Please direct me to the thread if this is already answered... a very basic beginner's question I think.
Really it boils down to: What's the best way to construct a 2 leaf system with the outer leaf made of brick?
I don't want the whole wall to be more than 250mm thick if possible.
I am thinking of constructing my studio like this:
outer leaf laid from brick, then render & seal it.
inner leaf 2 layers of heavy drywall with green glue.
fill the gap with RW3 rock wool.
it's the last part that confuses me, how do I fill the gap with rockwool?
if I use a stud wall in between won't that couple the two leaves together?
So do I make two stud walls, one attached to the brick wall and one to hold up the drywall, and leave a small gap between them?
if that's right, perhaps I can just make the two stud walls slightly narrower than the thickness of rockwool so that the entire gap is filled with rockwool but the stud walls don't touch?
If I'm on the right track, what's the best way to attach the stud wall to the brick wall?
And I guess the inner stud wall needs to be mounted on some rubber?
Do I just screw the drywall to the stud and then seal all the screws?
Or am I completely confused?
Brick outer leaf / drywall inner leaf.
Originally posted at johnlsayers.com, topic 21645.
First, do the calculations to ensure that it really will isolated to the level you need, at the frequencies where you need it! If you don't calculate, then you are guessing. And guessing is never a good way to build a studio.What's the best way to construct a 2 leaf system with the outer leaf made of brick?
Sounds about right, but you'll only know if you do the math! :)I am thinking of constructing my studio like this: outer leaf laid from brick, then render & seal it. inner leaf 2 layers of heavy drywall with green glue. fill the gap with RW3 rock wool.
That depends on how big your gap needs to be (between the brick surface and the inner-leaf frame). And to determine how big that gap needs to be, you have to do the math! :)how do I fill the gap with rockwool?
Yes it would, which is why you cannot do that! There are several methods for keeping the insulation in the gap, but the method that YOU will need depends on how big your gap is, and that depends on you doing the math...if I use a stud wall in between won't that couple the two leaves together?
No. You make ONE stud frame, separated from the brick wall by a gap whose size you will determine by doing the math (!), then based on that you determine which method will work for you to keep the insulation in place...So do I make two stud walls, one attached to the brick wall and one to hold up the drywall, and leave a small gap between them?
Answer: don't! That would be a total waste of wood, time and money.If I'm on the right track, what's the best way to attach the stud wall to the brick wall?
No, it doesn't. No need at all for that.And I guess the inner stud wall needs to be mounted on some rubber?
You can either screw the drywall in place, or you can nail it in place. For the first method, you will need proper drywall screws, for the second method you will need proper drywall nails. In both cases, the nails or screws for the SECOND layer must be LONGER than the standard nails/screws you used on the first layer, because those second layer fasteners need to go through the extra thickness of the first layer, and the still penetrate the correct distance into the studs.Do I just screw the drywall to the stud and then seal all the screws?
If you don't know how to hang drywall, then you should consider either taking a short course on how to do that, or hire someone to do it for you. It is NOT just simply slapping up a sheet of drywall against the studs then hammering in a few nails here and there... There are techniques and guidelines, especially for studio walls (which need to be sealed air-tight, unlike normal house walls), and you also need to know how to cut the drywall to the right size, how to mud-and-tape, and how to fix any damage that you might cause.... - Stuart -Or am I completely confused?
Thanks so much. I will definitely be hiring people, I just want to be directing them to build it the right way!
Now to search for the info on how to do the calculations I need to do.......
:thu:
- Stuart -
OK please help me do the calculation!
Or tell me where to look.... my google skills are letting me down.
Perhaps I need to buy A BOOK???
The equations for calculating total isolation of a two-leaf wall are simple:
First, for a single-leaf barrier you need the Mass Law equation:
TL = 14.5 log (M * 0.205) + 23 dB
Where: M = Surface density in kg/m2
For a two-leaf wall, you need to calculate the above for EACH leaf separately (call the results "R1" and "R2").
