"The MDF just adds more mass to the wall,"
It adds first, structural rigidity, but yes it adds mass, but mass is not the only benefit. In most cases, it is better to instal OSB, but any type of sheathing will make for a more rigid and safer structure.
Octagonal small Studio plans for Studio in Thailand
Originally posted at johnlsayers.com, topic 16953.
The OP was specifically asking "could you please explain further the MDF's benefit to the MSM?" Sure it adds structural strength and nailing surfaces and all those good things, but the question was about how it affects MSM. And what MDF does to MSM is to add more mass.
- Stuart -
Yes Stuart, that makes sense to have the Mass part of a MSM to be as "mass"-ive as possible..And I have found some 3cm thick MDF that is nice and heavy.
I'm still unsure on how to deal with the doorway& door(s) area, so if you have any thoughts on this ,they will be greatly appreciated..
I peruse...I do not line by line these long posts...pick up the highlights and run with that, is what I do. The question was moot to me since we should all understand the benefits of insulation to damp panels...and if you are considering a heavier mass on the first layer, you should have that information available as well. What we do not know is what the rigidity does in respect to the assembly and that usually comes in the form of testing the room after completion.The OP was specifically asking "could you please explain further the MDF's benefit to the MSM?" Sure it adds structural strength and nailing surfaces and all those good things, but the question was about how it affects MSM. And what MDF does to MSM is to add more mass. - Stuart -
Hello ban sabaii, from other threads i know if the door and doorframe is heavy and closes airtight to the building structure, there should not be a problem. the door should sit in the inner construction as well. In some or other thread are free sketchup example studio files from John... You can use it to adopt the doorframe and doorconstruction very nice to your build. Here is also a great discussion + sketchup file of a door construction. That might be good too. I have not saved all links to my favorites but this might be helpful: http://www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=14698&start=15 scroll down to the door pics. http://www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=12664 studio door discussion with sketchup files and pics. Very interesing. what is the exact point you are unsure with the doorway? kind regards Aaron... I'm still unsure on how to deal with the doorway& door(s) area, so if you have any thoughts on this ,they will be greatly appreciated..
Excellent!!! Thank You Aaron!! :)
you also should consider what xSpace said. I mostly saw OSB or chipboard behind the plasterboard. MDF might be have more weight but it is terrible to drill... So for this reason i would consider using OSB and one more plasterboard layer for getting the perfect match together - weight, drill benefits, stability....In most cases, it is better to instal OSB, but any type of sheathing will make for a more rigid and safer structure.
Yes OK Aaron thanks again.. I will look for OSB sheets down here; I think they are fairly easy to find and relatively inexpensive
Plasterboard on the other hand, is fairly expensive down here.. so I would prefer to go with a thicker layer of OSB ( about an inch if I can find it) and a single max thickness layer of plasterboard I can find( i think @ 3/4") .
please check if one layer plaster board is anough in your situation.
I think Stuart can answer this question but my feeling says you need 2 thick plaster boards minimum.
kind regards
Aaron
There is a reason you see OSB or PLYwood rather than MDF. MDF will chip/break when it has force exerted on it, screws can blow holes through the back and weaken the sheathing. Heck hit it with a 3 pound hammer and it breaks like a glass window :) That is why an orientated strand board(OSB) or a 5 ply/ plywood is a better substrate.you also should consider what xSpace said. I mostly saw OSB or chipboard behind the plasterboard. MDF might be have more weight but it is terrible to drill... So for this reason i would consider using OSB and one more plasterboard layer for getting the perfect match together - weight, drill benefits, stability....In most cases, it is better to instal OSB, but any type of sheathing will make for a more rigid and safer structure.
Just noticed your thread as i googled about plasterboard.If you havn't finished(or started) your studio yet i would recommend that you build your external wall solid concrete with metal rods(re-bar) at least 100mm but 6" would be nicer.
Your soundproofing will be far greater than rendered breeze block,which can sometimes be hard to fix to.Not to mention 10x stronger,but primarily for acoustic purposes.I know it will be quite a bit more cost wise,but you'll find it was worth it.Rockwall and DOUBLE plasterboard,12.5mm a sheet,either side of the rockwall are about standard if you are soundprooofing an internal wall in an office enviroment(important meeting room).
