Double Garage Control Room Build UK

[cmp]

Hi, new poster here. I have been doing a lot of research over the last few months, using the fantastic resources that exist here and that you point to on this site (Rod Gervais’ book etc). Wow, quite a learning curve! I have soaked up what I can, but I still have some very grey areas, that I could use some expert help with.

I have been making records for a long time, as a producer and mixer. Rightly or wrongly, I have generally tended to focus on what I am doing on the session, rather than getting too bogged down in the specific atomic technicalities of why, so, despite my experience of recording/mixing, I’ve managed to remain pretty clueless about the real details of acoustics and treatment ☺. I’ve seen and worked in a lot of control rooms and live rooms, some great, some terrible and perhaps this is where my measured suspicion of the art of acoustics takes root. I have worked in some fantastic sounding control rooms that have not cost the earth (large and very small) and also some very bad ones that have cost an absolute fortune and I have sometimes struggled to find much of a correlation between budget and result.

In the past I have also “owned” a few studios – ranging from some properly pre-built rooms to some very simple set-ups in the house, all with varying results. We have just moved house and I am looking to build a new studio that I can use for overdubs and, for the first time at home, mixing. I have an existing building to use – a reasonably sized detached double garage with an upstairs room, accessed by an external staircase. The walls are constructed with concrete blocks and rough-cast rendered on the outside and painted on the inside – a total thickness of 237mm.
The downstairs (garage part) is one open space 5.97m x 5.97m x 2.25m (I’m guessing that’s where the problems start, right?) and I am currently seeing that as a reasonable sized control room, for mixing, editing, programming, keyboards, where I spend most of my life. The floor is a proper concrete slab which has been tiled. The ceiling downstairs is currently 12mm plasterboard screwed onto 8x2 joists. Two annoying windows - at least one will be removed and the void filled with concrete blocks. Double wooden garage doors, which will be fixed in place and a new concrete block wall built inside.
The upstairs is an eaves room 5.97m x 3.68m x 2.24m (highest), with a dormer window, which I am considering as vocal booth/acoustic guitar/amp room (and I’m guessing that’s where the problems continue!). The floor is 18mm chip-board, with underlay and carpet. The walls and ceiling are all 12mm plasterboard, insulated, but with what, I have no clue.
The wiring looks like it has been carefully done and is pretty extensive for a garage. It has its own supply and consumer unit and runs right around both floors with a lot of double outlets. Without testing, it looks like it might just need some careful extending into the inner room. I have an electrician coming to look at that.

I am very fortunate to have a good friend that is a carpenter who has extensive experience over 15 years of building studios and mastering rooms, who is going to do the build with me. So the actual build should be ok, but I definitely need some help with the design and the specifics of the isolation and the treatment.

Apart from the dimensions of the control room and the awkwardness of the reflections and isolation in the eaves room, I have 2 other quite major issues that will make you laugh – budget and timing. There will be more budget available in the future to make adjustments and improvements, but for now, I need to get something up and running for around £10-15k. And, just to add a bit of extra stress, I need to try my absolute hardest to get it done in the next 2 months or so.

In terms of what sort of level I mix at, I have no idea - I have ordered a meter and that information will follow on, but as a quick rule of thumb, I use Genelec 1031As and have always considered that their “overload” light is there to tell you when it sounds just about loud enough ☺. People always tell me its very loud! I am probably going to incorporate some sort of switchable sub into the room as well, to run with the Genelecs for a bit of extra BS factor during overdubs. I generally have one other default mixing level, which is “mice-volume” on the NS10Ms.

I am thinking of using John’s design for “Control Room” as a starting point, and in a lot of ways it will be much like Azzur's build. I realize the dimensions I have are by no means ideal, but they are what they are, so I have to somehow deal with it – especially the lack of ceiling height. For simplicity and budget's sake, I am just considering the downstairs room for the moment.

A few questions to start if I may?

a) Wall Construction – from outside to in, what is the best possible combination for me to use?

I am considering modifying John’s suggestion of:

Existing Concrete Block
Gap - what size?
50mm insulation
2 layers 16mm plasterboard - would a 3rd layer of 12mm or 18mm mdf sandwiched in the middle improve this much?
Stud (suggested size was 75mm x 35mm, but if I use 100mm, is that a problem?)
Insulation between studs 100mm
Treatment and finish.

Does that work? Or am I throwing more materials at the problem than is necessary, for not much real gain?

The other option is a staggered double stud with 3 sheets on the outside of each stud and insulation between. Does this constitute a triple leaf wall with the concrete block? Or does the concrete block not count as a leaf if it is standing on its own? I have searched, but I could not quite untangle that information.


b) My builder is suggesting that instead of building a concrete block wall across the garage doors, we fix sheets of 18mm ply to both sides of a 4x2 stud frame and fill it with kiln dried sand. I am in the process of working out the mass figures, but there might be something in the theory that the additional mass might be a good starting point for the back of the room. Any thoughts on this?

c) Ceiling. Resilient hangers or channel on the existing joists (I know), supporting 2 sheets of 16mm plasterboard and probably another layer of 15mm ply on the floor above. 100mm insulation in the original void. Is this going to provide enough isolation? – it feels a little like the weak point of the build, but I am hamstrung by the ceiling height.

d) Floor. I have to be a little careful here as I am trying to keep the ceiling height to an absolute maximum, bearing in mind it is already low and I will doubtless end up with some sort of cloud configuration up there. Given that the tiled slab is dry and flat, do I actually need to build a stud floor on top? Or can I use some sort of dpm, acoustic underlay and go straight to a layer of ply and a combination of laminate and carpet tiles or similar?

Thanks in advance for any help – you do a really great job here of assisting people through this whole minefield of science and vagueness!

Oh yeah, I forgot the HVAC haha… It’s England, it’s always cold and raining right? I guess I need to look into this…

Design will follow in a week or so.

p.s. I've attached some pictures and the worst sketchup drawing you will ever see, but it took me half the afternoon, so I'm including it! Think I might stick to some hand drawn and scanned plans from now on, haha!

[Soundman2020]

Hi there "CMP", and welcome to the forum!

Wow, quite a learning curve!

Very true. And the good news, it gets steeper as you progress along it, until it's practically vertical and unassailable ... Naah, it ain't that bad, but it does seem like it at times! And it does level out a bit, eventually, to the point where any 4x4 can handle it... with a winch, chains, and a military armored troop carrier to help it along!

I’ve seen and worked in a lot of control rooms and live rooms, some great, some terrible and perhaps this is where my measured suspicion of the art of acoustics takes root. I have worked in some fantastic sounding control rooms that have not cost the earth (large and very small) and also some very bad ones that have cost an absolute fortune and I have sometimes struggled to find much of a correlation between budget and result.

If it is of any comfort, I've been hired on a couple of occasions to fix big-money rooms such as the ones you describe, and I know John has too. I'm talking about rooms that were designed by big-name studio designers, and had large price tags attached, but where the owners were far from happy with the outcome. I won't be mentioning names, but it's surprising that designs where lots of dollars were spent could turn out so bad, when they clearly and obviously defy the laws of physics, or the brief of the owner. I know John has also fixed rooms like this, since we have discussed it off-line on a couple of occasions, sort of sharing "horror stories" about big-name, big-money studios that fell flat, acoustically. I'm not exactly in that league of designers (although John certainly is!), but I do know enough to see some really silly things done in those "big" studios, and I'm left wondering.... Why on earth would they do that? And it's also somewhat of an ego boost as well as simultaneously humbling, when a customer who just fell out with a big-name designer comes to me and asks me to fix it. Case in point: I'm just putting the final touches to a mastering studio design for a customer "somewhere in the USA", who was in this situation: originally he paid big money to have a well-known designer draw up detailed plans for his place... but it would never have worked! I tried to re-work his plans, but we ended up re-designing the whole thing from scratch.

I'm not sure which "high end" studios you have been in that didn't impress you, but I'm not surprised: it happens!

On the other hand, there sure are a lot of not-so-high-end studios, done on a tight budget, that turn out really well. You'll find quite a few of those, right here on the forum! And a whole bunch more on John's own web site. Many, many, many. I'm sure that's why you are here! Because you see results, not hype.

OK, so what's the difference? How is it that some "pro" studios end up pretty bad, while many "amateur" studios end up darn great? The only answer that makes sense to me, and that jibes with my own experience, is that the folks who succeed are the ones who take the science of acoustics seriously, and build rooms that logically follow the laws and limitations of how sound actually behaves. Rather than aiming for some bold architectural statement, or going after amazing look, artistic-decoration, or personal biases in some sense. In other words, knowledge beats ignorance. Every time. When you follow the laws of physics and design using them, the result just works. When you try to cut corners, re-invent the wheel, or go with esoteric weirdness, it doesn't work.