Then you need to know the resonant frequency of the system, using the MSM resonance equation:
f0 = C [ (m1 + m2) / (m1 x m2 x d)]^0.5
Where:
C=constant (60 if the cavity is empty, 43 if you fill it with suitable insulation)
m1=mass of first leaf (kg/m^2)
m2 mass of second leaf (kg/m^2)
d=depth of cavity (m)
Then you use the following three equations to determine the isolation that your wall will provide for each of the three frequency ranges:
R = 20log(f (m1 + m2)) - 47 ...[for the region where f < f0]
R = R1 + R2 + 20log(f x d) - 29 ...[for the region where f0 < f < f1]
R = R1 + R2 + 6 ...[for the region where f > f1]
Where:
f0 is the resonant frequency from the MSM resonant equation,
f1 is 55/d Hz
R1 and R2 are the transmission loss numbers you calculated first, using the mass law equation
And that's it! Nothing complex. Any high school student can do that. It's just simple addition, subtraction, multiplication, division, square roots, and logarithms.
:)
- Stuart -
Ah that was very very informative, thank you so much.
If I followed the instructions correctly, I worked out that for a leaf of brick / filled air gap / leaf of drywall construction:
A 100mm air gap gives me about -6dB better performance than a 50mm gap for most of the range but far better (approx 40dB!) around the 35-50Hz zone where my bass drums are likely to be.
The difference between using 2 x 12.5mm acoustic drywall vs 2 x 15mm was negligible, but going down to a single sheet of drywall was about as bad as halving the gap from 100mm to 50mm.
100mm air gap with two sheets of 12.5mm acoustic drywall seems to have the potential for -60dB around 32Hz, rising to around -83dB above 550Hz.
Obviously it won't be this good in the real world with doors, air vents, roof etc... but it seems very acceptable.
My wall would be about 240mm thick which is also acceptable.
150mm air gap takes the wall thickness up to 290mm and gives another -3dB or so which is not that impressive but makes a big difference down around 25-30Hz. I would imagine my small speakers would barely produce sound that low anyway and the loss of space is too much. I am very constrained in terms of the width of the area I can build on.
Does this all seem like it might be about right to you?
Here's an excel file I put together so you can quickly type in variables and it will show you your isolation values at different frequencies.
Hopefully it speeds up your calculation process:
http://www.mediafire.com/file/shl5c966q ... .xlsx/file
Greg
Thanks.
By the way, I've included the width of the stud wall as part of my air gap, is that correct?
The "air gap" in the equations is the distance across the full cavity inside your wall, between the leaves. Distance from the face of the brick, that faces the cavity, up to the face of the drywall that faces the cavity. That's the "depth" of the cavity, and that's what matters for the MSM calculations. Your conclusions in your previous post are very correct (6 dB difference for halving the air gap or halving the mass on one leaf, etc.), but your overall isolation numbers seem a bit high: "100mm air gap with two sheets of 12.5mm acoustic drywall seems to have the potential for -60dB around 32Hz, rising to around -83dB above 550Hz.". What density are you using for the brick wall, and for the drywall?By the way, I've included the width of the stud wall as part of my air gap, is that correct?
Yep!150mm air gap takes the wall thickness up to 290mm and gives another -3dB or so which is not that impressive but makes a big difference down around 25-30Hz.
Don't "imagine"! Don't "guess"! Find out for sure. Check the manuals or on-line specs for your speakers, to find out how much energy it is putting out down that low. And check that against your music needs! For example, if you track and mix a lot of 6-string bass, and don't have good isolation below 50 Hz, then you have a problem. Ditto if you mix 6-string bass and your speakers don't put out much sound below 50 Hz... Always match your speakers to the task at hand, and to the room, then match the isolation to that. - Stuart -I would imagine my small speakers would barely produce sound that low anyway
Bricks seem to be about 1800kg/m3.
They are 92mm thick.
I think that gives me about 160 kg/m2.
I was looking at Gyproc acoustic plasterboard which is quoted as being 10.6 kg/m2, so I presume if I am using two layers I can just double the figure to 21.2 kg/m2.
TL of brick = 45
TL of 2 layers of Gyproc = 32.25
For a 10mm air gap, f0 = 31Hz
f1 = 550Hz
My next question is:
the rockwool will be inside the gaps in a studwall to which the drywall is screwed. If the rockwool is thicker than the stud, so the stud is away from the brick wall, does it matter if the rockwool touches the brick? ie. Should I fill the ENTIRE gap or leave a small gap of actual air?