Rubber matting is also a great,but heavy,material used for sound.With regard to your door(s) i used to make soundproof doors and acoustic panelling when i lived in the UK.We made 100mm thick doors comprised of 2x20mm thick boards which were either veneered or melamine finished,held together with tough metal brackets inside.The 60mm space inside the boards would be rockwall,and the really heavy and great acoustic doors would have 1 or 2 layers of rubber matting stapled to the inside of each of the boards.This provides excellent soundproofing quality,about 50-53db rating....but they were real heavy,usually because the average height was more than your standard 2 metre door(about 2.5 metres).If you take my advice be sure to hinge it well.By the way silver-faced rockwall is a great way to reduce heat,a bit like loft-insulation but is not cheap.Good luck but remember the thais love a bit of concrete here!
Thank you very much for your tips about the door soundproofing and the solid concrete wall.
As of now, we have already begun the build with the breeze blocks ( which are solid 10 cm ones and not the typical ones with the air gaps.)There will be about a 2 inch layer of Cement render on the front side of Would you recommend rendering the inside of the brick wall as well?
Due to the width of the layers of Bricks/air gap and inner wall, we will have a door frame area of about 50 cm deep, so we were planning on an inner insulated door and an outer Security door...how does this sound?
Also ;seeing that this room will only have an AC unit as it's sole incoming air supply , we will need to have stale air exhaust ducting..However I am not sure on the best way to do this in order not to effect the sound proofing of the room in any way..Any comments anyone?
Many thanks...
You have to render the inside of the wall as well,because those blocks are not strong enough to fix anything to...i mean you cannot drill into them,they just crumble.Therefore an inch or so of render will help,for a fix,but it is not ideal.You know the small red bricks here....when they are laid and then rendered are very strong,much more so than the blocks.This is a big point because you will have trouble later on,and if you are still using MDF or Ply you will have to 'gripfill' the boards to the external wall.This is not a problem but the tradesmen need to be a bit clued up to do this to a standard which is satisfactory.
Having an internal and external door provides a good vacuum in which sound cannot travel so well.Assuming you have a substantial outer door in mind,the interior of your studio is going to be decorated ? When i say that i mean you can add to the acoustics by making up (or buying ) panelling which absorb sounds,bit like a padded cell in a nut house,which you would continue to finish the inside of your internal door.(Hope you follow what i mean)
You must have an extraction fan,at least one decent sized,i assume you will be smoking etc.
You might consider putting a window in,a well made double or triple glazed has good acoustic properties,and the extraction fan will not let much noise out so i would not worry about it(if you have a wall which faces nobody put it that side).
One bit of advice i will offer is don't leave the site....unattended Thai workers equals mistakes,so don't let them work their way...you'll only have to re-do it later.I have found their rendering and tiling work here to be of a pretty high standard if you have 1 or 2 good tradesman in the crew...
Sorry, but that would be a bad idea for many reasons. First, 12.5 mm plasterboard is never recommended for optimum isolation: it is too thin, too flexible, the mass is too low, and the resonant frequency is too high. A bad combination. You should never use anything less than 15 mm, preferably more. Secondly, unless the two sides of the wall are fully decoupled, it makes no sense to add extra layers of drywall. Doubling mass on a coupled wall will only yield 6dB of increased isolation, in the very best case, and it is more likely to be around 3 or 4dB. Not sure what you meant by "rockwall": was that supposed to be "Rockwool"? And finally, "soundproofing" is impossible: a sufficiently loud sound will penetrate any conceivable barrier. You cannot stop sound: all you can do is attenuate it.Rockwall and DOUBLE plasterboard,12.5mm a sheet,either side of the rockwall are about standard if you are soundprooofing an internal wall in an office enviroment(important meeting room).
