John Sayers' Recording Studio Design Forum Archive

Hi,

I've been a long time lurker of this forum and have just signed up as I'm in desperate need of some help/advice. I planned to build out my single garage into a small studio late last year but unfortunately didn't have time as I got ploughed under with work. Today my builder has visited me to say he has had a job cancelled and he will be here in the morning to make a start on my new studio. The only problem is I wasn't expecting the work to start for another month or so and I still haven't finalised any of my ideas or plans!!!!

I'll start off with my background, recording has been my living for the past 10 years and I'm mainly an engineer, but over the past couple of years I have been getting hired a lot more for production and mix work. I've just renovated a house that has a small garage (18.24 Sq Ft) in the garden and I'm looking to convert it into a mix room so I can work from home for mixing and overdubs.

What I need from the space
My garage mix room doesn't need to be huge, but it needs to be sound good and comfortably fit 4/5 people in for attended mix sessions.

I know a lot of the guys will advise against this due to the size of the space but I'll also need a ISO booth in the there. The reason being I work with a lot of pop and heavy rock bands and there are going to be instances where I'll need to record vocals and amps (all my drum tracking will be done at some of the studios I currently engineer at)

I've got a limited budget of £2000 for materials and I hope to include fixtures, fittings, doors and home made acoustic treatment in with that price but I will stretch to a little bit more if I need to.

The current structure and limitations of the space
The garage is 5.7 x 3.2 and the height to the roof joists is 2.2m, it is constructed from concrete blocks and has a slate roof, a concrete floor with a depth of 1ft, 1 double glazed window, a wooden exterior door and a garage door.

Link to garage plan / dimensions http://imageshack.com/a/img540/1881/usoDsa.jpg

There are a few limitations with my garage as it's parallel to my next door neighbours garden who have small children who play in the garden in the summer and can make a fair bit of noise, my neighbours also like to shout (a lot) so I really need to reduce this noise to a minimum inside the garage and make the ISO booth as near to silent from outside noise as possible. The next potential problem is my garage is only 24m away from a main road, so I need to reduce the road noise. The final issue is I need the sound proofing to be really really effective so anything happening inside the studio can not be heard outside as the garage is only 3m away from my neighbours extension and they always leave their windows open.

Image showing location of garage in relation to my neighbours house http://imageshack.com/a/img903/9899/tiFCkw.jpg

My initial design and soundproofing ideas....
I had two ideas for sounding proofing which both involve building a room within a room.

My first idea was the most costly building the studio walls from dense concrete blocks and leaving a small air gap between the outside of the wall and the exterior wall. My second idea involved exactly the same construction method for the ISO booth, but the walls in the mix room would have be constructed solely of plaster board to cut down on the cost.

Link to my initial ideas for soundproofing the walls http://imageshack.com/a/img540/4181/81mpNH.jpg

The last part of the puzzle was how to soundproof the studio ceiling and garage roof. Initially I wanted to add mass with sand bags, but the roof joists would not have support that amount of weight. The plan was to instead use 3 layers of plaster board attached to a frame, all bonded with green glue and skimmed with plaster, I would then use a double layer of dense/thick ply or chip board to add mass to the garage ceiling and cover with insulation.

Link to my initial ceiling design http://imageshack.com/a/img537/5895/xo8H3W.jpg


So that's as far as I had got and I hadn't finalised the dimensions on the control room and ISO booth but after lots and lots of research (and reading this forum) I don't think my designs and sound proffing ideas were ideal!!! I think I'm now going to scrap the concrete block idea and go with a room within a room built from 2 leaf stud walls as that would make for a quicker build and also keep the cost down.

My main worry with the space is the size and I need to try and loose as little space as possible to soundproofing and also the height as it's only 2.2m up to the roof joists. I've discovered today the garage sits on a concrete base that is 1ft in depth so I think this will give me enough mass to get away without having to put a floating floor in? which means I would loose less height with the build.

My last concern is my layout and I'm considering swapping around the ISO booth and control room so the booth is at the end of the garage where the entrance door is (although this is the end that backs onto the main road). I'm sure there is a better way to split the space up rather than into 2 rectangles rooms as I think there should be some kind of sound lock at the entrance separating the main door, control room and iso booth?

Any advice would be appreciated as I'm now frantically reading up all the information I can find on the internet. If anyone could point me towards any plans for 2 room studios of a similar size that I could use for inspiration and ideas that would also be really helpful.