I'm not seeing that. Here's the rough calculations: f0 = C [ (m1 + m2) / (m1 x m2 x d)]^0.5 = 43 ((160+21) / (160*21*0.1)) ^0.5 = 43 (181 / (336)) ^0.5 = 43 (0.54) ^0.5 = 43 x 30.74 = 32 Hz R = 20log(f (m1 + m2)) - 47 = 20log(32 (160 + 21)) - 47 = 20log(32 (181)) - 47 = 20log(5792) - 47 = 20 (3.76) - 47 = 75 - 47 = 28 dB So your isolation at resonance is about 28 dB, and certainly not 60 dB. I'm not sure how you got 60 dB there. - Stuart -100mm air gap with two sheets of 12.5mm acoustic drywall seems to have the potential for -60dB around 32Hz, rising to around -83dB above 550Hz.
Right. I got the same results as you from the calculation.
The thing that the formulae you gave doesn't tell me is:
What is happening in the transitions between the frequency ranges covered by the 3 equations?
ie. just above the resonant frequency.
For example at 40 Hz, R is given as 30dB by the first equation, and 60dB by the second equation.
F0 is about 31 Hz so therefore 40>f0 and we use the second of the three equations to find R=60, but I suspect there is something more subtle going on near the resonances.
I wonder what the real R is for 40Hz, or 35Hz or 32Hz?
On the positive side we are going to survey the site tomorrow and figure out how much space there is and this will tell me exactly how thick the walls can be. If i had infinite space I would make the air gap a metre thick but it's a narrow plot unfortunately!
I've been running the calculation using the spreadsheet ( so useful - thanks!) on various possibilities in my place. I was planning on floating an inner stud wall in a 30' x 20' brick room.
I have a mix of solid brick and cavity walls in my building (an Edwardian edifice - built in 1910 with many alterations over the years) My bricks have a surface density of around 225Kg/m2 per wythe and I will probably use a sheet material of around 15Kg/m2 for the second leaf.
With a 4.5" gap and insulation in the gap, the resonant frequency of the wall system is around 34hz. Below this frequency the TL drops by half from around 61 db to around 31db. This does seem extreme, and it would seem that only the kick drum range would be an issue..
This all seems very adequate for my purposes, but I suspect other issues will have a bigger effect than the wall gap. How can one ascertain the point where increasing the air gap or 2nd leaf density will be compromised by other considerations?
How does one account for flanking transmission when looking at the design of such a wall?
In my case I also have windows that are 8' x 4'. I suspect those will have a bigger effect on my max TL in the room than the wall structure.
As an aside, I wonder whether floating the inner stud wall is even worthwhile - I could put studding directly onto the brick much more easily - and the cost of floating the wall versus the extra TL is hard to calculate in this case.
Any thoughts?
Welcome Leland2 (whatever your real name is)!
With as much detail as you provided, I'd suggest making your own thread on the design forum. From there, keeping all of your questions to one thread will allow everyone to follow all of your build details from the beginning to the end.
I'm glad my spreadsheet is making your life easier!I've been running the calculation using the spreadsheet ( so useful - thanks!)
What benefit do you think floating your walls will provide? In order to properly do this, you'd need to know the exact weight of your walls (and everything mounted to them such as acoustic treatment) as well as the ceiling. Then you'd have to use the correct material with the correct deflection to isolate your walls at as low of frequency as possible, all while maintaining structural integrity. If your isolation level requires to go to the lengths of floating walls, you're best bet is to float your whole inner leaf room, floor and all. That = insane money and design. If you're on ground level, Earth is the best to build on and you won't need to float anything except your speakers when soffit mounting.I was planning on floating an inner stud wall in a 30' x 20' brick room.
What material is this?I will probably use a sheet material of around 15Kg/m2 for the second leaf.
Mass and the gap (filled with appropriate insulation) are the two factors we can adjust. The only other factor after those would be attention to detail during the build. Don't skimp anywhere. Make sure the mass is maintained EVERYWHERE -- including windows, doors, electrical penetrations and HVAC silencer boxes!but I suspect other issues will have a bigger effect than the wall gap.
Point in which factor? The spreadsheet will allow you to easily type in smaller or larger gaps and see if adding that extra half an inch would be worth it. There is a point where adding extra gap yields very little transmission loss increase. So, balance out leaf mass and gap. Some people have huge spaces that are able and willing to have 2 foot gaps. Most people are desperate to keep 1/2". Where we are desperate for space, we often have to spend more money on things like MLV or a ton of Green Glue compound. And regarding becoming compromised, that would only happen with attention to detail during the build as mentioned above.How can one ascertain the point where increasing the air gap or 2nd leaf density will be compromised by other considerations?