In what way is rubber matting "great for sound"? Where? What type of rubber? For what purpose? What deflection under what load? Such a broad generalization is not very helpful, and indeed could cause major problems for someone who does not understand acoustics. Rubber is only useful in acoustics when the purpose is defined, and if the purpose is to act as a decoupling spring, then it is only useful when the deflection is correct for the amount of loading. Otherwise it is useless.Rubber matting is also a great,but heavy,material used for sound.
Ummm.... let me try to understand: You are saying that a hollow core door makes a good acoustic isolation door? :?: :shock: :!: You are kidding, right?With regard to your door(s) i used to make soundproof doors and acoustic panelling when i lived in the UK.We made 100mm thick doors comprised of 2x20mm thick boards which were either veneered or melamine finished,held together with tough metal brackets inside.The 60mm space inside the boards would be rockwall,and the really heavy and great acoustic doors would have 1 or 2 layers of rubber matting stapled to the inside of each of the boards.This provides excellent soundproofing quality,about 50-53db rating....
Vacuum? Huh? :shock: :?: How do you create a "vacuum" between two doors? You have some type of air pump in there, that sucks out all the air? :shock: If not, then you don't have a "vacuum" at all. The purpose of building a proper soundlock is NOT to create a "vacuum" between the doors, but rather to create a tuned MSM system whose resonant frequency is lower than the square root of 2 times the lowest frequency that you need to isolate. "vacuums" have nothing at all to do with it.Having an internal and external door provides a good vacuum in which sound cannot travel so well.
Is this a joke? Do you have ANY idea what you are talking about? :?:you can add to the acoustics by making up (or buying ) panelling which absorb sounds,bit like a padded cell in a nut house,
Actually, ordinary double glazed windows are no use at all for effectively isolating studios, and triple glazing is even worse! Those types of windows are fine for homes and offices, where the purpose is to isolate the mid range and highs, but they are pretty useless for studios, where the most important part of the spectrum is the low end, exactly where ordinary double glazing is lousy, and triple is even worse. - Stuart -You might consider putting a window in,a well made double or triple glazed has good acoustic properties
Hi Stuart,sorry if i touched a nerve...didn't realise my suggestions could raise your blood pressure :shock:
Firstly,i never implied i had the answer to completely stop sound...i can't run that fast.Soundproofing is a word used as a generalization,it does not actually mean there will be silence..although that would be golden.
I wrote,if it was unclear i apologise,DOUBLE (2)sheets of 12.5mm plasterboard-Rockwall,insulation,mineral wool,(any of those terms i think are understood)-then 2 more sheets of 12.5mm plasterboard.Effectively 4 layers of 'drywall' with insulation as the filling.This is a tried and tested method,so yeah,i do know what i'm talking about.
Rubber matting,i personally used to use pieces which were similar in size to carpet tiles,about 10mm thick,but roles/sheets can be obtained to line walls.
Hollow doors? I wish they were because they would have been a lot easier to fit.I said the door was 100mm thick. Two 19mm MDF panels,finished in either a melamine/formica or bookmatched 1 to 2 mm veneer.These panels would sandwich the 50mm Rockwall/insulation and the inside of the panels held the rubber 'tiles'(a good sound reflector).All these materials add up to approx.100mm.
The space between the internal and external doors acts as a dead area,which bounces the sound reducing it in the process,unless you stand there with both doors open,although i'm not too sure cos i've only built a few nightclubs so i don't yet have the necessary experience...i'll have to get back to you on that one.
Padded cells.....i'm trying to put all that behind me,terrible flashbacks.....and the window,that was so i could escape my white wonderland...it's not fair to have a jacket with the buttons on the wrong way,takes too long if you really need to use the toilet.....memories,silence is golden!
Hi Stuart..