Thanks
Ow

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

Today my builder has visited me to say he has had a job cancelled and he will be here in the morning to make a start on my new studio. The only problem is I wasn't expecting the work to start for another month or so and I still haven't finalised any of my ideas or plans!!!!

Well, this just is not in the least realistic, feasible, or even possible. Sorry. Not even close. Not even VAGUELY close. I don't mean to be insulating, but this reads something like a joke in poor taste.

The very fastest I have ever managed to complete a design for a garage conversion of a studio, is two months. That's at the edge of realistic. Overnight? Nope. Not even in Hollywood.

I've just renovated a house that has a small garage (18.24 Sq Ft)

Eighteen square feet? That's about the size of my guest toilet. Three feet wide by six feet long. Eighteen square feet. Something is waaaaay wrong here.

My garage mix room doesn't need to be huge, but it needs to be sound good and comfortably fit 4/5 people in for attended mix sessions.

You want to get 5 people in 18 square feet?

I know a lot of the guys will advise against this due to the size of the space but I'll also need a ISO booth in the there.

so now it's five people AND an iso booth, in eighteen square feet? The iso booth will have to be the size of a small garbage can.

I've got a limited budget of £2000 for materials and I hope to include fixtures, fittings, doors and home made acoustic treatment in with that price but I will stretch to a little bit more if I need to.

There seems to be a zero or two missing on the end of your budget. And the "2" should probably be an "8". I'm not trying to be funny: I'm absolutely serious. Isolating a studio to the levels you want is not cheap. You need to review your budget before doing anything. Two thousand pounds won't even buy the air conditioner that you will need. It won't buy the drywall. It won't buy the mass. It won't even buy the doors! Each one of the doors that you would need for that level of isolation, would set you back about £500, and you need four of them...

Link to garage plan / dimensions http://imageshack.com/a/img540/1881/usoDsa.jpg

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I need the sound proofing to be really really effective so anything happening inside the studio can not be heard outside as the garage is only 3m away from my neighbours extension and they always leave their windows open.

So let me get this straight: you want to have a live rock band playing loudly in your garage, and you want that to be dead silent 3 meters away, and you want to do that for 2 grand, and you want to start building tomorrow.

Can you see just how insane that sounds, when summarized like that?

I'm sure you did not want to hear this at all, but this is just absolutely impossible, unattainable, unrealistic, and unfeasible. You are asking for an overnight design to isolate a tiny garage to an extreme level with about 80 dB of isolation, and you want to build it tomorrow, and you want it done for two thousand pounds.

This is not going to happen. It is beyond unrealistic. It is ludicrous.

Image showing location of garage in relation to my neighbours house http://imageshack.com/a/img903/9899/tiFCkw.jpg

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Link to my initial ideas for soundproofing the walls http://imageshack.com/a/img540/4181/81mpNH.jpg

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Link to my initial ceiling design http://imageshack.com/a/img537/5895/xo8H3W.jpg

"404 Not Found"

The last part of the puzzle was how to soundproof the studio ceiling and garage roof. Initially I wanted to add mass with sand bags, but the roof joists would not have support that amount of weight.

With true Room-in-a-room construction, the roof does not support the load of the inner-leaf ceiling. The inner-leaf walls support the inner-leaf ceiling, and if you use concrete block walls, you can put one hell of a load on those, provided that your ceiling joists are dimensioned to handle the load. Even so, I would not use sandbags to add mass: how would you seal between them? Air-tight seals are just as important as mass.

Plain old drywall has plenty of mass. Two or three layers of that would get you where you want to go... provided that the outer leaf has similar mass (surface density), and that the air gap between them is large enough.

The plan was to instead use 3 layers of plaster board attached to a frame,

Right.

all bonded with green glue

Green Glue is NOT an adhesive it does NOT bond anything to anything. It is a highly specialized acoustic damping compound, that works on the principle of constrained layer damping. It is a visco-elastic polymer that never hardens, and cannot be used to "bond" things together. I wish they would never have used the word "glue" in the name of their product, because it leads to major confusion: It is not glue.

One case of Green Glue sells for around 200 pounds. You will probably need 5 or 6 cases to do what you want. There goes more than half of your budget. And that's just for the ceiling...

I would then use a double layer of dense/thick ply or chip board to add mass to the garage ceiling and cover with insulation.

Why? You don't think that 540 kilograms of drywall is going to be enough mass? Are you saying that 30 kg/m2 is insufficient? Why do you think you need more mass on the ceiling?

that's as far as I had got and I hadn't finalised the dimensions on the control room and ISO booth but after lots and lots of research (and reading this forum) I don't think my designs and sound proffing ideas were ideal!!!