Again, flanking would almost certainly occur when trying to float your wall and ceiling assembly. You can (for a ton of money) avoid flanking by floating your entire inner room on a very heavy concrete slab. The best solution is to just anchor your walls to your floor.How does one account for flanking transmission when looking at the design of such a wall?
Your windows can be as large as you want. Just use proper windows. Each leaf must maintain the same surface density as your wall. Typically if your window is a 1/3rd the thickness as your drywall, you're good to go in terms of mass. Make sure you use laminated glass. Preferably built with acoustic PVB, not regular PVB (this is a luxury and will increase performance, but regular PVB works well too).In my case I also have windows that are 8' x 4'. I suspect those will have a bigger effect on my max TL in the room than the wall structure.
As I've written above, it is not worth floating unless you need upwards of 100dB of isolation.I wonder whether floating the inner stud wall is even worthwhile.
No. You don't want to anchor your studs to your brick outer leaf! Leave the gap and make sure your ceiling for your inner leaf is sitting on your inner leaf walls and not touching the outer leaf anywhere!I could put studding directly onto the brick much more easily
Probably not. Tens or hundreds of thousands (depending on your room size) probably isn't worth it. Again, I'll remind you to start a design thread where we can follow your design come to fruition! Gregand the cost of floating the wall versus the extra TL is hard to calculate in this case
Hi there "Leland2", and Welcome! :)
It would be better for you to start your own thread about your build, rather than post questions on somebody else's thread.
How are you planning to float your wall? Floating a wall is just as complex as floating a floor, and you very likely do not need to do either.I was planning on floating an inner stud wall
Ummmm... there's something very wrong with the way you are doing your calculations. Below MSM resonance, TL should rise again, as the stiffness of the wall becomes the dominant factor. And I can't see how you could get a change of over 30 dB in the space of just half an octave! Plus, I very much doubt that you would get 61 dB of isolation at 34 Hz. Something doesn't add up here... I suspect that there's something wrong with your calculations, or the way you did them...Below this frequency the TL drops by half from around 61 db to around 31db
What type of kick drum are you using that has a fundamental round 34 Hz? :shock: That's some kick!This does seem extreme, and it would seem that only the kick drum range would be an issue..
If your wall system will have an MSM frequency of 34 Hz, then it won't isolate at all below 48 Hz, and only isolates decently above about 70 Hz. Are you sure that's OK?This all seems very adequate for my purposes,
That depends on what "other considerations" you are talking about! For example, if you are talking about failing to seal the cracks around the edge of the wall properly, that would cost you a large chunk of your isolation, regardless of how big the air gap is.How can one ascertain the point where increasing the air gap or 2nd leaf density will be compromised by other considerations?
That's easy! Don't allow any flanking! :) Assuming that you are building on a nice firm solid concrete slab-on-grade, and that you take care to ensure that no part of the inner leaf touches any part of the outer leaf, then flanking is not an issue.How does one account for flanking transmission when looking at the design of such a wall?
Then you will need to do the math for that too! You will have one sheet of glass in the outer leaf, and another sheet of glass in the inner leaf. Do the math to make sure that the MSM frequency and isolation will be the same for that part of the wall, as it will be for the rest. If not, increase the mass of the glass, or the size of the air gap.In my case I also have windows that are 8' x 4'. I suspect those will have a bigger effect on my max TL in the room than the wall structure.
As I mentioned above: trying to float a wall is just as hard as trying to float a floor. Here's why: viewtopic.php?f=2&t=8173 The exact same applies to walls.As an aside, I wonder whether floating the inner stud wall is even worthwhile
I don't understand what you are trying to say there: If you attach your inner-leaf studs directly to the outer-leaf wall, then the entire wall is flanking, and you have a fully coupled 2-leaf system, which isolates like crap! (excuse my French). It's pretty easy to calculate the isolation of that: use mass law alone, as though it were just one leaf. And I don't understand what this has to do with floating your wall: if you attach it to the brick, then why would you want to float it? And if you DON'T attach it to the brick, then floating it is probably not going to do any good, for the reasons outline in that link. Firstly, how would you float it? I assume you mean on some type of rubber pads. If so, how would you make sure that you get the correct deflection for that type of rubber, along the full length of the wall? Can you be sure that the deletion will be constant, and not be either too great or too small at some points, which would negate the floating completely, and leave the wall coupled to the floor again. Etc. It's far better to just have your wall resting directly on the floor, without attempting to float it. As long as your floor slab is suitable, this is the best method for isolating a room. Make sure it is properly decoupled (not touching the existing outer-leaf walls, or the outer leaf ceiling), with enough mass on it and enough air gap, and you will be fine. Floating a wall is not necessary unless you have very extreme isolation requirements: Decoupling is all you need. The cost can be calculated, but I don't think you'll like the answer: as Greg pointed out, floating a wall is an expensive thing to do, and complex as well. Floating the entire room makes more sense, but is VEEEERRRRYYY expensive, and even harder to do. Take a close look at that thread that I linked you to above: it's about floating a floor, but the exact same concepts and principles apply to floating a wall. I would not recommend that: just decouple your inner-leaf from your outer-leaf, check that you have enough mass and air gap to get the frequency and isolation you need, then you should be fine. - Stuart -I could put studding directly onto the brick much more easily - and the cost of floating the wall versus the extra TL is hard to calculate in this case.