Could you please comment on an efficient way to ventilate and extract stale air from our room. My concern is to have the room open to fresh air via ducting(?) yet at the same time , not effect the dual leaf isolation that we are creating. Is there a industry standard method for studio ducting
(please check the original attachment of the Rectangular floor plan for our room)
many thanks
One more time: No you do not. from your description, you are NOT decoupling the two leaves, therefore the isolation is limited by flanking. That wall will get you STC-thirty-something, tops, and will be lousy in the low end, like all coupled walls. One more time: 12.5mm plasterboard is too thin, no matter how many layers you put on: it is too flexible for good isolation below MSM resonance, where rigidity governs, the mass is too low, and the fundamental resonant frequency is too high. One more time: there is no such thing as "Rockwall" (unless you are referring to the city of that name in Texas). It is "Rockwool", which is a trade name for a specific brand of mineral wool. The generic term is "mineral wool". One more time: unless you fully decouple the leaves on an MSM system, maximum isolation is limited due to the flanking paths. The only thing "tried and tested" about fully coupled flanked walls with four layers of 12.5mm drywall is that they are pretty lousy isolators. Take a look at IRC-761 and IRC-754 to see how well that works, in actual "tried and tested" laboratory research. You'll can find the real "tried and tested" exact test data on page 26 of IRC-761. The result is as expected: STC-38, primary resonance at 125 Hz, huge coincidence dip at around 3 kHz. On page 21 is the test data for a wall built the same way, but with only a single layer of plasterboard on each side: STC-34. In other words, by adding your extra layers of plasterboard on each side, all that you accomplish is a tiny increase in STC from 34 to 38. Not even noticeable! And you claim to know what you are talking about? :shock: One more time: Unless you decouple the leaves, you cannot get isolation any better than the mid 40's, tops. The laws of physics prevent it. Decoupling and tuning the wall's MSM resonance is the ONLY way to get high isolation.I wrote,if it was unclear i apologise,DOUBLE (2)sheets of 12.5mm plasterboard-Rockwall,insulation,mineral wool,(any of those terms i think are understood)-then 2 more sheets of 12.5mm plasterboard.Effectively 4 layers of 'drywall' with insulation as the filling.This is a tried and tested method,so yeah,i do know what i'm talking about.
I'm not questioning that you use it: I'm questioning that you did the math! What loading do you put on your "rubber pieces"? How much deflection does that loading cause? If you don't do the math, how do you know if it is floating or not?Rubber matting,i personally used to use pieces which were similar in size to carpet tiles,about 10mm thick,
Ummm... it's not ME saying they were hollow: YOU said they were hollow! I quote: "The 60mm space inside the boards would be rockwall,...". 60mm space inside the door filled with non-existent "rockwall" is, undoubtedly, a hollow-core door. It will resonate, and the isolation in low frequencies will suffer. From the method you described, primary resonance will be around 50 Hz, so the door will not isolate at all under 67 Hz, and will not isolate well until roughly 144 Hz... :shock: You even confirmed that your doors are hollow-core, right after denying it: "Two 19mm MDF panels,finished in either a melamine/formica or bookmatched 1 to 2 mm veneer.These panels would sandwich the 50mm Rockwall/insulation" Yup, that sure is hollow core! Except that the air gap shrunk from 60mm to 50mm, so now the primary resonance went up to 54 Hz, and the door doesn't isolate well until 158 Hz...Hollow doors? I wish they were because they would have been a lot easier to fit.
Ummmm.... Actually, no it does not. The space between the doors is a resonant cavity, and the primary resonance is calculated with the equation f+ = (1/2π)√((3.6 ρ c^2)/(m d)). The isolation in a sound lock has nothing at all to do with "bouncing the sound to reduce it in the process". It has everything to do with Mass-Spring-Mass resonance and the fact that the doors plus the air gap form a tuned bandpass filter. You might want to take a look at the Wyle report to get a better handle on the theory of isolation systems. - Stuart -The space between the internal and external doors acts as a dead area,which bounces the sound reducing it in the process
Yes, the standard way is to use ducting that is lined on the INSIDE (not the outside) with duct liner, and to use silencers in line with the ducts, just before or after they go through the isolation wall. The ducts need to be over sized (double the normal cross-section), in order to make the air move slowly, and the fans should be as far as possible from the studio. If you need to feed more than one room from the same duct, put silencers in both branches. You can buy commercial silencers, but it is much cheaper to make them yourself. You need two sets of ducts: one to bring fresh air into the room, and the other to take stale air out. There are methods for calculating the amount of air that you need to pump through the room, depending on the room volume, number of people, etc. But the important thing is to keep the ducts isolated and decoupled from the building structure, and also decoupled where they pass between your isolation leaves. - Stuart -Could you please comment on an efficient way to ventilate and extract stale air from our room. My concern is to have the room open to fresh air via ducting(?) yet at the same time , not effect the dual leaf isolation that we are creating. Is there a industry standard method for studio ducting
I don't know where your hollow term comes from,i never mentioned it-let alone reiterated it.60mm never changed to 50mm,i didn't mention size,take the matting into consideration and the mineral wool(which actually i remember now was very compact) i don't see where hollow comes from ? Sorry i mistakenly wrote Rockwall instead of Rockwool,i have no idea about Texas cos i'm not an American cowboy.