Many acousticians prefer to not use the term "soundproofing", because technically, there is no such thing! Any sufficiently loud sound will penetrate any conceivable barrier. We prefer to talk about "isolation", and measure it in decibels, which is a logarithmic scale. A typical house wall gives you about 30 dB of isolation. A full rock band produces about 120 dB(C). You need to get that down to a level that does not disturb your neighbors, 3 meters away, which is probably around 40 dB. So you need to isolate to 80 dB. That is a very, very VERY tall order!

Let me put it in perspective for you. If you need to block an extra 10 dB, then in terms of sound intensity, you need to block ten time as much energy. Every time you increase your isolation by ten dB, you must block ten times more energy.

So if you have a typical house wall that isolates to 30 dB, and you want to increase that to block 40 dB, that means you have to block ten times as much sound energy. And if you wanted to increase your isolation from 30 dB to 50 dB, that means you need to block one hundred times as much energy. But if you want to increase from 30 to 60 dB, that means you need to block one thousand times as much: Increasing from 30 to 70 dB, means you need to block ten thousand times the amount of energy. And going from 30 dB to 80 dB (what you want to do), means that you have to block one hundred thousand times the amount of energy that your typical house wall blocks.

Do I have your attention now?

Because that is what you are asking.

A wall that isolates to 80 dB must reduce the sound intensity by a factor of 100,000 times. Five orders of magnitude. One hundred thousand times. This is simple math, and you can check it for yourself.

This is not something you can do overnight, with a budget of 2 grand. This takes very careful planning, lots of calculations, a huge amount of mass in both leaves, a floated isolated slab, and a budget many, many times what you have. Even then, it's probably that you wouldn't get much more than about 70-something dB of isolation, if you are very lucky. That's about the practical limit for project studios, even when built to extremes.

I'm now going to scrap the concrete block idea and go with a room within a room built from 2 leaf stud walls as that would make for a quicker build and also keep the cost down.

To get 80 dB of isolation, each of your leaves would need to be 15cm thick reinforced concrete, and there would have to be a 35 cm air gap between the, filled with fiberglass insulation having a gas flow resistivity of around 12,000 rayls. That would get you close.

My main worry with the space is the size and I need to try and loose as little space as possible to soundproofing

Then yous should forget about concrete, and make each leaf of lead plate. Each leaf would only need to be 2cm thick lead, and you could reduce the air gap to about 20 cm. That would eat up a lot less space. The price would be a lot higher, though.

I've discovered today the garage sits on a concrete base that is 1ft in depth

That's unlikely, unless it was a garage for heavy military vehicles! No garage needs a slab 30cm thick. What you probably measured was the depth of the foundations (footers), around the edge of the slab, not the slab itself. I doubt that is much thicker than 4 or 5 inches, max.

I think this will give me enough mass to get away without having to put a floating floor in?

For 80 dB of isolation, you WILL need to float your room. Not just your floor: your entire room. Your inner-leaf floor would be a thick concrete slab, and your inner-leaf walls would rest on top of that. The entire thing would rest on top of purpose-built isolation springs. The engineering calculations would take days to figure out.

My last concern is my layout and I'm considering swapping around the ISO booth and control room so the booth is at the end of the garage where the entrance door is (although this is the end that backs onto the main road).

Your photos are not visible at the location you gave, and it is a violation of forum rules to do that anyway, so we can't see what you are talking about. Please re-post your photos in the manner mentioned in the rules.

I'm sure there is a better way to split the space up rather than into 2 rectangles rooms

Quite likely, yes. But studio design takes weeks, not hours. Just designing the HVAC system alone for a studio that needs to isolate to 80 dB is going to take a few weeks.

as I think there should be some kind of sound lock at the entrance separating the main door, control room and iso booth?

Why? If the studio is designed properly, the doors on the control room and/or iso booth would do the job. Those will be paired back-to-back doors, immensely heavy, with major seals all around the edges, but if done right, they could give you the isolation you are looking for.

Any advice would be appreciated as I'm now frantically reading up all the information I can find on the internet.

To be brutally honest, my advice to you right now would be simply: Don't.

Do not try to do this. You do not have a plan, you do not have the budget, and you do not really understand what you are doing.