There's two approaches here to getting a great studio, that work. One is John's approach: empirical experience. John has been around so many studios for so many decades, in so many places, that he just innately "gets it", and understands exactly what a given space needs to make it work. I do not have his vast experience, so I spend a lot more time working through the math and the the theory, as well as studying what he did and figuring out WHY it works, so I can apply it in other places. You'll notice that a lot of my designs are inspired by John's designs, because I see how and why they work, and how I can adapt them to other rooms. I don't try to copy John, but I sure do try to learn from him, and follow him! Don't get me wrong: I'm not saying that John does not use math and science in designing his rooms: he certainly does! And I'm not saying that I don't use personal empirical experience in designing: I certainly do! It's more along the lines that John already walked the path of science, math and acoustics, years ago, and now understands sound and acoustics so well that he doesn't need to rely on calculating every last thin, like I still do.

Both approaches work: knowledge, and science.

But the approach that does NOT work, is "winging it on a whim", thinking that it if looks good it will sound good, attempting to do things that are acoustically silly. I have no idea why some big-name studios were designed like that, but you've seen it yourself. The look nice but sound ugly.... It's not that the science of acoustics is flawed; it's that some people just don't use it!

Anyway, I'll stop waffling now, and get down to YOUR studio! The point of the waffle was to encourage you that your place really can be one of the "great acoustics on a low budget", provided that you follow one of the two paths above: And since you already admitted that you haven't paid a lot of attention to the empirical side of acoustics (figuring out why some rooms are good and others are bad, despite the budget), to get to your goal you'll probably need to take the other track: theory, math, science, research, study...

The walls are constructed with concrete blocks and rough-cast rendered on the outside and painted on the inside – a total thickness of 237mm.

That's an excellent start! Really good. One of the first things about isolation (which you probably already know) is that it requires mass. Lots of it. The more mass you have, the better your isolation will be. Concrete has mass. Render has mass. And 237mm of concrete+render is a nice sized chunk of mass.

You have probably also learned that isolation requires that the "mass" must be sealed air-tight, for the very simple reason that "if air can get through, then so can sound", which in turn is based on the even simpler concept that, at it's most basic definition, "sound" is just "vibrations moving through air". So no air gaps in your wall. Most types of render are pretty good at sealing air gaps, and your wall is rendered on both sides, which bodes well. If you really want to go for high isolation at low cost, then you could paint that wall with something that will even seal the pores in the render, before you move on to building your inner-leaf wall. The pores can play havoc with the isolation, as they do allow the air (and thus the "vibration of the air") to penetrate into the wall surface. Sealing prevents that. Masonry sealer would be good, or even a cheap wall primer. It doesn't have to look pretty, since it will never be seen, so just slap on a good layer of anything that will seal the surface. If you look around the forum, there's a couple of cases where members have followed this advice, and immediately commented on how different the room sounds from just having the porous surface sealed.

The downstairs (garage part) is one open space 5.97m x 5.97m x 2.25m (I’m guessing that’s where the problems start, right?)

Yep! For two reasons:

1) It is square. which is about the worst possible shape, acoustically, as all the modal resonances in the "length" direction will occur at the exact same frequencies as the modal resonances in the "width" direction, so you'll have some very large modal issues at just a few very specific frequencies, with very large gaps in the low-end spectrum in between them... Not a good situation, so you'll need to look into the theory of room ratios, modal spread, room, modes, ratio calculators, etc. You will have to make sure that your inner-leaf room fixes this problem, by NOT having the same dimensions, nor dimensions that come with about 5% of being the same, or being a direct multiple of each other. Use one of these Room Ratio calculators to figure out the best dimensions for your room:

http://www.bobgolds.com/Mode/RoomModes.htm

http://amroc.andymel.eu/

Both of those are very good, and will help you to decide how best to build your room. They give you tons of information that is really useful to help figure out the best dimensions.

2) Low ceiling.Sound likes space, and it likes space in all directions. You do have nice space horizontally, but sound also likes space vertically. Sound is 3D, not 2D, and sometimes people tend to forget that in their room designs. And you have precious little space in the vertical direction, so you will have to take very special, extra-great care to lose as little of that as possible when you put up your inner-leaf ceiling. I would suggest giving vary careful consideration to using John's famous "inside out" concept for your inner-leaf ceiling. It has man advantages, one of which is allowing you to keep as much acoustic height as is physically possible. Another is that it automatically provides lots of diffusion at low frequencies, and also provides space where you can have plenty of treatment, that helps to "raise" the ceiling, acoustically, so that it seems higher than it is, psycho-acoustically.

and I am currently seeing that as a reasonable sized control room, for mixing, editing, programming, keyboards, where I spend most of my life.

Yes, but it's not really because you "see" that! It's because it really is like that...

There's a document from the ITU called BS.1116-3 that lays out the specifications for "critical listening rooms", which obviously is exactly what a control room really is! It's a place where you can listen critically to your mixes, and make judgement that turn out to work really well, because it is an acoustically neutral space. That's the key goal for a control room: it must be absolutely neutral, acoustically. It must not add any "coloration" to the sound coming from the speakers, and it must not subtract anything from that sound. The room must simply transmit that faithfully and truthfully and cleanly from the speakers to your ears, as you are seated at the mix position. It seems like it is simple, but it's a LOT harder to achieve than it sounds. Here's what it looks like when it is properly done: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471 The acoustic response in that room is truly "neutral". What you hear at the mix position is exactly what came out the speakers, not a single dB more or less, in any sense. That's your goal.

Now, achieving that depends on a number of parameters, commencing with the size of the room. BS.1116-3 is based on years of research by leading acousticians, and the conclusion is simple: You need a floor area of at least 20m2 in order to be able to hit the goal of "acoustic neutrality" easily. You can go a bit smaller, yes, but then it becomes harder to hit the goal, and the room will need more treatment, making it more complex and more expensive. You might be able to get by at 18m2, and right now I'm working on treatment design for a room that is just 16m2, purely for the challenge of seeing just how far I can push it, but I would certainly not want to go smaller than that. The smaller the room is, the more complex it gets acoustically, since the modal issues just become so severe, as does the acoustic loading of the speakers (the way the room itself changes the way the speaker cones can move), and that affects the entire response of the room. Small rooms are really, really tough, and need tons of treatment.

Your room looks good, but close to the edge. You have a bit more than 35m2 to play with, but that's your OUTER-leaf dimensions: you still need to build the INNER-leaf, and that's what those dimensions are about: The hard, rigid, massive internal surfaces of the inner-leaf room. The walls and air gap take up quite a bit of space.

So your next priority is to lose as little floor area as possible, ideally keeping it well above 20m2, but also taking into account that you WILL lose at lot of area due to the need to isolate, and you WILL need to reduce the room width to fix the modal issues.... so this is where you need to learn how to juggle! You have to keep a lot of balls in the air as you fiddle and twiddle and tweak, to maximize both space and modal response and isolation and building materials and budget and internal acoustics...

The floor is a proper concrete slab which has been tiled.

Excellent! Your floor is done already! Nothing more to do there.

The ceiling downstairs is currently 12mm plasterboard screwed onto 8x2 joists.

The drywall (plasterboard) will come off, of course, but seeing as you are on a tight budget, take it off carefully and save it: you can re-use it later, for adding mass to places where it will be needed.

Two annoying windows - at least one will be removed and the void filled with concrete blocks.

It is possible to keep windows, if you like them, and if they are in places that won't interfere with treatment. But if you don't want them, then by all means get rid of them! And bricking up the gap is a great solution. Use the same materials and techniques as for the rest of the wall, if possible, such that your surface density remains consistent across the entire wall. Isolation is only as good as the weakest part, so keeping mass consistent and constant around the entire "leaf" is important.

Double wooden garage doors, which will be fixed in place and a new concrete block wall built inside.

Yup! Smart move

The upstairs is an eaves room 5.97m x 3.68m x 2.24m (highest), with a dormer window, which I am considering as vocal booth/acoustic guitar/amp room (and I’m guessing that’s where the problems continue!).

Yup! For sure! Big-time...

The floor is 18mm chip-board, with underlay and carpet

The underlay and carpet can go: no use to anyone. The 18mm chipboard is a pretty lousy base for your upper rooms, and you will DEFINITELY need to beef that up with substantial extra mass. However, you are going to need to hire a structural engineer for this part, since you need to know how much extra mass you can add to those skinny 2x8 joists that are going to be supporting your upper-rooms. Those joists are not very big, and they are spanning at nearly 6m, so there's not a lot of live load or dead load available here. Those things need to support not just the floor, people, gear, and equipment, but also your entire inner-leaf rooms! That's a lot of mass to shove on top of a few 2x8s. I have a feeling you'll need to beef those up as well: maybe sistering each one with a second 2x8 right next to it, screwed and glued, or bolted, would likely do the trick. But you'll need a structural engineer to tell you if that is acceptable under your local building code, and how to do it, and what the final load-carrying capacity will be.