What i said about the internal and external door was correct.
One more time;why are you concerned about the acoustic value of the plasterboard,when initially you moderately should have advised a solid concrete outside wall,not a breeze block structure no matter how it is rendered it will not be sufficient for a studio.
By the way you can get laminated glass (for the window) which has an STC value of 61,about 15mm glass.
Stuart can you please elaborate further on the ducting /ventilation system you described..
If you have any links or further info for DIY silencers, ducting layout plans etc , it would be greatly appreciated.
Any plans out there for construction of DIY studio doors ?
cheers...
Ummm.... Let me quote you directly: First post: "The 60mm space inside the boards would be rockwall " Second post: "... panels would sandwich the 50mm Rockwall/insulation" Hmmmm... I guess that change from 60mm to 50mm isn't really a change from 60mm to 50mm? You keep on insisting that the door is not hollow, yet you keep on claiming that there is a hollow space inside it, that is 60mm deep (or 50mm, sometimes). How can it not be hollow if you have Rockwool inside it???? Did you somehow manage to infuse Rockwool into the MDF itself? Let's take a close look, and analyze how your door is built: "I said the door was 100mm thick. Two 19mm MDF panels,finished in either a melamine/formica or bookmatched 1 to 2 mm veneer. These panels would sandwich the 50mm Rockwall/insulation and the inside of the panels held the rubber 'tiles'(a good sound reflector).All these materials add up to approx.100mm."To start with, rubber is NOT a "sound reflector" (unless it is extremely rigid rubber), but rather is a damper material, that can be used to decouple surfaces acoustically, when used properly. But it serves no purpose when used in the way you describe, except perhaps to damp one of the panels a bit, and maybe to add a tiny amount of mass to the door. But anyway, time to analyze: So the door is 100mm thick. It has two sheets of 19mm MDF, so 100 -19 -19 = 62mm. There is a gap of 62 mm between the sheets of MDF! There is no other way of explaining it. The door is HOLLOW: it has an air gap of at least 50mm, and maybe as much as 62mm in the middle. Hence, it is a hollow-core door. You say there is also rubber in there (which serves no acoustical purpose in the design you describe,as I already mentioned), so maybe that accounts for some of the space. You say "i personally used to use pieces ... about 10mm thick", so that only accounts for 10mm, leaving a 52mm hollow core in the door. That's the hollow core where you have your 50mm of Rockwool in there. Therefore, this is a hollow-core door with an air gap of roughly 52mm, mostly filled with Rockwool. so, one more time, it IS a hollow core door. No question about it.I don't know where your hollow term comes from,i never mentioned it ... 60mm never changed to 50mm
No it is not. One more time: Any time that you have two large massive layers on each side of and air chamber, you have an MSM system. This is not an opinion: it is simple, raw physics. There simply is no question about it. Mass on one side, the spring (air) in the middle, and mass on the other side. MSM. End of story. All MSM systems are undoubtedly tuned to a specific frequency, given by the equation I quoted above. The main factors are the surface density of the two masses, and the depth of the air gap between them. Hang a mass on a spring and it resonates, with the period being governed by the stiffness of the spring and the mass. Not complicated. Once again, this is simple physics, taught in most high schools! (Or rather, it used to be taught in high school in my day: maybe not these days.) So two large massive doors with an air gap in between IS a tuned system, whether you like it or not, and regardless of whether or not you understand how it works. Such a system will always be tuned to a specific fundamental frequency. At that frequency, the entire system dos not isolate at all, precisely because the sound is "bouncing around" like crazy, and resonating. So, exactly the opposite of what you said, it is not the sound "bouncing around" that causes isolation, but on the contrary, the sound "bouncing around" is what