Call your contractor, tell him there has been a change of plans, and that the studio construction has been postponed for several months. Then I'd suggest you buy and read two books: "Master Handbook of Acoustics" by F. Alton Everest (that's sort of the Bible for acoustics), and "Home Recording Studio: Build it Like the Pros", by Rod Gervais. That will give you the basics you need to know so you can understand the issues. Then take a coupe of months to learn more about acoustics, so that you fully understand the problem of high levels of isolation and how to accomplish that, and another couple of months to learn the construction techniques that you will need. Then take about three or four months to actually design the place, taking great care to ensure that you have thought of everything, including how to achieve extreme levels of isolation on all your doors and windows, the electrical system, and the HVAC system, in addition to your walls, floors and ceilings. Then you will need to hire a structural engineer to confirm, that what you have designed actually can be built safely. Then you will need to get your permits from the relevant authorities. Then you can call your contractor again, and ask him to quote you for actually doing it.

That would be my advice. Doing anything at all like you have outlined would be immensely foolhardy.

If anyone could point me towards any plans for 2 room studios of a similar size that I could use for inspiration and ideas that would also be really helpful.

There are hundreds of examples, right here on the forum. Check out the "Studio Design" section, for completes projects. And of course, look at John's own design section, where he showcases his many successful projects.

I'm sure you did not want or expect to hear any of the above, but this is real-life, and those are realistic, feasible, achievable time lines and goals. Yours are not. There simply is no way on earth that you can start building a studio to isolate 80 dB on a budget of 2K, tomorrow morning.

Please, do not even try. You will be wasting your money, and you will achieve nothing.


- Stuart -

Hi Stuart thanks for the long reply, I appreciate your feedback and how much time it must have taken but I think you may have misunderstood me some what, so I'll add a little more detail.

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

Sorry I thought I'd covered everything

Today my builder has visited me to say he has had a job cancelled and he will be here in the morning to make a start on my new studio. The only problem is I wasn't expecting the work to start for another month or so and I still haven't finalised any of my ideas or plans!!!!

Well, this just is not in the least realistic, feasible, or even possible. Sorry. Not even close. Not even VAGUELY close. I don't mean to be insulating, but this reads something like a joke in poor taste.

The very fastest I have ever managed to complete a design for a garage conversion of a studio, is two months. That's at the edge of realistic. Overnight? Nope. Not even in Hollywood.

This is certainly not a joke and I wasn't looking for an overnight solution, as I stated in my first post my builder is starting work on re-tiling the roof first and then will move onto bricking up the garage door which has bought me a little more time. I have been planning this conversion since October and have worked through a number of designs but after a lot of reading over Christmas I decided it would be far better to go with stud and plasterboard construction for the room within a room rather than than concrete block walls as I had planned.

I've just renovated a house that has a small garage (18.24 Sq Ft)

Eighteen square feet? That's about the size of my guest toilet. Three feet wide by six feet long. Eighteen square feet. Something is waaaaay wrong here.

My apologise that should have been 18.24Sq M or 196Sq Ft

I've got a limited budget of £2000 for materials and I hope to include fixtures, fittings, doors and home made acoustic treatment in with that price but I will stretch to a little bit more if I need to.

There seems to be a zero or two missing on the end of your budget. And the "2" should probably be an "8". I'm not trying to be funny: I'm absolutely serious. Isolating a studio to the levels you want is not cheap. You need to review your budget before doing anything. Two thousand pounds won't even buy the air conditioner that you will need. It won't buy the drywall. It won't buy the mass. It won't even buy the doors! Each one of the doors that you would need for that level of isolation, would set you back about £500, and you need four of them...

I understand this is a small budget but I've already priced the plasterboard which comes in at £1000 with one outer layer and 2 inner layers. My previous control room was 4 times the size of this build and that cost just under 8k to build including tonnes and tonnes of sand that were under the floor and all fixtures and fittings. I am open to all your advice though if after reading this reply you really think what I'm trying to achieve isn't possible on my budget, I can stretch to a little more if required.

I need the sound proofing to be really really effective so anything happening inside the studio can not be heard outside as the garage is only 3m away from my neighbours extension and they always leave their windows open.

So let me get this straight: you want to have a live rock band playing loudly in your garage, and you want that to be dead silent 3 meters away, and you want to do that for 2 grand, and you want to start building tomorrow.

Can you see just how insane that sounds, when summarized like that?

I'm sure you did not want to hear this at all, but this is just absolutely impossible, unattainable, unrealistic, and unfeasible. You are asking for an overnight design to isolate a tiny garage to an extreme level with about 80 dB of isolation, and you want to build it tomorrow, and you want it done for two thousand pounds.