The walls and ceiling are all 12mm plasterboard, insulated, but with what, I have no clue.

You'll find out when you take off the drywall, which you WILL need to do, in order to create the isolation system that will give you the isolation you need for the use you are planning...

Without testing, it looks like it might just need some careful extending into the inner room. I have an electrician coming to look at that.

Unfortunately, that isn't really an option. The reason, once again, is simple: You cannot allow multiple large holes in your isolation system. Each hole is a major weak point. Yeah, you COULD try to build massive boxes around each hole, and seal them all air tight, and hope for the best... but that's a lot of complication, expense, and potential points of failure in the future. The general rule in studios is that you can allow just one very small penetration through the wall, to bring in your electrical power feed, and then distribute it internally, inside the room, using surface-mount electrical systems. A lot simpler, a lot more flexible, and only one single weak point. That single penetration needs to be handled in a specific manner too, in order to minimize the potential loss of isolation.

I am very fortunate to have a good friend that is a carpenter who has extensive experience over 15 years of building studios and mastering rooms, who is going to do the build with me.

Excellent! Then you have a major positive on your side. Finding someone with studio experience is indeed very good news. He's already aware of all the unusual techniques and tricks that he needs to know, in order to do this right. I'm just hoping that he's the guy that worked on the GOOD studios you mentioned, not the BAD ones!

I have 2 other quite major issues that will make you laugh – budget and timing.

Welcome! You finally made it! You are now a confirmed member of the Insane Studio Builders Guild! And this forum is the international convention center, where all of your fellow Guild Members meet... You have passed the final test for admission... not enough money, and not time. (secret decoder ring and handshake instructions coming soon...)

Seriously, those are very, very common issues with home studio building. There's a solution for one of them, but not for the other....

There will be more budget available in the future to make adjustments and improvements, but for now, I need to get something up and running for around £10-15k.

That's the one that DOES have a solution! 15k will get you started, and likely advanced enough that you can use the space to do some initial mixing, while you save up more budget and carry on working on the rest of the place. It's the best solution. So you build in stages, as funds become available. That's the solution. However, it still does require that you design the complete studio in advance, in full detail, before you start building anything. You can't design bits and pieces as you go: take that as first-hand truth from a studio designer. This does not work. When I'm designing a studio for one of my customers, I very often get to a point where I need to go back and change a whole bunch of things because of something that just came up that I hadn't seen before. And you can't do that if the studio is already built! Tearing down parts of your newly completed studio to make modifications that you didn't foresee, is a rather sad situation. Changing stuff on paper or in the computer model is relatively easy, and costs you nothing in materials or contractors... so it's far better to work through the entire design for the complete studio, both upstairs and downstairs, double checking every aspect. before you ever by a single 2x4 or raise your hammer for the first time.

And, just to add a bit of extra stress, I need to try my absolute hardest to get it done in the next 2 months or so.

This is the one that "has no solution". Sorry. It just doesn't. There is no way, at all, zero, zilch, none, that you would even be ready to start building in two months from now! Even if you were already an experienced studio designer, and already knew exactly what you wanted, it would take you longer than 2 months to just design the place. I'm sure you don't want to hear this, but it's the full, ugly truth. The very fastest I have ever managed to design a complete studio in detail, is about 6 weeks. And that was a simpler studio than yours: just one single room. There's a huge amount of effort that goes into a studio design. Yes, an experienced studio designer could possibly take an existing design and adapt it to fit your building inside a couple of weeks, but it would not be optimized, and it would not be YOUR studio, specifically designed for YOUR needs, on YOUR budget.

So I'd urge you to rethink this, and allow yourself about a year to have the place finished. That's realistic. That's from personal experience.

Let's look at this objectively: You have doubts about how to approach the basic build, in terms of isolation, construction materials, acoustics, and layout. You did not even mention HVAC; which is a large part of studio design. Yes you absolutely do need it: remember that I mentioned "hermetic seals"? Well, with your double air-tight full perimeter hermetic seals, guess what cannot get in and out? Yup: air. In a typical house, office, school, shop, church, etc. there are numerous tiny air leaks all over the place, and air has no problem getting in and out (hence the poor isolation). But in a studio, there are no such air leaks. Thus, no air. And since I'm sure that you are rather partial to breathing, and would really not like to stop doing that, then it's clear that you need HVAC. It's not a luxury in a studio: it's basic life-support. Yet, you didn't mention it much. But HVAC design for studios is a huge thing. I often spend more time designing the HVAC system for a studio, than I do on designing the studio itself.

So you need to know all about acoustic isolation, acoustic treatment, HVAC, structures, materials, techniques, design, etc. You recognize that you don't know a lot about those, so you'll need to learn. You already have Rod's book, which is great, but you will also need another book: "Master Handbook of Acoustics" by F. Alton Everest (that's sort of the Bible for acoustics). You'll need to study that until you understand all of the principles, then you'll need to study Rod's book again, carefully, to see how the theory you learned in MHoA is actually applied in real studio design. That alone will take you about two or three months, just to learn the stuff well enough that you can apply it. Then you need to learn the software that you'll use to design your place: SketchUp is what most people on the forum use, and I saw you already made a start with that. It's really powerful, but it takes a bit of learning. Call that another month or so until you really get the hang of it, practicing a few hours every day. Then at least two months to actually design your studio, probably more like three or four, as you work through the issues, try out different approaches, scrap things, start over, and gradually put the bits and pieces together in the way that makes the most sense.

... including the HVAC system! ... which means you'll need to learn all about latent heat loads and sensible heat loads and climate in your area, and static pressure, and silencer boxes, and insertion loss, and flow rates, and flow volumes, and noise levels, and many other things. Once you have mastered those, then you can design your HVAC system: it will need to move the correct amount of air (volume per unit time, or flow rate) at the correct speed (distance per unit time, or flow velocity) for your room, while removing the correct amount of heat and humidity (they go together) in the form of latent heat and sensible heat, while also bringing in the correct amount of oxygen (fresh air) from the outside world, and simultaneous dumping the correct amount of CO2 and other stale gasses that you don't want (exhaust air), and doing all of that for varying conditions of occupancy (number of people, amount of gear, instruments, etc.) and for various climate conditions. It has to be able to handle a full load of frantically jamming musicians on the hottest, most humid day in mid-summer, with mountains of gear and lights turned on, steaming pizza, hot coffee, etc, and it also has to be able to handle the the minimal load, of just you sitting quietly, alone in the dim dark in mid winter as you contemplate your next move. And it has to do all THAT while not letting any sound escape from your thumping, booming, screaming sessions... That's NOT an easy task! So you'll be doing quite a bit of research on HVAC...

So you have about four to eight months just learning and designing. Realistically. Objectively. That's what it takes. Then another four to eight of actually building, and likely more if it will just be the two of you doing all the work. Some of my customers do build their studios themselves or with a helper, and it seems to take them about a year, on average, from the moment they pick up the first stud and nail, until they sit down to actually do the first session in the finished studio, for studios such as yours.

Only then, once your design is completely finished in every detail, and double-checked, only then will you be able to go out and buy materials and tools, and start actually building the place.

Sorry to rain on your parade and enthusiasm, but rushing to build a studio is always doomed to failure. It does not work. If you look over the forum, you'll find a few threads where people tried that. Not a single one of them succeeded. Not even one.

In terms of what sort of level I mix at, I have no idea - I have ordered a meter and that information will follow on, but as a quick rule of thumb, I use Genelec 1031As and have always considered that their “overload” light is there to tell you when it sounds just about loud enough

Well, according to the manual, a pair of those can put out 120 dB peak for short periods without frying themselves, but more like 110 dB each in typical half-space applications, or 101 dB when limited by driver protection circuitry. So two of those driven to limiting would be putting out around 105 dB RMS, and maybe 120 dB peak. However, you'll need to get your meter out (set it to "C" and "Slow") to actually check real levels on YOUR system playing YOUR music.

But let's call it 110 dB inside the control room, to be safe. (That's actually illegal and unsafe for a workplace, but getting deaf is your own choice if this is a hobby studio, so I'll leave it at that.) Now, to determine how much isolation you need, you'll have to check your local municipal noise regulations. They will specify what the maximum level can be OUTSIDE your studio, and they will also specify where that level must be measured, and how to measure it. Let's assume it's a typical residential regulation, and specifies 40 dB at night (I'm assuming you want to use your place at night). The math is simple: you need to create isolation that will reduce 110 dB inside to 40 dB outside. So you need 70 dB of isolation. You might also have the benefit of distance: sound attenuates over long distances, so you might have a few dB advantage if your garage is quite a way form your property line. Or you might not.