causes the system to NOT isolate at its resonant frequency. In fact, not only does it not isolate at that frequency, it actually amplifies sound passing through it.... At 1.4142 times the resonant frequency, the system starts to isolate, and at all higher frequencies it isolates increasingly well, much better than mass law (the rather poor principle that your wall is based on) up to the region of coincidence dip, where it loses isolation again somewhat, over a range and to an extent that depends on other factors. Above coincidence, it isolates once more, up through the rest of the spectrum. Below the primary resonance, the isolation of the system is governed mostly by rigidity. For this reason, the resonant frequency of the soundlock (two doors over an air gap) must be chosen such that it is at least 1.414 times lower than the lowest frequency that you need to isolate. Simple logic. The normal rule of thumb is to get it down to half of the lowest frequency needed. If you have not been doing the math in designing your doors, then you have no idea how they are performing, or what frequencies they are isolating and not isolating, where the coincidence dip is, and how deep it is. But your case is actually worse, since you don't have a simple 2-leaf MSM system: You have a 4-leaf MSMSMSM system, since each door is a hollow-core 2-leaf system itself. As everyone knows, the resonant frequencies of a 4-leaf system are way higher than for the equivalent 2-leaf system, and thus the system isolates extremely poorly over a large section of the low-frequency spectrum. Not only that, but since the region below resonance is governed by rigidity, and your thin 19mm panels are not very rigid at those frequencies, and aren't even damped properly, so basically those doors do not isolate at all below resonance. This is all simple, basic high-school physics. Nothing complex or questionable about it. No debate, no guesses, no opinions: Just pure, sound, solid physics, backed up by centuries of experiment, and decades or practical research in numerous independent acoustic research facilities. It is so well documented these days that there just isn't any doubt as to how an acoustic MSM system works.What i said about the internal and external door was correct.
Well duh! Why would I NOT be concerned about the most important primary factor in the MSM system of the walls? :shock: Why would anyone want to build a wall without first understanding the acoustic properties of the materials used to build it? That would be rather silly, wouldn't it? If someone tells me that I should use materials that have no acoustic value, or whose interaction with other materials in the same tuned system is detrimental, then of course I should question it, and be concerned about it!why are you concerned about the acoustic value of the plasterboard,
Nope! Not a problem. The acoustic principle in operation here is a tuned MSM system, where the major factors above resonance are mass (breeze blocks have plenty of mass), and air gap (the design calls for large air gaps), and below resonance the major factor is rigidity (a breeze block wall has plenty of that too). Concrete is an alternative, so is brick, so are plywood, MDF, HDF, OSB, drywall, lead sheet, steel plate, aluminium plate, and numerous other dense materials, provided that they are used CORRECTLY in a wall that is DESIGNED using the basic principles of physics and acoustics. Breeze block has a density similar to low quality brick, roughly 1900 kg/m3: Concrete is roughly 2200 kg/m3 (depending on type). Not much difference. Either is fine.when initially you moderately should have advised a solid concrete outside wall,not a breeze block structure
Who cares about the rendering? That wont make very much difference to the mass (although it helps, of course). Any type of airtight seal would work: even sealing the surface with a good quality paint sealant would do the job. Why are you so worried about the rendering, when it doesn0t even figure in the equations? The ONLY factors that matter are the total mass on the leaves, the air gap between them, the damping in the cavity, and an air-tight seal.not a breeze block structure no matter how it is rendered it will not be sufficient for a studio.