This is not going to happen. It is beyond unrealistic. It is ludicrous.

You must have misread my original post as there is no intention to record a full rock band in the garage, there just wouldn't be space for that and I'm aware that would be way too loud for me to isolate on my budget. I'm looking to build a control room for mixing and a ISO booth for vocal overdubs and I'd also like to occasionally mic up a guitar amp in there too (there would be a tie line into the booth so the guitarist would be in the control room). I should have maybe worded that differently and said I know I won't be able to make it absolutely silent but I would be looking to substantially reduce the amount of sound coming in and out of the studio.

Image showing location of garage in relation to my neighbours house http://imageshack.com/a/img903/9899/tiFCkw.jpg
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That's strange the links are working fine on my computer and my tablet, they are over 700 pixels so I didn't want to post them directly to the forum. I'll resize them and then post them again.

The last part of the puzzle was how to soundproof the studio ceiling and garage roof. Initially I wanted to add mass with sand bags, but the roof joists would not have support that amount of weight.
With true Room-in-a-room construction, the roof does not support the load of the inner-leaf ceiling. The inner-leaf walls support the inner-leaf ceiling, and if you use concrete block walls, you can put one hell of a load on those, provided that your ceiling joists are dimensioned to handle the load. Even so, I would not use sandbags to add mass: how would you seal between them? Air-tight seals are just as important as mass.

Plain old drywall has plenty of mass. Two or three layers of that would get you where you want to go... provided that the outer leaf has similar mass (surface density), and that the air gap between them is large enough.

This wasn't part of the studio ceiling this was added mass I was planning on adding over the current roof joists in the garage which would have been clearer if the links to my diagrams had worked

A full rock band produces about 120 dB(C). You need to get that down to a level that does not disturb your neighbors, 3 meters away, which is probably around 40 dB. So you need to isolate to 80 dB. That is a very, very VERY tall order!

Let me put it in perspective for you. If you need to block an extra 10 dB, then in terms of sound intensity, you need to block ten time as much energy. Every time you increase your isolation by ten dB, you must block ten times more energy.

A wall that isolates to 80 dB must reduce the sound intensity by a factor of 100,000 times. Five orders of magnitude. One hundred thousand times. This is simple math, and you can check it for yourself.

This is not something you can do overnight, with a budget of 2 grand. This takes very careful planning, lots of calculations, a huge amount of mass in both leaves, a floated isolated slab, and a budget many, many times what you have. Even then, it's probably that you wouldn't get much more than about 70-something dB of isolation, if you are very lucky. That's about the practical limit for project studios, even when built to extremes.

It's not a full rock band I'm trying to isolate as the control room will be for mixing and the ISO booth for vocals and occasionally micing up a guitar. I wanted to be able to fit 4/5 people in the control room comfortably for attended mix sessions, if possible it would be great if I could get a design that worked and gave me enough space in the ISO booth to fit in a guitarist and acoustic guitar but that's not essential.

My main worry with the space is the size and I need to try and loose as little space as possible to soundproofing
Then yous should forget about concrete, and make each leaf of lead plate. Each leaf would only need to be 2cm thick lead, and you could reduce the air gap to about 20 cm. That would eat up a lot less space. The price would be a lot higher, though.

Plasterboard construction is going to be the only way forward for me and plasterboard is much cheaper than block work in the UK so it should be cheaper or is it the green glue that will add to the overall price? My last studio didn't have green glue between the walls (I didn't build it, it was the previous tenant) and the soundproofing was very effective although not perfect.

I think this will give me enough mass to get away without having to put a floating floor in?
For 80 dB of isolation, you WILL need to float your room. Not just your floor: your entire room. Your inner-leaf floor would be a thick concrete slab, and your inner-leaf walls would rest on top of that. The entire thing would rest on top of purpose-built isolation springs. The engineering calculations would take days to figure out.

It was a thread I read on this site that made me think I wouldn't need a floating floor, before reading that thread the plan was always to build the whole structure on top of a floating floor (again my apologies as that wasn't clear without my diagrams showing)

I'm sure there is a better way to split the space up rather than into 2 rectangles rooms
Quite likely, yes. But studio design takes weeks, not hours. Just designing the HVAC system alone for a studio that needs to isolate to 80 dB is going to take a few weeks.