So that's the figure you are aiming for: 70 dB of isolation. That's HUGE! That's a MAJOR task. Not impossible, but that's pretty much the limit that you can expect for any home studio build, even with a large budget. It is possible to go higher, but you'd need to add a couple of zeros to the budget.

Here's some perspective: A typical house wall provides around 30 dB of isolation. The decibel scale is logarithmic, not linear, meaning that it gets harder and harder to get one extra dB, the further you go up. So going from 30 dB to 31 dB is a piece of cake, but going from 100 dB to 101 dB of isolation is hundreds of thousand of dollars, and huge amounts of mass.

In fact, every time you go up by 10 dB, you need to block ten times more energy. So a wall designed to provide 40 dB of transmission loss (isolation) needs to block ten times more energy than the standard house wall that only does 30. And a wall that blocks 50 dB needs to block one hundred times more energy than the house wall (10x10). And the wall that has to provide 60 dB of isolation must block 10x10x10 = one thousand times more energy than the house wall. And your wall that needs to produce 70 dB of isolation, must block 10x10x10x10 = TEN THOUSAND times more acoustic energy than the standard house wall....

Perspective.

Your isolation system has to be impeccably well designed, and impeccably well built and you need a large budget to do that. Not impossible... just not very easy, and not very cheap.

So, your solution here is to either turn the volume down, or go with less isolation and hope the neighbors don't call the cops on you too often. As a point of reference, most engineers mix at around 85 dBC, since they consider that to be comfortable, good for producing mixes that translate well, and good for long sessions without causing ear fatigue. And that also turns out to be level that studios and cinemas are calibrated for... and is also the maximum permitted legal level for workplace exposure, for normal 8-hour shifts.

Just sayin'!

People always tell me its very loud!

Those people are right! Very right.

I am probably going to incorporate some sort of switchable sub into the room as well, to run with the Genelecs for a bit of extra BS factor during overdubs.

Ummmm.... OK.... so adding a sub to the situation makes it even more complex: low frequencies are the hardest to isolate, and travel long distances in open air very well... So you will need even more isolation....

I realize the dimensions I have are by no means ideal, but they are what they are, so I have to somehow deal with it –

But you CAN change the actual dimensions of your final inner-leaf room! It IS a choice you can make, to optimize the acoustics. Room modes... room ratios... Even just designing your side walls conventionally and your front and back walls inside-out would make a difference in the ratio, moving it off-square. Maybe not enough (I didn't do the math), but at least something. Or you could like into the theory of control room design, and come up with a set of dimensions that absolute optimizes and maximizes your acoustic response, to get it as close to neutral as physically possible...

especially the lack of ceiling height.

I already mentioned this, but I'll repeat it: do your ceiling inside-out. You get to maximize acoustic height (which is what really matters), improve low frequency diffusion, eliminate flutter echo in the vertical plane, and get several other advantages.

For simplicity and budget's sake, I am just considering the downstairs room for the moment.

As I mentioned above, you can start the CONSTRUCTION of the control room downstairs first, but the DESIGN needs to be complete for the entire studio before you can do that.

a) Wall Construction – from outside to in, what is the best possible combination for me to use?

That would be the one that provides the amount of isolation that you need (dB TL, or decibels of transmission loss), for the cost that you can afford, using the materials to which you have access, and the techniques and tools that are available to you. Since we don't know that "amount of isolation that you need" is, it's also hard to say what the best way to build your wall is.

Existing Concrete Block
Gap - what size?
50mm insulation
2 layers 16mm plasterboard -

Yes. So far so good, except that the entire air gap needs to be completely filled with insulation to maximize absorption of cavity resonances, thus improving your isolation greatly at low cost.

would a 3rd layer of 12mm or 18mm mdf sandwiched in the middle improve this much?

Depends on what you mean by "in the middle": if you mean "in the middle of the air gap", then no, it would not help, but if you mean "between the two layers of 16mm drywall", then yes, that would help. Not because it is MDF, but simply because it is mass. Sound waves can't read price tags, so they have no interest in how much you pay for your mass. You can use really expensive mass, or really cheap mass, but all they care about is the actual mass itself. The only advantage to you is the thickness of the mass: high density (expensive) materials take up less space. If you use low-density material (cheaper) you need to make it much thicker to get to the same amount of mass. So instead of 32mm of drywall (two layers of 16mm) you could use just 2mm of lead sheeting, for example, and still have the same mass, or you could use 500 mm thickness of solid cardboard, or 60 mm of balsa wood, or 4mm steel plate. But apart from the cost, there's the practicability of making your walls from lead sheet, cardboard, or steel plate....

So the point is not the material itself: it's the mass that matters. Or rather the surface density. The higher the surface density, the lower your MSM resonant frequency, and therefore the better your isolation in the low end of the spectrum, which automatically implies better isolation across the rest of the spectrum. So your objective is to find the material that gives you the most mass for the least cost.

However, you do need to do the math here: you need to calculate the amount of mass you'll need on your inner leaf, and the size of the air gap, by using the equations for MSM resonance, coincidence, mass law, etc.

Stud (suggested size was 75mm x 35mm, but if I use 100mm, is that a problem?)

75mm x 35mm is pretty close to standard 2x4 lumber (89x38), which is commonly used for studio design, and commply spaced 400mm OC or 600 mm OC in some cases. You can go up to a larger size if you need to, but why? It's more expensive, takes up more space, harder to work with, and doesn't provide any real benefit.

Insulation between studs 100mm
Treatment and finish.

You seem to be missing the point of John's inside-out wall design: the insulation in the stud bays IS the treatment. Or rather, it's the basis of the treatment. It might remain just like that, with nothing else (except for a fabric finish), or it might have wood slats over it, to form a slot wall (if sealed and tuned) or a partially reflective, partially absorptive surface (not not sealed and therefore not tuned), or it might have even more insulation over it (bass trap), or it might have something else. Each part of each wall will be designed to deal with the specific acoustic situation that affects that specific location in the room. John's inside-out walls are not just a general "one size fits all" solution. They are merely the basis if the entire acoustic treatment plan for the room, as a whole.

Does that work? Or am I throwing more materials at the problem than is necessary, for not much real gain?

The basic approach is fine, except that I'd swap your 100mm studs for standard 2x4's (whatever they happen to measure where you live), and then add treatment as needed for each part of each wall. And I'd also do all the math to make sure the isolation is sufficient for what I want, at the frequencies where I want it.

The other option is a staggered double stud with 3 sheets on the outside of each stud and insulation between.

Does this constitute a triple leaf wall with the concrete block?

Yes, most definitely. It also constitutes higher cost, more materials, slower progress, and less isolation.

Or does the concrete block not count as a leaf if it is standing on its own? I have searched, but I could not quite untangle that information.

Yes. The concrete block leaf counts as a leaf, due to the definition of a leaf: A leaf is just a massive, hard, solid surface that happens to be located close to (and roughly parallel to) another such massive, hard, sold surface, with a gap in between them that happens to be filled with air. What REALLY defines a leaf is that there's air next to it, followed by another leaf. It's the air that creates the resonant system between them. The air is the spring. It's the "S" in the MSM equations. It does not matter how the leaf (the "M") on either side of the spring is supported: that's irrelevant (mostly). The leaf could be self-standing, or supported on studs, or hung from sky-hooks, or held in place by magical incantations! The only thing that matters is that there's an air gap, then another leaf. That makes an MSM system. If there is yet another air gap beyond that, followed by yet another leaf, then it's an MSMSM system (3-leaf system), which means that you need different equations to figure it out, but the leaf is still a leaf simply because it has an air gap, then another leaf.

b) My builder is suggesting that instead of building a concrete block wall across the garage doors, we fix sheets of 18mm ply to both sides of a 4x2 stud frame and fill it with kiln dried sand.

You COULD do that, yes, but how would you ensure that the enormous weight of the sand will not pop the nails eventually, and allow the sand to leak out? And why would you do that, when concrete block construction is relatively simple and inexpensive? And what lab would you test that construction in, to make sure it does work the way you hope it will work? Or do you already have lab test reports that show how such a system performs when tested under controlled conditions in a reputable acoustic test laboratory, and you are certain that you can build yours the exact same way they did?

I am in the process of working out the mass figures, but there might be something in the theory that the additional mass might be a good starting point for the back of the room. Any thoughts on this?

Where did you figure the additional mass would come from? A concrete block wall 237 mm thick, rendered both sides, will have a surface density of around 350 kg/m2 (assuming the normal densities for such materials). But let's assume that your materials are not quite like that and only work out to 250 kg/m2, just to be safe. The density of your sand-filled wall would be about 143 + 8.2 + 8.2 = 160 kg/m2 aprox. . That seems to be about 36% LESS mass, not more mass. Or am I missing something?

