

- For the GG I immediately note the info and will see, be careful also which sustainers/clip systems can bear the weight.

- For the wood frame structure of the walls i get the information, i understand now that it's gonna be fixed in the ground, soil, and acoustician told me this at the same moment you told me (sorry i'm bad, i thought is was fix not from the soil but the walls..., and no, it is fixed from the soil i just understood). So it will stand up because fixed in the the ground, soil. So i don't need the Elastomer/ Confort Silence between the walls and the wood frame. So there will be only air between the walls and the wood frame because the frame is fixed on the ground, soil. So i understand that in the picture the wood frame is fixed to the soil, that's why it stand up : https://img.audiofa…

So if the wood frame of the walls is fixed on the soil, i think i don't need for the walls the Rsic 04 but only the Rsic 01 to close the walls.

I saw also indeed in your pictures and comments that there is few options of clips for the ceiling plaster and i will see which one i can use directly on my original, actual plaster ceiling. There is indeed few products (Rsic DC04 etc...) to fix on this plaster ceiling and it's difficult to see which one can be better directly on the ceiling. Yes indeed i can't remove the dry wall so i need to fix on the plaster ceiling.

But i still don't know how the rock wool will stand up on the frame ? It must be obvious, but I am bad and ask now or will ask the guy who gonna work with me.

- For the wood frame of the ceiling, the picture i send, i did not knew that i had to do for the wood frame of the ceiling exactly like in that picture, i did not knew that i need to make "a ceiling frame resting on the walls". I though that there is on one side the walls to be done first, then independently and after the ceiling. So i am not sure i need to do "a ceiling frame resting on the walls", because i can also do like those :

- For the ceiling i see of course completely what you mean by fixing rods directly to the actual/original ceiling. But for me just a layer of heavy mass may be better to reinforce that original ceiling and for sure it can't be worth than leave the ceiling as it is. But the problem will be technically to glue that heavy mass because i am quite sure it's risky because it not gonna stand a long time.

Indeed an acoustician told me that fixing heavy mass to the original ceiling is a good idea, it gonna reinforce this plaster of ceiling.

He told me also as you said that it will be difficult to leave precisely few mm between the rock wool and the original, actual ceiling, so it is better to provide few cm (like 3 or 5 cm).

- For the soil he told me (as you said also) that i don't any need heavy mass and also i don't need parquet. For him the best will be to buy carpet with Delta superior than 20 and Alpha superior than 0.3.

I see you're both right, i don't need to add mass on the soil because is is already mass. But i wanted to do it for "acoustic reverberations" and for this it is a carpet will be better in his opinion.

- And just to say, two acousticians told me that the best thing is no a suspend wall, but having a total uncoupling with this product (but they said it's to expansive). It's a kind of wall and ceiling pre-build. And so making the suspended ceiling and the walls from this pre-build structure, frame (but they said it is expansive) :

http://pdf.archiexp…

jerem1 Tue, 05/14/2019 - 15:55

Forget the question about the wood structure, frame, i was asking : "why using this technique on this picture : https://img.audiofa… and not that kind of ceiling : https://img.audiofa…
or https://acoustique-… or https://acoustique-…

I just understood, and again you're right, it's logic, because if i suspend the ceiling directly on the original ceiling like in those latest pictures, there will be more phonics bridges, air, feather-light bridges when i hit the drum, and also solid bridges when my neighbors are walking upstairs. So in the first picture the wood structure is completely disconnected from the original, actual ceiling. So i can begin the suspended ceiling form that wood frame, structure that is so completely disconnected of the original ceiling.

It's perfect. And also i don't need that expensive product (and also i checked it doesn't exist for smalls rooms) http://pdf.archiexp… because it is exactly the same principle as that wood structure in that picture again : https://img.audiofa…

The other advantage of that wood walls and ceiling structure together is that i can choose kind of wood and thickness that can bear the suspended wall i'm gonna fix to it.

Thank you.

kmetal Wed, 05/15/2019 - 11:52

jerem1, post: 461042, member: 51587 wrote: So if the wood frame of the walls is fixed on the soil, i think i don't need for the walls the Rsic 04 but only the Rsic 01 to close the walls.

Risc 04 would be better for supporting walls at the top. Risc 1 requires hat channel wich is more money and labour for no benefit.

jerem1, post: 461042, member: 51587 wrote: There is indeed few products (Rsic DC04 etc...) to fix on this plaster ceiling and it's difficult to see which one can be better directly on the ceiling. Yes indeed i can't remove the dry wall so i need to fix on the plaster ceiling.

The risc dc04 arent meant for when there is existing drywall. The risc 01retro clips are. Verification is needed for the isolation hangers, when existing drywall is involved.

jerem1, post: 461042, member: 51587 wrote: But i still don't know how the rock wool will stand up on the frame ? It must be obvious, but I am bad and ask now or will ask the guy who gonna work with me.

Its stuffed into the frame, friction holds it in. You can also use a metal retaining wire or strap, or poly (plastic) vapor barrier.

jerem1, post: 461042, member: 51587 wrote: - For the wood frame of the ceiling, the picture i send, i did not knew that i had to do for the wood frame of the ceiling exactly like in that picture, i did not knew that i need to make "a ceiling frame resting on the walls". I though that there is on one side the walls to be done first, then independently and after the ceiling. So i am not sure i need to do "a ceiling frame resting on the walls", because i can also do like those :

This is your best bet for blocking drums, and ease of construction, and low cost. Its drawn in the book.

jerem1, post: 461042, member: 51587 wrote: Indeed an acoustician told me that fixing heavy mass to the original ceiling is a good idea, it gonna reinforce this plaster of ceiling.

The best place for mass, for isolation, is on your new ceiling. If plywood or other things are needed for structural reasons, a structural engineer can confirm this.

The advantage of the "wood frame ceiling on walls" is it doesnt add any additional weight on the existing ceiling, and will not require any additional mass to the existing ceiling generally speaking.

jerem1, post: 461042, member: 51587 wrote: He told me also as you said that it will be difficult to leave precisely few mm between the rock wool and the original, actual ceiling, so it is better to provide few cm (like 3 or 5 cm).

At least 1" air gap is minimum between isolation walls / ceiling, and the existing structure. More is fine, less than 1" is not good.

jerem1, post: 461042, member: 51587 wrote: And just to say, two acousticians told me that the best thing is no a suspend wall, but having a total uncoupling with this product (but they said it's to expansive). It's a kind of wall and ceiling pre-build. And so making the suspended ceiling and the walls from this pre-build structure, frame (but they said it is expansive) :

jerem1, post: 461049, member: 51587 wrote: I just understood, and again you're right, it's logic, because if i suspend the ceiling directly on the original ceiling like in those latest pictures, there will be more phonics bridges, air, feather-light bridges when i hit the drum, and also solid bridges when my neighbors are walking upstairs. So in the first picture the wood structure is completely disconnected from the original, actual ceiling. So i can begin the suspended ceiling form that wood frame, structure that is so completely disconnected of the original ceiling.

Yes sir! Its drawn in the book.

jerem1, post: 461060, member: 51587 wrote: For the floor soil for sure there is mass and i can't do something on anti-vibratil studs.

So the main question is more about treatment i guess and i don't know which one between a dense carpet and heavy mass could absorb better the middle or low frequencies ?

For acoustics, carpet is fine. At a commercial studio i build, in the drum room, we painted the concrete floor, and put a regular area rug under the drums, and are happy with the results.