I wasn't going to go with a HVAS system as I have a portable AC unit I was planning on using in the control room.

as I think there should be some kind of sound lock at the entrance separating the main door, control room and iso booth?
Why? If the studio is designed properly, the doors on the control room and/or iso booth would do the job. Those will be paired back-to-back doors, immensely heavy, with major seals all around the edges, but if done right, they could give you the isolation you are looking for.

Again this is another idea I had come up with after looking at other peoples designs on this forum.

Any advice would be appreciated as I'm now frantically reading up all the information I can find on the internet.
To be brutally honest, my advice to you right now would be simply: Don't.

Do not try to do this. You do not have a plan, you do not have the budget, and you do not really understand what you are doing.

Call your contractor, tell him there has been a change of plans, and that the studio construction has been postponed for several months. Then I'd suggest you buy and read two books: "Master Handbook of Acoustics" by F. Alton Everest (that's sort of the Bible for acoustics), and "Home Recording Studio: Build it Like the Pros", by Rod Gervais. That will give you the basics you need to know so you can understand the issues. Then take a couple of months to learn more about acoustics, so that you fully understand the problem of high levels of isolation and how to accomplish that, and another couple of months to learn the construction techniques that you will need. Then take about three or four months to actually design the place, taking great care to ensure that you have thought of everything, including how to achieve extreme levels of isolation on all your doors and windows, the electrical system, and the HVAC system, in addition to your walls, floors and ceilings. Then you will need to hire a structural engineer to confirm, that what you have designed actually can be built safely. Then you will need to get your permits from the relevant authorities. Then you can call your contractor again, and ask him to quote you for actually doing it.

That would be my advice. Doing anything at all like you have outlined would be immensely foolhardy.

Unfortunately putting off my builder isn't an option and we have decided we will make a start on the garage studio, but focusing on the garage roof and bricking up the garage door first. I won't get him to start any of the internal work until I know I have a fool proof plan / design.

All your points are very. valid and I was looking for advice on the soundproofing and studio design. Although I have worked in many great studio I'm an engineer not an acoustician and my strong points certainly aren't acoustics and studio design but I think you may have misunderstood what I'm trying to achieve which is due to my poor descriptions and the diagrams not working.

I also forgot to mention in preparation for the build I have made 3 heavyweight doors, my electrical system has been planned out by a qualified electrician and I have already had power run into the garage.

As I've now decided to go with a plasterboard construction and the garage won't be a living space I can do this without a permit and the work inside the garage just has to be inspected at various stages of the build by our local authorities building inspector.

This image shows the dimensions of my garage This image shows the proximity of the garage to my neighbours house These are the old plans I had for soundproofing the space but this is NOT how I will be soundproofing now after further research. I now plan to go with a 2 leaf design using resilient bars if that will give me substantial enough STC rating to reduce the sound of a control room and ISO booth that's intended for mixing, recording vocals and guitar amps.

Old wall design and how the garage would be split Old ceiling diagram (which is missing the ceiling joists that would have been supported by the stud) So my questions are:
1) After explaining in more detail what I'm looking for is my budget for materials still really unrealistic?
2) Would a 2 leaf design offer isolation?
3) Would I need a floating floor as my garage sits on a deep concrete base?
4) Is there a better design for the garage than 2 rectangle rooms to get the most out of the space?

Hi Pies,

I mean this post to be as useful to you as possible, not critical, but I think I can answer one question.

I am currently constructing a mix room with no iso booth in a single garage in the UK, so similar situation. I am building it all myself with only a couple of days of hired handy man help so far, and I can tell you that your £2k budget will get you nowhere near finished. I have meticulously sourced the cheapest materials, spending hours, to get the most out of my budget, and I am still around the £7k mark for my small build.

If you think about the plasterboard, insulation and Green Glue alone, that will take you over the £2k mark alone. I would consider finding a loan or extra funds if you want a workable/not unfinished space.

Hope that is of some help,

Adam.

After the advice given I haven't gone straight ahead with the studio build and instead I've used the time to get the roof re done, get the last window bricked up and to also raise the height of the garage by 1 block making the floor to ceiling height 2.4m.