I'm also not sure what you mean by "the theory that the additional mass might be a good starting point for the back of the room". Do you have a link to that theory? Where does it come from? I have not heard of it before. Do you mean "good starting point" for isolation? or "good starting point" for treatment? Those are two different things.

2 sheets of 16mm plasterboard and probably another layer of 15mm ply on the floor above.

Have you done the math? Did you have a structural engineer check that? You would be putting an additional dead load of 35 kg/m2 on those joists. That's over one thousand two hundred kilograms of extra weight, in addition to what is already there, and we have not even looked at your inner-leaf walls for that room, nor the live load (people, gear, instruments, furniture, etc) That seems like a hell of a load for 2x8 joists. My span tables are showing that you'd need at least 2x10s for that load at that span, and likely 2x12's... and that's not even considering the weight of the inner leaf.

It would be far, far better to support your new inner-leaf ceiling on your new inner-leaf walls, and to do it "inside-out", for the reasons I outlined above.

Especially considering that you will need to add considerable mass to that floor above you anyway, just to get the 70 dB isolation that you need for the control room.

Is this going to provide enough isolation?

No.

it feels a little like the weak point of the build

That's because it is!

but I am hamstrung by the ceiling height.

Only if you do it wrong. If you do it right, there are options open to you. It can be done, just not in the way you were imagining.

d) Floor.

It's already finished. Nothing more to do here.

do I actually need to build a stud floor on top?

No. Here's why: http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173 . That's the plain truth. Trying to add a floor over your slab would be silly, as it would make matters worse in every sense, cost you a lot of money, and produce no benefit, in addition to eating up precious room height.

Or can I use some sort of dpm, acoustic underlay and go straight to a layer of ply and a combination of laminate and carpet tiles or similar?

The floor is already finished. You can't beat a solid concrete floor for a studio. There's nothing better under the sun. Just what the doctor ordered. The tiles are fine too. If you wanted to gain a few extra mm of height, you could take those off (lots of work), or you could just leave them where they are. No problem, acoustically.

If they are in a bad state, or ugly, or you just don't like them, them lay laminate flooring over them (on ordinary underlay), and that's it. However, anything you do to your floor is going to cost money, and you are on a very tight budget, so I'd recommend doing nothing, and save that money for the rest of the build.

Oh yeah, I forgot the HVAC haha… It’s England, it’s always cold and raining right? I guess I need to look into this…

Ahh! I missed that on the first read! So you DID mention HVAC! The answer is "yes"... you will need to look into it... in fact, quite a bit more than just "look into it"!

Design will follow in a week or so.

I'm looking forward to seeing that, but I have a feeling you are being just a tad optimistic in estimating that you can have a complete studio design done in a week...


- Stuart -

[cmp]

Hi there "CMP", and welcome to the forum!

Wow! Thank you so much Stuart for taking the time to reply at such great length and in such detail. I've watched you do this for many others on the forum and am really very grateful for the time effort you have put in, to set me off on the right path. You have answered a lot of my basic questions and have opened my mind to the depth that I might need to go to, in order to do this right.

If it is of any comfort, I've been hired on a couple of occasions to fix big-money rooms such as the ones you describe, and I know John has too. I'm talking about rooms that were designed by big-name studio designers, and had large price tags attached, but where the owners were far from happy with the outcome. I won't be mentioning names, but it's surprising that designs where lots of dollars were spent could turn out so bad, when they clearly and obviously defy the laws of physics, or the brief of the owner.

It has always been a source of some confusion for me. I spent maybe 2 decades working predominantly in various studios in 2 of the biggest purpose-built, multi-studio complexes in the UK and between their combined 8 commercial control rooms, I considered 2 to be very good, perhaps 2 more to be useable and the other 4, I would avoid altogether. That's not much of a return on a £12m investment! Maybe that goes some way to explain my nervous suspicion haha.

And since you already admitted that you haven't paid a lot of attention to the empirical side of acoustics (figuring out why some rooms are good and others are bad, despite the budget), to get to your goal you'll probably need to take the other track: theory, math, science, research, study...

Yeah, I was afraid you might say that...

...237mm of concrete+render is a nice sized chunk of mass. If you really want to go for high isolation at low cost, then you could paint that wall with something that will even seal the pores in the render, before you move on to building your inner-leaf wall. The pores can play havoc with the isolation, as they do allow the air (and thus the "vibration of the air") to penetrate into the wall surface. Sealing prevents that. Masonry sealer would be good, or even a cheap wall primer.

Good advice - will get straight onto this.

Yep! For two reasons:

1) It is square. which is about the worst possible shape, acoustically, as all the modal resonances in the "length" direction will occur at the exact same frequencies as the modal resonances in the "width" direction, so you'll have some very large modal issues at just a few very specific frequencies, with very large gaps in the low-end spectrum in between them... Not a good situation, so you'll need to look into the theory of room ratios, modal spread, room, modes, ratio calculators, etc. You will have to make sure that your inner-leaf room fixes this problem, by NOT having the same dimensions, nor dimensions that come with about 5% of being the same, or being a direct multiple of each other. Use one of these Room Ratio calculators to figure out the best dimensions for your room:

http://www.bobgolds.com/Mode/RoomModes.htm

http://amroc.andymel.eu/

Both of those are very good, and will help you to decide how best to build your room. They give you tons of information that is really useful to help figure out the best dimensions.

2) Low ceiling....you have precious little space in the vertical direction, so you will have to take very special, extra-great care to lose as little of that as possible when you put up your inner-leaf ceiling. I would suggest giving vary careful consideration to using John's famous "inside out" concept for your inner-leaf ceiling. It has man advantages, one of which is allowing you to keep as much acoustic height as is physically possible. Another is that it automatically provides lots of diffusion at low frequencies, and also provides space where you can have plenty of treatment, that helps to "raise" the ceiling, acoustically, so that it seems higher than it is, psycho-acoustically.

All noted.

There's a document from the ITU called BS.1116-3 that lays out the specifications for "critical listening rooms". So your next priority is to lose as little floor area as possible, ideally keeping it well above 20m2, but also taking into account that you WILL lose at lot of area due to the need to isolate, and you WILL need to reduce the room width to fix the modal issues.... so this is where you need to learn how to juggle! You have to keep a lot of balls in the air as you fiddle and twiddle and tweak, to maximize both space and modal response and isolation and building materials and budget and internal acoustics...

I do like a nice bit of light bedtime reading

The underlay and carpet can go: no use to anyone. The 18mm chipboard is a pretty lousy base for your upper rooms, and you will DEFINITELY need to beef that up with substantial extra mass. However, you are going to need to hire a structural engineer for this part, since you need to know how much extra mass you can add to those skinny 2x8 joists that are going to be supporting your upper-rooms. Those joists are not very big, and they are spanning at nearly 6m, so there's not a lot of live load or dead load available here. Those things need to support not just the floor, people, gear, and equipment, but also your entire inner-leaf rooms! That's a lot of mass to shove on top of a few 2x8s. I have a feeling you'll need to beef those up as well: maybe sistering each one with a second 2x8 right next to it, screwed and glued, or bolted, would likely do the trick. But you'll need a structural engineer to tell you if that is acceptable under your local building code, and how to do it, and what the final load-carrying capacity will be.

This is in hand, structural engineer booked. Assuming we get the joists in shape to support everything, what sort of materials/mass would you suggest on the floor of the upstairs?

The walls and ceiling are all 12mm plasterboard, insulated, but with what, I have no clue.

You'll find out when you take off the drywall, which you WILL need to do, in order to create the isolation system that will give you the isolation you need for the use you are planning...[/quote]

Bit concerned about this going forwards. Not too sure how I will ever get the isolation on the roof planes. There is not enough room or height to build a full inner room. I am planning a good sized, sealing, double guitar amp box at one end of the space, which I am fairly confident will be efficient enough to cope with the level i need, before it even gets into the room, let alone outside. I am not planning on having drums up there. Vocals are the issue. Vocals late at night. Loud vocals late at night. The singer screaming his head off, when all around is quiet in the dead of night. What can I do to stop the neighbours going medieval? Assuming I have stripped the drywall off, and I am looking at the underside of the roof tiles, the tile battens and a bit of bog-standard roof insulation, what is going to give me some reasonable isolation here?

Unfortunately, that isn't really an option. The reason, once again, is simple: You cannot allow multiple large holes in your isolation system. Each hole is a major weak point. The general rule in studios is that you can allow just one very small penetration through the wall, to bring in your electrical power feed, and then distribute it internally, inside the room, using surface-mount electrical systems.

Yep I see that now. Its all coming out!