so now that you realized your gross error in suggesting that ordinary double glazing is a good acoustic isolator for studios, you did some research and found out that laminate glass is the correct approach? Hmmmmm.... I guess you will now try to pretend that "double galzing" and "laminate glass" is actually the same thing.... And no, there is no single pane of glass that will get you STC 61 all by itself, or at least not at a reasonable cost, and not that could be easily supported in a normal stud-framed wall. The only way to get STC-61 is with TWO panes of laminate glass over a suitable air gap, thus forming an MSM system, which is tuned by the mass of the glass on each side, and the depth of the air gap between them. (And no, we are not talking about double-glazed panel here). To get STC-61 by mass law alone, you would need glass with a surface density of at least 500 kg/m2. Normal glass has a density of about 2500 kg/m3, so you'd need a pane of glass roughly 20cm thick to get STC-61 all by itself! :shock: A piece of glass like that measuring 1m by 2m would weigh more than a ton. Literally! (You'd need a crane just to lift it into place!) In fact, you can easily get isolation of better than STC-61 with an MSM system of two panes of laminate glass, each less than 2cm thick, for a tiny fraction of the cost of what you proposed. But why are you quoting STC, when it is such a lousy system for determining the isolation characteristics of construction methods? STC does not even take into account the factors that are important for studio isolation.... - Stuart -By the way you can get laminated glass (for the window) which has an STC value of 61,about 15mm glass.
Just to clarify >..The build is ongoing and has been following guidelines gleaned from the invaluable advice gratefully received earlier on in this Topic.
Double Leaf wall construction>
Inner Wall constructed on top of a decoupled concrete slab ( i.e decoup. from Outer wall Slab)
2 layers 5/8 " Plasterboard
1" OSB
50mm # 703
12 " Air gap stuffed with 6" R38 rockwool
Gap of 5 " between the Concrete Slabs
6 " BreezeBlock Wall built upon Outer slab..Rendered on Outside..
Still trying to understand the best way to go with the doorway.. So far the plan is to have two Solid wood 'Fire" type doors ( containing Plasterboard on the inside) on both the Inner Room Wall and the Outer brick Wall, yet still unsure about if ( and how ) this area needs to keep the walls decoupled ?
What would be the best way to cover this 30 inch or so 'tunnel' from the outside wall to the inner doorway.
Also, I am completely useless when it comes to even basic equations so is there an easier way of determining the best combination of materials to be used for the dual doors.? e.g: are there Resonant frequency tables available of commonly used materials?
Thanks!!
From the sound of it AlZ seems to have some experience in building offices and meeting rooms
As such his knowledge seems to consist of the veritable handed down instruction "here's how it's done" with no understanding of the actual principles involved. This is no problem and offices and quiet rooms can continue to be built in this traditional fashion, but it must be understood that they are on an order of magnitude (in terms of material specification needed) much lower than what is required for a sound studio.Rockwall and DOUBLE plasterboard,12.5mm a sheet,either side of the rockwall are about standard if you are soundprooofing an internal wall in an office enviroment(important meeting room).
You are now confronted with one of the intrinsic compromises which sometimes have to be made in design. Best see Rod Gervais' book where he explains this construction very clearly....What would be the best way to cover this 30 inch or so 'tunnel' from the outside wall to the inner doorway.
Well, you need some way of getting fresh air into the rooms, and you also need some way of getting stale air out, so basically you need two sets of ducts. You also need an air-conditioner, to cool / dehumidify the air circulating in the rooms. You already mention the A/C unit, so I imagine that you have that figured out, but if not then take a look at the type of system called "mini-split" or just "split system". With those, the noisy part (compressor and radiator with cooling fan) goes outside, and is connected by two pipes and a power cable to the actual cooling unit inside. Look for one that is very quiet. Often in home studios, these are separate systems: the A/C cools the air, and the ducts circulate fresh/stale air. The ducts need to be larger than normal, as the key concept here is to move a lot of air very slowly, rather than a little bit of air very fast. Fast moving air makes a noise: slow-moving air does not. So you have an air intake somewhere outside, with a fan on it, that is pushing air down the duct towards your room. The duct is just some type of large tube or box, and it has to have something called "duct liner" on the inside. This is something like fiberglass insulation, and is attached to the interior walls of the ducts. This helps a lot to silence the system. Next, the duct should make at least 2 turns of 90° along the way, to help reduce sound transmission along the duct itself. Finally, the air should pass through a silencer box just as it enters the room. A silencer is just a large long box that has several baffles inside, that force the air to make several turns back and forth. The silencer and the baffles are also lined with duct-liner. Search the forum for "silencer" and you should find several designs and photos of how to make one. The most important thing to start with in the HVAC design, is to calculate how much air you need to move through the room per hour. Based on that you can determine duct sizes, fan capacity, dimensions, etc.Stuart can you please elaborate further on the ducting /ventilation system you described..