I took a few pictures of the garage before the new roof went on to give you an idea of what I'm dealing with, please excuse the messy garden as it's the last thing on the to do list once we've finished renovating our house and I've finished the studio.
As I've had another month to research soundproofing methods and learn the basics of Sketch Up I've totally redesigned my space and it would be great if I could get your opinions on what I've come up with. I'm really keen to get my builders working on this ASAP but I need to get the design right and make sure my sound proofing is going to be effective. I can't cause a nuisance to my neighbors and I need to keep the sound of their noisy small children out of my ISO booth as they like to play (scream) in the their garden regularly. As I said in my original post the space will be used mainly to mix rock and pop music and the ISO booth will be used to track vocals and mic up guitar cabs that will be driven. I have access to a "real" studio for drum tracking as the booth is far too small to consider it for anything apart from vocal and guitar overdubs. The booth is intended to be a very very dry space. Here are some sketch ups I made.
As you can see from the Sketch Up diagrams I still plan to go for a room within a room and as I'm on a limited budget I've been researching materials and steel stud comes in way cheaper so I will be building the whole room out of that. From the STC charts I've looked at steel stud is also much better for reducing sound transmission than timber stud.

You will notice from my Sketch Up design I only plan on decoupling the outer walls of the studio from the exterior walls and the ISO booth will not decoupled from the control room, this is due to the size of the space and cost. I will attached the plaster boards on this wall to resilient bars to achieve a higher STC.

Here is a cross section of my new design for the outer walls walls, floor and ceiling:
Floor
The floor of the garage is hard concrete and very deep, I recently had my driveway block paved and the ground workers had to chip away at some of the concrete and said it's the hardest concrete they have ever come across which is great as that means I already have a whole lot of mass on the floor. I'm not 100% certain if I need to float my floor so it would be great to get some confirmation on that? If I do then I plan to make a sub frame and float it on Auralex U Boats fill the frame loosely with rock wool and then cover it with 2 layers of ply before adding a laminate floor over the top.

If a floating floor isn't needed that would be great as it would really cut down on cost and I could just run my metal stud track straight on the floor with neoprene strips underneath.

Walls
I plan on going for a 2 leaf design using 3 layers of plasterboard on either side of the steel stud with rockwool in between and from the STC charts I've read I think I should achieve a STC of around 60 which I hope combined with my exterior walls will reduce the sound coming in and out of my studio enough to be able to not have to put green glue in between the layers of plasterboard?

Ceiling
The ceiling has been the hardest part for me to design as I'm not confident steel stud would support all that plasterboard so I plan to attach the first 3 layers of plasterboard that make up the first leaf to a steel stud frame and to attach the second leaf directly to the new garage ceiling with resilient ceiling channels.

Doors
Due to the size of the space and my design it's going to be almost impossible to have double doors into each room and the external door is not a standard size. I intend to beef up the external door as it's currently solid wood with a lot more wood and make the frame as air tight as possible and inside the studio I will use fire doors which again I will add mass too with wood and again make the frames as air tight as possible.


Finally here is a diagram of the space all split up which shows the dimensions of each room. The idea behind my design is that the outside door leads into a entrance that will act as a sound lock to help with sound escaping from the building and also from a security point of view I don't like the idea of the control room being accessed from an external door.
You will see from my diagram the control room isn't the best dimensions for great acoustics but I'm hoping with large super chunks up front, bass trapping as many corners as possible and lots of broad band absorbers around the room I can make it usable. I understand this is a challenging space so I welcome any advice anyone can offer? My other concern is how small the control room will be as there will be days when myself and a band will be in there if we are tracking vocals or guitar. My sketch up is roughly to scale (within 10cm) and it appears I would fit everything in including my couch with some space to spare but the dimensions sound really tiny to me. Tomorrow I'm going to mark everything out with masking tape to make sure everything will fit.

Ventilation
Initially I had intended on using a floor standing air con unit in the control room and then making ventilation holes in the wall that vent out to baffle boxes with a extractor fan on one but after some thinking I have decided I'm going to buy a consumer air con unit that can be mounted on the wall above the sofa. A consumer unit would be fine for the size of the room and it could be vented into the loft space.


So in summary my main questions are:

1) Do my wall and ceiling designs look like they will reduce the noise coming into the studio to a workable level (without using green glue)?
2) Do my wall and ceiling designs look like they will be effective at significantly reducing the level of noise coming out of the studio so I don't cause a nuisance to my neighbors? I'd love to be able to make the studio silent from outside but I understand with my budget and the space I have available that isn't realistic.
3) Is my floating floor design any good and is it going to offer anymore isolation than if I just went ahead without it. The main reason for adding the floating floor is to try and reduce the low end transmission when I'm mixing bass heavy music or recording louder guitar amps, it was also to try and reduce the rumble of road noise from the main road in front of my house.
4) I'm a little concerned about how much space I'm loosing with my current wall construction if anyone knows of another cost effective way of attacking this and loosing less space I'm all ears?
5) Is there a better way I could set out my control room and booth to get better acoustics and make better use of the small space I have available to me?