I can see I need to be more cogent! I do not intend to hijack - I was mostly interested in the brick/studding combination and the calculations for TL thereof.
When I said float the walls, I actually meant decoupling in the vertical plane - ie they float in front of the extant walls. My apologies. For my situation, I have already established that floating the walls in the horizontal plane (the floor/ceiling) would be expensive and also pointless given limits caused by other conditions in the building. Hence my interest in flanking conditions - if the wall is in contact with the outer floor and ceiling, how much will one benefit from decoupling the walls in the vertical plane only? Obviously, the floor/ceiling construction method and materials would be pertinent to that conversation.
The figures I quoted came from inputing my specific values into the spreadsheet provided - I must say I was surprised myself as it didn't really match my empirical experience. Hence my conclusion that other factors must come into play. Perhaps I'm misinterpreting the figures. (My inputs - leaf 1: 225kg/m2 - leaf 2: 15kg/m2 - and a 4.5" gap)
I'd be interested to know the source of the equations - can anyone provide a reference?
As an aside - as I did not want to hijack the thread:
The sheet material I mentioned is called Versapanel - a form of concrete particle board. It is much more expensive than plasterboard, but has the benefit of being moisture resistant and reusable. There are specific problems using plasterboard in this building - I've already had to remove something like 3000 ft2 of it. And it is very hard to dispose of here - it is classed as a toxic waste and requires specialised recycling which is expensive and difficult to access.
My reference to the windows as a limiting factor for TL is that doors and windows are traditionally a weak point for TL. There is little point in having amazing wall construction if the weak point negates all that effort. Extant 8'x4' wooden framed casement windows are not exactly high efficiency when it comes to TL, even if I put 12mm laminate glass as a secondary glazing in the inner wall of the room.
FYI, this is not a new building - it is an Edwardian age building in the UK not built to anything like modern standards. It has specific problems for which the solutions in its repair and conversion are very different to standard solutions for modern buildings . If I was going for supreme isolation, I suspect the only solution is knocking the whole thing down and starting again, which is not possible! Having said that, I'm sure I can get its isolation to a better level than it is currently!
I will in due course start my own design thread. It wasn't my intention to hijack!
Right. When discussing technical subjects, it's better to use the correct technical terms, rather than colloquial terms.I can see I need to be more cogent!
Technically, that is "decoupling", not "floating". Floating, as the name implies, is raising something up vertically so it is no longer in contact with the ground below, just like water floats a boat. When you separate things away from each other horizontally, you are not floating: you are decoupling.When I said float the walls, I actually meant decoupling in the vertical plane - ie they float in front of the extant walls.
The limitations of the bilding is not the only reason whey it would be pointless and expensive: here are the other reasons why floating a wall or floor would be expensive and pointless: viewtopic.php?f=2&t=8173 .I have already established that floating the walls in the horizontal plane (the floor/ceiling) would be expensive and also pointless given limits caused by other conditions in the building.