Welcome! You finally made it! You are now a confirmed member of the Insane Studio Builders Guild! And this forum is the international convention center, where all of your fellow Guild Members meet... You have passed the final test for admission... not enough money, and not time. (secret decoder ring and handshake instructions coming soon...)

Thanks!

15k will get you started, and likely advanced enough that you can use the space to do some initial mixing, while you save up more budget and carry on working on the rest of the place. It's the best solution. So you build in stages, as funds become available. That's the solution. However, it still does require that you design the complete studio in advance, in full detail, before you start building anything.

I get this. I was going to disagree for a minute, but you are right.

This is the one that "has no solution". Sorry. It just doesn't. There is no way, at all, zero, zilch, none, that you would even be ready to start building in two months from now! Even if you were already an experienced studio designer, and already knew exactly what you wanted, it would take you longer than 2 months to just design the place. I'm sure you don't want to hear this, but it's the full, ugly truth. So I'd urge you to rethink this, and allow yourself about a year to have the place finished. That's realistic. That's from personal experience.

Can I just skip over this bit

Unfortunately, a year is a complete non-starter for me. I am producing and mixing for a living and like everyone else, I have bills to pay and people to feed! So perhaps what I have to accept, is that if I was going to gather the knowledge to do this all myself properly, then yes, for sure it would take that long. However, my real world situation wont go anywhere near allowing that, so I am going to have to find some other ways of doing this. I have a couple of experienced people that I can get help from in terms of the design. I also have a studio HVAC guy that, although I hadn't budgeted for him, will shave off a lot of time and effort. Sketch-up, I am leaving alone. I've got a pencil and some paper haha. There is a month of my life back right there! Seriously though, I fully understand why you say what you say, but I need to get something workable together quickly. I had said 2 months, fully expecting 4 (hope my builder isnt reading this!), so that is the time that I have to do the best possible job that I can. After that, although its obviously nowhere near ideal, I will have to amend the finer details later, over the following 12 months. That's just the way it is.

Sorry to rain on your parade and enthusiasm, but rushing to build a studio is always doomed to failure. It does not work. If you look over the forum, you'll find a few threads where people tried that. Not a single one of them succeeded. Not even one.

No need to apologise - warning noted. I come at it from a slightly different angle perhaps, but I do accept your experience of doing this as often as you have.

...let's call it 110 dB inside the control room, to be safe.

On measuring today, its more like 100db, but I get your point that it is still going to need a lot of isolation.
I think maybe we can forget the sub too...

However, you do need to do the math here: you need to calculate the amount of mass you'll need on your inner leaf, and the size of the air gap, by using the equations for MSM resonance, coincidence, mass law, etc.

OK.

You seem to be missing the point of John's inside-out wall design: the insulation in the stud bays IS the treatment. Or rather, it's the basis of the treatment. It might remain just like that, with nothing else (except for a fabric finish), or it might have wood slats over it, to form a slot wall (if sealed and tuned) or a partially reflective, partially absorptive surface (not not sealed and therefore not tuned), or it might have even more insulation over it (bass trap), or it might have something else. Each part of each wall will be designed to deal with the specific acoustic situation that affects that specific location in the room. John's inside-out walls are not just a general "one size fits all" solution. They are merely the basis if the entire acoustic treatment plan for the room, as a whole.

Yep, I was missing the point. This makes much more sense.

Where did you figure the additional mass would come from? A concrete block wall 237 mm thick, rendered both sides, will have a surface density of around 350 kg/m2 (assuming the normal densities for such materials). But let's assume that your materials are not quite like that and only work out to 250 kg/m2, just to be safe. The density of your sand-filled wall would be about 143 + 8.2 + 8.2 = 160 kg/m2 aprox. . That seems to be about 36% LESS mass, not more mass. Or am I missing something?

No, I dont think you are missing anything. I had wrongly assumed it would have more mass - he had previously been asked to use this method on an build by a designer. Looks like a non-starter.

It would be far, far better to support your new inner-leaf ceiling on your new inner-leaf walls, and to do it "inside-out", for the reasons I outlined above.

Message received.

Design will follow in a week or so.

I'm looking forward to seeing that, but I have a feeling you are being just a tad optimistic in estimating that you can have a complete studio design done in a week...
- Stuart -[/quote]

Ok, make that 2 weeks

Thanks again for your patience and the effort that you put in.

I have much to do over the next few weeks. Feels a bit like a massive huge mountain right now, but if I go back and stand in the space, I feel a little more comfortable with the scale of what needs doing.
It's just a few stud walls and some plasterboard and insulation right?
F.Alton Everest is on the way....

cmp

[Soundman2020]

This is in hand, structural engineer booked. Assuming we get the joists in shape to support everything, what sort of materials/mass would you suggest on the floor of the upstairs?

Basically, as much mass as possible! Here's the part you ain't gonna like: You need your "outer-leaf" to be consistent on all sides, and the "ceiling" of your control is a "side". Since your outer-leaf walls are massively heavy, the ideal situation would be to have a massively-heavy outer-leaf ceiling as well, with the same mass as 237mm of concrete block and render.... Obviously, with 2x8 joists, there is no way under the sun that this can happen. You'd need some rather more substantial joists up there, probably RSJ's, implying lots of cost... big money.

However (and you won't like this part either...) there's the major issue that you want to do this on two floors, one above the other, so you will ideally need a "stacked pair" of isolation systems: One for the control room downstairs, and the other for the live room(s) upstairs. And since the ceiling/floor in between them sort of has to be firmly attached to the outer-leaf walls, it cannot be part of the inner-leaf for either upstairs or downstairs! It has to be separate. And that creates a conundrum, because it has to be there to support the upper floors...

So here's one way of doing it:

CMP-two-storey-studio--principle.jpg

That's just a very quick, simple mock-up that I did to show the principles, but NOT the details!

You'd build your control room downstairs as normal, sitting on the slab, and since that is a slab-on-grade, you do not need to "float" the control room floor: the concrete slab is perfectly fine all by itself. So you'd build your control room as a set of four walls that sit on the slab, not touching the outer leaf, with a ceiling sitting on top of those new walls, also not touching anything. Then you would re-build your current floor in such a way as to make it very strong, perhaps as another concrete slab, trying to get close to the same surface density as the existing walls. That would the be the outer-leaf for the control room, so you'd be fine there: you'd have a fully-decoupled two-leaf MSM isolation system for your control room, and considering the mass you have there, it would isolate VERY well.

Then you would build your live room (I'm assuming just one single room upstairs) as a fully floating room on top of the new ceiling/floor that divides the space. That would need to be properly floated on isolation mounts, suitable tuned to isolate the room down to the lowest frequencies that you need to isolate, and with enough mass on all sides (floor, walls, ceiling) to provide the level of isolation you need. I did not bother showing the isolation mounts in the above rough diagram, but I'd suggest something from Mason Industries.

Yes, that is a three-leaf system that divides the two rooms, but you have little choice here. It would need to be designed with the 3-leaf problem in mind, to compensate for the lost isolation, but it's still the easiest system.

Yup, I can see your jaw sitting on the floor right now, and the dollar sign (or Euro signs...) flashing up and down your eyeballs, cartoon style, while tiny little birds orbit your head.... This is why I said what I did yesterday. When talking about your upper floor, you said "... and I’m guessing that’s where the problems continue!" to which I replied "Yup! For sure! Big-time...". This is what I was talking about. Trying to have a studio on an upper floor is a "big time" problem always. Because it needs to be both supported structurally, and also isolated acoustically, which very much implies that it has to be "floated" in some way.

Yes, I did link you to a long post yesterday that explains in great detail why you do NOT need to float your floor in your control room, but that very same post did mention that if you have a studio on an upper floor, and you need high levels of isolation, then you probably will need to float it. This is about the ONLY situation where I'd recommend floating a floor, or an entire room: most of the time it simply is not necessary, and that's why I get so annoyed by all those videos on YouTube with gullible people attempting to float their low-budget studios on rubber pucks and 2x4s and a plywood deck, and thinking they are doing something wonderful.... when in fact all they are REALLY doing, is making things far worse!

So, your control room does NOT need floating because it will be resting on a concrete slab on grade. Your live room DOES need floating, because it will be on an upper floor, and the floor it will be resting on is attached only to the outer-leaf walls, which make great loud-speakers when you make them vibrate by directly transmitting loud sounds into them, and will broadcast your drums, bass, growling electric guitars, percussion, and everything else, nicely loud and clear, to the entire neighborhood, for several blocks around in all direction!

That's the sad truth. And NOT what you wanted to hear!