viewtopic.php?f=2&t=1929&hilit=silencer&start=74 viewtopic.php?t=8425&start=2 viewtopic.php?f=1&t=11542&start=5 viewtopic.php?f=2&t=9761&start=0 viewtopic.php?f=2&t=11485&p=89855&hilit=silencer#p89855 viewtopic.php?f=2&t=11508&p=96578&hilit=silencer#p96578 viewtopic.php?f=2&t=13821&p=97928&hilit=+silencer+ducts+might+look+#p97928 viewtopic.php?f=1&t=15378&p=110641&hilit=+duct+silencer+#p110641 Plenty more: Use the search feature of the forum. But you cannot just use the exact dimensions of those designs for your system: You have to do the calculations to make sure that your silencers have the correct dimensions for your system.If you have any links or further info for DIY silencers, ducting layout plans etc , it would be greatly appreciated.
Yep! :) viewtopic.php?f=2&t=12664&hilit=door If you have Rod Gervais book, then he covers that in good detail, and explains how to build doors that really do work, and really do follow the principles of physics. But the basic concept is mass: Lots of it. You can build that up in several layers if you want, but make sure that there are no hollow spaces inside the door (they are resonant cavities). And finally, you need at least two complete seals all around the edge of the door. It has to be air-tight when closed. Also, there must be no holes through the door, such as for handles. Rather, put a heavy-duty door-closer mechanism at the top of the door to force it closed against the seals, and just put simple pull handles on each side of the door. - Stuart -Any plans out there for construction of DIY studio doors ?
The idea is fine, but that's a pretty big gap between your slabs! :shock: Normally you only need a gap of maybe an inch or less. With that plan, you should get really good isolation. Your primary resonance is at about 10.5 Hz.! That's excellent. You should isolate the entire spectrum like that, hopefully approaching 70 dB of TL! Not bad at all!Inner Wall constructed on top of a decoupled concrete slab ( i.e decoup. from Outer wall Slab) 2 layers 5/8 " Plasterboard 1" OSB 50mm # 703 12 " Air gap stuffed with 6" R38 rockwool Gap of 5 " between the Concrete Slabs 6 " BreezeBlock Wall built upon Outer slab..Rendered on Outside..
as long as the doors are not mounted on the same frame, and there are no flanking paths or mechanical connections at all, you'll be fine.So far the plan is to have two Solid wood 'Fire" type doors ( containing Plasterboard on the inside) on both the Inner Room Wall and the Outer brick Wall, yet still unsure about if ( and how ) this area needs to keep the walls decoupled ?
One idea: Wrap panels of 703 with some type of pretty fabric, and put them along the sides and top of your "tunnel". ---What would be the best way to cover this 30 inch or so 'tunnel' from the outside wall to the inner doorway.
Exactly! Another IMM: "Internet Myth Machine" - someone who heard something somewhere, and then perpetuates the myth over the internet, but not understand the principles of why it is supposed to work, enve less the reasons why it does not work.As such his knowledge seems to consist of the veritable handed down instruction "here's how it's done" with no understanding of the actual principles involved.
Yep. Very true. And several orders of magnitude, when it comes to actual sound power. Not a clue that the difference between 35 dB of isolation and 65 dB of isolation is that the latter must absorb one thousand times more energy than the former... - Stuart -This is no problem and offices and quiet rooms can continue to be built in this traditional fashion, but it must be understood that they are on an order of magnitude (in terms of material specification needed) much lower than what is required for a sound studio.