Let's rephrase that in the technical terms, so that we are all on the same page, then I'll answer: If the inner-leaf wall is in contact with the outer-leaf floor and ceiling, then how much benefit do you get from decoupling the inner-leaf wall from the outer-leaf wall". That's the question you are actually asking. First, the inner-leaf wall should NOT be in contact with the outer-leaf ceiling! It should only ever be in contact with the floor, since you are not going to float your floor, for all of the good, valid, and correct reasons we already mentioned. So your inner-leaf wall will be resting on the concrete slab, just like the outer leaf wall will be, and that is the ONLY point of contact. The flanking limit for a situation like this is somewhere around 60 to 70 dB, depending on a few factors, but assuming you have a fairly massive concrete slab-on-grade, then closer to 70. Of course, it's highly unlikely that you can get 70 dB isolation for the rest of the structure, and therefore the flanking through the slab is not an issue. You'll never get to that limiting level, so it's a moot point. However, if you connect your inner-leaf wall tops to the outer-leaf ceiling, then you place a much lower limit on total isolation, since your wall is now flanking at BOTH ends (top and bottom), and is now fully restrained in 2 dimensions: it can no longer vibrate freely at the top, restrained only by the floor. There's a lot more factors to take into account here, but your isolation limit is probably around 60 dB now, absolute best case, and probably more like 50. But if you attach your inner-leaf wall directly to your outer leaf wall, you have basically trashed any chance of having good isolation. The inner-leaf is now fully restrained in all dimensions, and any vibration on that leaf is directly transmitted to the outer-leaf, this placing a very low limit on isolation. This is now a fully-coupled system, so isolation is minimal. Maybe 40 dB limit, best case, and probably not much more than 35 or so in the real world. A typical house wall gets maybe 30 dB, so not much better than that. In addition, since the air gap is now small, there's the real possibility that the MSM resonance will be fairly high, thus placing a further limit on isolation.if the wall is in contact with the outer floor and ceiling, how much will one benefit from decoupling the walls in the vertical plane only?
From my calculations, that would get you around 52 dB isolation, theoretically, if you do everything right. HOWEVER! It would not be good for low frequencies. The MSM resonant frequency of that system (asssuming you fill the cavity with suitable insulation) would be around 35 Hz, which means the wall does NOT isolate below 48 Hz, and only isolates reasonably starting at 70 Hz, with good isolation above 104 Hz. So, that's not much good if you plan to have drums, bass, electric guitar, keyboards and things like that. I would suggest that you increase the air gap, and increase the mass on the inner-leaf. Double your mass, increase the air gap to 6", and you'll be getting more like 60 dB isolation, MSM f0 will be around 21 Hz, isolation starts at 30 Hz, is good at 42 Hz, and great at 64 Hz. Of course, all of the above assumes you will fully decouple your walls, except from the slab.My inputs - leaf 1: 225kg/m2 - leaf 2: 15kg/m2 - and a 4.5" gap
Sort-of true. But not necessarily. Doors and windows are only weak points because of the seals: if your windows are non-operable (fixed in place, and cannot be opened), sealed very well, then the exact same equations apply to those as to the rest of the wall. So it is merely a matter of choosing the right glass and air gap in order to achieve the isolation that you need. It's not complicated.My reference to the windows as a limiting factor for TL is that doors and windows are traditionally a weak point for TL.
True, which is why it is so important to seal EVERYTHING perfectly air tight. Including the surface of your brick wall. Brick is porous, unlike glass, so it is entirely possible that unsealed brick could be a bigger detriment to isolation than a properly sealed window. Seal it with any good quality masonry sealant, before you start on the inner leaf. Air-tight seals are critical.There is little point in having amazing wall construction if the weak point negates all that effort.
The are exactly as efficient as their surface density (assuming that the frames are in good shape, non-operable, and properly sealed. If the surface density is too low, then replace the glass with higher density stuff, such that the MSM f0 is hte same as for the rest of the wall.Extant 8'x4' wooden framed casement windows are not exactly high efficiency when it comes to TL,
12mm is rather thin for your situation. I haven't done the math but I would guesstimate that you'd need something like 22mm on the outer leaf, and 16mm on the inner leaf, with an air gap of maybe 7" at least, to be able to get close to matching the rest of the wall.even if I put 12mm laminate glass as a secondary glazing in the inner wall of the room.
You didn't mention that yet, and it is the single most important number of your entire design: What is your isolation goal, in decibels? How much isolation do you actually need? Without knowing that, then all of the above is just academic chit-chat, and meaningless to your design. The entire design is based on isolation. That dictates many other aspects of the build, in a sort of "domino effect", way down the line, even in areas you wouldn't really think are related. But the are.If I was going for supreme isolation,
Sure, but what IS that level? It's the key to your entire design... - Stuart -I'm sure I can get its isolation to a better level than it is currently!