All of this is necessary because you have a need for rather high levels of isolation, since you admit to a love for tracking and mixing as loud as possible, at well over 100 dBC, and likely close to 120 dBC. In order to get that down to legally acceptable levels (or at least levels where the neighbors are not knocking on you door with flaming torches and pitchforks....), requires a LOT of isolation. And getting a lot of isolation for low frequencies requeires extreme measures, that cost a lot of money.

I wish I had better news for you, and could tell you about this ultra-secret new "Sound Destroyer" material that you can paint on your walls and it will totally kill all sounds, for just two dollars per square meter, but I can't. It doesn't exist. The pixies went on strike, and refused to provide any more dust for making it, the unicorn ran away after it realized that it's entire horn would be used in producing the material, the elves stopped working on the production line when the unicorn ran away, and the fairies folded their delivery network when the pixies quit! So sorry, there's no more magical materials left. And we are stuck with the laws of physics!

So, to summarize: You need very high isolation because you track and mix loud. That implies high mass, which you actually do have in your existing walls and slab, so that's in your favor. But you do not have it in your ceiling or roof, so that's against you. You can get it by "beefing up" your existing ceiling with a large amount of mass, which can be done at relatively low cost, as long as you do not need to load anything else on top of it. But you DO need to load other stuff on top of it, because that's where your live room will go! So you need to beef up your ceiling even more, and the cheapest, most effective way to do that is to replace it with a concrete slab. That would allow you to float your upper live room completely, which you do need to do, because you'll be tracking loud stuff up there.

Which leaves the roof: In my quick and dirty diagram above, I show the final roof as a flat concrete slab. But that's not your situation. You have a gabled roof, tiled, and nothing else. So that will also need to be beefed up, to provide the level of isolation that you need for your live room.

I really , really hate to rain on your parade like this, but you DID ask why some places work and some don't, and this is one of the reasons: not paying attention to the laws of physics and the science of acoustics. The sad but unavoidable truth is that you cannot get high isolation without a lot of mass (unless the pixies and unicorns return to work...). Mass is expensive, and it is heavy, so it needs structural support, which is also expensive. That's just the way things are, unfortunately.

Bit concerned about this going forwards. Not too sure how I will ever get the isolation on the roof planes.

Right! There are ways to do that, using thin, dense materials such as fiber-cement board, or even lead sheeting (probably not allowed). It is possible.

There is not enough room or height to build a full inner room.

True, but there is enough room to build a room that follows the same contours as the roof, and still get good isolation.

I am planning a good sized, sealing, double guitar amp box at one end of the space, which I am fairly confident will be efficient enough to cope with the level i need, before it even gets into the room, let alone outside.

Ahhh, but that's where the laws of physics that you don't like, can turn around and bite you! It is very possible to build a guitar amp isolation box that does a wonderful job of isolating your cabs when you test it out in your back yard, but then when you put it on the floor in the corner of your live room, it suddenly doesn't isolate at all well any more! People do come across that perplexing situation, and they blame it on Murphy's law, or something coming loose, or witches and black cats, or whatever, when they should really blame it on ignorance of acoustics, since it is entirely predictable. They forgot to take into account "resonance". The iso box by itself was not a resonant system, out in the back yard, but placing it on the floor and in proximity to walls can potentiality turn it into a resonant system. And resonant systems have one outstanding property; the do not isolate at their resonant frequency! In fact, not only do the fail to isolate, they can also actually AMPLIFY sounds at their resonant frequency...

So your iso box needs to be designed with the final location taken into account, to avoid such fatal resonances. And it also needs something that you haven't yet thought of: ventilation. Amplifiers are pretty good at putting out a lot of heat, especially when run at very high levels. And since all of their energy output will be trapped inside your box, it will get awfully hot in there, very fast... and suddenly your amp will go silent, probably accompanied by a puff of smoke, and an expensive burning smell.... Maybe even some pretty pyrotechnics! But you won't see how pretty they are, as they'll be inside the smoke-filed box...

To prevent that, you need to provide enough airflow to keep the amp cool. And THAT implies cutting very large holes in the box, so air can get through! But cutting holes in the box means that it does not isolate any more!!! !

The solution is to build in a silencer system as part of the box, that allows the air to flow, but prevents the sound from getting out. It can be done. Just one more of the many, many things that need to be taken into account when designing a studio...

I am not planning on having drums up there. Vocals are the issue. Vocals late at night. Loud vocals late at night. The singer screaming his head off, when all around is quiet in the dead of night.

so figure about 95 dBC, max, and only in the voice range. That's a little better than for drums, bass, or electric guitar! You can relax the standards a little here.

What can I do to stop the neighbours going medieval?

You could buy all the houses for a 3 block radius around you, and kick them out if they complain about the noise....

Can I just skip over this bit

You can yes.. but only to a certain extent, and only by throwing some more money at it...

I fully understand why you say what you say, but I need to get something workable together quickly. I had said 2 months, fully expecting 4 (hope my builder isnt reading this!), so that is the time that I have to do the best possible job that I can. After that, although its obviously nowhere near ideal, I will have to amend the finer details later, over the following 12 months. That's just the way it is.

I hear what you are saying, and you aren't the first forum member to say the same thing! You are in good company. Many people have the same problem. And they all get roughly the same answer: either you can do it right and get a successful studio that works, or you can rush it and end up with a really expensive mess that doesn't work. Sorry to be harsh, but that's what we are here for! To put the truth in front of you, even when it hurts, so you know what your options are, and you can then decide what path you want to take.

OK, so you don't have time to design it yourself, as it would take too long to learn acoustics, then learn building design, then learn structural design, then learn HVAC design, then learn Sketchup... Agreed. It does take a long time. Solution: Hire a studio designer to do it for you. He/she doesn't have to spend months learning all that stuff, like you would. He/she can just sit own and start designing, right away. With a bit of look, and a good designer, you can probably have the complete inside three months. Maybe inside two months, with a lot of luck (and a really good designer!).

Then the construction: you don't have time to build it yourself either: realistically, with you and another guy working on it in mostly spare time, nights and weekends, it will take about a year or so to do. If one of them is working full-time and the other part time, then maybe 6 months. That's realistic. Plus, buying all the tools you will need costs money. This is not a feasible path. Solution: hire a contractor to build it. He will come in with a team of people, each specialized in a certain area (framing, dry-walling, electrical, HVAC, doors, windows, painting, fabric, etc.) and in a couple of months or full-time, non-stop work it can be done.

If you did that, then it is possible to have your place done in four or five months, give or take. That's a very realistic, down-to-earth, estimate, based on real-world, first-hand experience.

This path costs more money, yes, but it gets the job done much faster, inside the time frame you have set for yourself.

So there's a trade off here: time for money. If you spend more money, you can do it faster. If you don't have more money, you can't. It's that simple, unfortunately.

Please don't misunderstand me: I'm not suggesting you should hire me to design your place. I'd love to, but I'm fully booked right now, for at least another month. I'd suggest that you contact John, and ask him for a quote. If John is unable, then PM me and I can put you in touch with other designers I trust, that won't scam you or produce a lousy studio.

I have a couple of experienced people that I can get help from in terms of the design.

I'd strongly suggest that you don't take that path. Designing a studio takes a lot of time, and effort, and concentration, and knowledge. Asking a friend or contact to help you out a bit is very unfair. It's asking for weeks of his time.... Either pay for the full service, or do it yourself. And if you are going to pay someone, then pay someone who already does it for a living, and has the track record to back it up. Don't try to cut corners to save a few dollars. In fact, the fee that a designer charges you might be less than what you are expecting, and he will SAVE you that amount of money, many times over, compared to you trying to do it yourself and making all kinds f rookie mistakes...

I also have a studio HVAC guy that, although I hadn't budgeted for him, will shave off a lot of time and effort.

Right, but unless he's also a studio designer, he won't be able to design it for you! He can certainly install it for you, but HVAC design for studios is a very complex thing.

so that is the time that I have to do the best possible job that I can.

Reality check!

1. You need very high isolation because you want to track and mix very loud. That level of isolation is expensive. You could save a lot of money just by turning your volume down! Think about that for a bit... Getting 50 dB of isolation is a hell of a lot cheaper than getting 70 dB of isolation. Turning down your monitoring level from 105 dB to 85 dB will save you a bundle. If you chose to keep the high levels, then you automatically choose to spend a lot of money. There's no other option here! Either you spend what you have and live with the results that you didn't want, or you spend what you NEED to spend to get the results you want. Or you lower your sights, turn it down, and spend the money you have to get realistic results. Reality. I'd love to drive a Ferrari, but I can't afford one, so I drive a Kia. Reality. You'd love to mix art 105 dB, but you can't afford to.

2. You need it designed fast, but you don't have the time to learn how and do it yourself. Therefore you need to pay a designer to do it for you. Reality. You can't have it both ways. If you try to cut corners by not getting it professionally designed, it won't do what you want it to do, and you will have wasted a stack of money.

3. You need it built fast, but you don't have the time, tools, knowledge, or manpower to do that. Therefore you need to pay a contractor to do it for you. Reality. You can't have it both ways. If you try to cut corners by not getting it professionally built, it won't do what you want it to do, and you will have wasted a stack of money.

Once again, sorry to be blunt, but sometimes it helps to have things laid out for you in plain sight, so you can get the big picture, even if it hurts.

After that, although its obviously nowhere near ideal, I will have to amend the finer details later, over the following 12 months.

This is possible, but not recommendable.

OK, final point in the reality check, related to this last point. And this is my best suggestion: the type of advice I'd give a paying customer...

Lower your sights. You can't afford what you say you want to do. If you lower your sights to a more realistic target, you can hit it. But you can't hit the target you are aiming at right now, with the budget you have.

What I would do: Forget the live room upstairs. Concentrate only on the control room, and make it usable to track vocals in. Put all your resources into that one singe room, which can be isolated a lot more easily (and more economically) than trying to do both rooms. First get the place designed, professionally, as a single-room studio with variable acoustics, then use your current funds to do the HVAC and electrical systems along with the isolation shell, and use whatever is left over for the minimal treatment in the room. Then as funds become available over the next year or so, add in the remaining treatment devices and room tuning, until it really does work well as a single-room studio.

That's reality. That's what I would do if I were in your situation.

On measuring today, its more like 100db, but I get your point that it is still going to need a lot of isolation.

You measured on "C" and "Slow", right? Just checking... "A" won't tell you the truth about loud music....

OK, let's say 100 dBC inside, and likely 40 dB outside, legal limit. So 60 dB of isolation.... still a tall order. I designed a studio for a customer in Australia that needed that much, since he teaches drums... five months design, over a year construction (him plus a carpenter), and we achieved that. It can be done, but not the way you are approaching it. PM me, and I'll send you some details about that build, if you want. It's rather similar to what you need.

No, I dont think you are missing anything. I had wrongly assumed it would have more mass - he had previously been asked to use this method on an build by a designer. Looks like a non-starter.

Some people build high-mass self-damped doors like that (sand-filled), but I'm not a big fan. Not because they don't work (they do), but because of the issue that heavy wooden structures tend to sag slightly over time, and a sagging sand-filled door tends to spill its guts all over the floor, one unexpected day.... I might consider it for a door, but not for a wall. There's just too much pressure at the bottom, and not enough strength in the wood and/or fasteners.

I have much to do over the next few weeks. Feels a bit like a massive huge mountain right now,

Yup. And once you get started on it, the mountain will seem a whole lot bigger... then you'll starting noticing that there's a whole bunch of other mountains behind it, and you've only really been climbing the foothills...

It's just a few stud walls and some plasterboard and insulation right?

Umm.... yeahhhh.. I guess so! Sort of like Neil Armstrong taking just that one small step... not much use unless the giant leap was already there, behind him!

F.Alton Everest is on the way....

Great! But it's a little ironic that you mention the word "Everest" in the same sentence as where you say you feel comfortable climbing the mountain in front of you...

OK, I hope I haven't totally trashed your dream of having a great studio that isolates well and doesn't cost much. In fact, of those three items, you get to choose any two! Just not all three. 1) Great studio. 2) High isolation. 3) Doesn't cost much....

Seriously, if you lower your sights a bit, and slow down a bit, you really can have a great studio. It wont isolate as well as you want, probably, meaning you'll have to turn things down a bit. And it will still cost more than you wanted. But the real way to get there is to hire a designer, first of all, and then see if you have the skills and time to build it yourself. If so, then great! If not, the bite the bullet and hire a contractor who has experience in studios.

PM me if you want details of that Australia build. I can't share all of that in public, as the customer has not agreed to that, but he doesn't mind me sharing in private.


- Stuart -

[cmp]

Another tome of very helpful information, thank you very much.
I have slowed down and taken your advice to concentrate on the control room, and we are working on a design. More on that later...

As a brief aside, I have started sourcing/researching materials and I have a couple of very basic questions:

Other than the tag of "acoustic" drywall, is there any critical difference between standard drywall and the "soundproofing" brands? I have found a 2400mmx1200mmx15mm board that weighs 29.5kg at nearly half of the price of the "Soundshield Plus" version, which weighs 30kg. It is made by the same manufacturer. The boards are exactly the same dimensions and weigh within 500g of each other. The only difference appears to be the blue paper on the "acoustic" version and the tapered edge, versus the grey paper on the standard version and the square edge. Am I right to assume that I dont need the "Soundshield Plus" version as its "all about the mass" right? We are all on a tight budget and whatever I save across upwards of 120 sheets, I can spend later when I inevitably run horribly over budget...

Cant remember the second question...

[Soundman2020]

Other than the tag of "acoustic" drywall, is there any critical difference between standard drywall and the "soundproofing" brands?

Not really, no!

Here's the thing: sound waves can't read price tags, and really don't care how much you pay for your building materials. They will not be impressed if you use high priced materials. The only things that really impresses them, are mass, springs, and damping! Mass (weight, density) is what stops sound, not price tags. There's no place in the equations for calculating isolation, where you can plug in a dollar sign, or Euro symbol.... All you can plug in is mass, air gap, and damping. That's it. (The "air gap" inside the wall, between the two leaves, is actually a "spring", acoustically, and the insulation that you put in the air gap is the "damping")

I have found a 2400mmx1200mmx15mm board that weighs 29.5kg at nearly half of the price of the "Soundshield Plus" version, which weighs 30kg.

The more expensive version might have a little extra damping, which could be useful. Do you have a link to the specs for that exact product? But if it is just mass, then that extra 1/2 kg is certainly not worth it, and the additional damping would have to be magnificently spectacular to justify the price. On the other hand, you cold add your own damping very effective, with a product called "Green Glue". It is NOT actually glue (despite the name), but it IS a very useful CLD (Constrained Layer Damping) compound. You spread it between two layers of drywall to damp certain types of resonance that would otherwise get through.

If the expensive drywall does have something like this inside it, then it might be worthwhile, but do check the costs carefully! Two layers of standard drywall with Green Glue in between might still be cheaper than two layers of the expensive stuff by itself.

The only difference appears to be the blue paper on the "acoustic" version and the tapered edge, versus the grey paper on the standard version and the square edge.

If that really is the only difference (apart from the weight), then get the less expensive stuff, for sure.

Am I right to assume that I dont need the "Soundshield Plus" version as its "all about the mass" right? We are all on a tight budget and whatever I save across upwards of 120 sheets,

You are very likely correct, unless there's an amazing damping compound inside the expensive stuff, layered between two thinner sheets of ordinary drywall.

There are no magical products in acoustics: all building materials obey the same laws of physics. So if you see some exotic expensive product that makes magical claims about being supere-dooper effective, always take that with a grain of salt, unless there's some real solid acoustic information to back it up.


- Stuart -

[cmp]

Still working on wall construction, among many other things. At the moment, I am looking at (from outside to in):

1st Leaf
Render (existing)
Concrete Block (existing) - painted

300-500mm Gap loose filled with a low density loft insulation

2nd Leaf
Stud 4x2
15mm drywall (mass 10.4kg/m2)
18mm MDF (mass 13kg/m2)
Green Glue
15mm drywall (mass 10.4kg/m2)

I am struggling a bit with the maths of that, but I am hoping that the gap is big enough for the STC to tend more towards a sum of the 2 leaves (couldnt find too much specific info on this other than page 330 of MHoA). Given roughly this quantity of materials (which fits the budget), do you think I have them in the right order? Obviously, I am trying to get as much isolation as possible, but this seems like the best I can achieve without building another concrete room (and that is not in the budget). Any tweaks or suggestions to improve things are very welcome!
I had envisaged building the walls inside out, but the practicality of overlapping the various layers, and the weight of a 5m run of wall would make it completely impossible to lift, so I have decided against that. Obviously, we cant build it from "behind' the wall, as there is concrete block in the way...

As anticipated, I am going backwards and forwards with the design. Its a 5.9m square and I had considered making it a rectanglular control room and having an air-lock for the doors and a booth down one side, but once the booth is of a reasonable width, it makes the control room too narrow for me, so I am sticking with a bigger control room. I am thinking that the recording space can wait until I get the upstairs sorted next year. As regards the control room ratio, I had got close to IEC 602568-13 1998 but only by wasting a lot of space at the sides, I'm not sure that is the right way to go, either. It's a great space but an awkward shape and size to use efficiently! The idea of an air-lock in one corner for the door doesnt really help with the symmetry either!

In the meantime, we are going to press on with removing the existing electrics, the windows and building a wall across the garage doors, as that is all set in stone regardless.