As I've had another month to research soundproofing methods and learn the basics of Sketch Up I've totally redesigned my space and it would be great if I could get your opinions on what I've come up with.

I have to say, that's a good improvement! Nice SketchUp work, too.

I can't cause a nuisance to my neighbors and I need to keep the sound of their noisy small children out of my ISO booth as they like to play (scream) in the their garden regularly.

It would be good if you could put real numbers to those levels, by measuring with a proper hand-held sound level meter. Silencing the kids should not be a problem, since all of that is in the mid range, but silencing your own sound going out might be an issue, depending on how loud you are and how quiet you need to be (measured in decibels).

The booth is intended to be a very very dry space.

It will have to be, for that size. Rather then dry, it will need to be dead. Dry implies a little bit of very short reverb in the mids and upwards, but the room is probably too small for that, so your best bet is to just make it totally dad, all around.

Here are some sketch ups I made.

The basic layout is reasonable, but with caveats... The first thing I would suggest is turning the CR around so it faces the booth, and you have good visual sight lines between the two. Having the booth behind you means that you'll be spinning around 180° and back all the time while tracking.... or you won't turn at all, due to the effort, in which case the glass is a bit if a waste! I would aim for a design where there is direct straight visual contact between rooms. That messes up your entry sound lock, but that is wasted space anyway. It would be nice to have that to get independent doors to the two rooms, but to be honest in such a small space it would be better to use it all for actual acoustic areas, and sacrifice the comfort of the separate entry paths. That would mean that you'd need a door directly from the CR into the booth, but that isn't a bad idea anyway. It would also allow you to put the exterior door in a more usable location, such as the middle of a side wall in the CR, or the middle of the rear wall. Where you have it right now, in the rear corner of the CR, is a big problem because that's exactly where you need to put some major bass trapping. Corners are prime real-estate for acoustic treatment, simply because that's where all the room modes terminate.

Also, your diagram shows good isolation between the rooms as a set and the outside world, but not good isolation between the rooms. You only have a single-leaf wall between the CR and booth, so there won't be a lot of isolation there. Probably not an issue for vocals, but it could be a problem of you are using that booth to mic an amp while simultaneously tracking vocals in the CR...

As you can see from the Sketch Up diagrams I still plan to go for a room within a room ...

Except that isn't what your detailed diagrams show! They show "room in a room in a room": Three-leaf. Bad idea. That will not get you good low-frequency isolation...

From the STC charts I've looked at...

Careful with STC! It is no use for measuring studio isolation. STC is a single-number indicator of sound isolation for a small part of the audio spectrum, roughly in the area where speech occurs, as well as typical office and house sounds. It tells you nothing at all about how well a wall will isolate music. STC does not take into account the bottom two and a half octaves of the spectrum, nor does it take into account the top two and a half octaves of the spectrum.... I can build you a wall rated at STC-50 that has lousy isolation for loud rock music, and I can built you another wall rated at STC-35 that does much, much better at isolating loud rock music... Don't rely on STC for designing your isolation system! Instead, look at the full TL graphs, and compare those to the graph of your own isoaltion needs.

You will notice from my Sketch Up design I only plan on decoupling the outer walls of the studio from the exterior walls and the ISO booth will not decoupled from the control room, this is due to the size of the space and cost.

If you correct your design, you will find that you have a lot more space, and a lot less cost!

I will attached the plaster boards on this wall to resilient bars to achieve a higher STC.

Not with the layout you are showing in your detailed diagrams! You would actually get rather poor isolation for low frequencies like that...

Especially from your ceiling! That is a FOUR-leaf system, with three very thin air gaps! The MSMSMSMSM resonance of that system would be hell to calculate (three resonant systems interacting! ), so I won't even try, but I can tell you that it would be high... and therefor he LF isolation would be lousy. You can get vastly superior isolation for a lot less money and in a lot less space, by going with conventional two-leaf construction. Even though you have large amounts of mass on three of those leaves, the tiny air gaps between them and the simply fact of having 4 leaves will skew the TL curve way up the spectrum, to places you don't want it to be.

One other point about your ceiling: Did you check the structural loading calculations for that? To me it looks like you are severely overloading your joists... At a rough guess, you'd need 2x10 joists to carry a load that huge (50 x 250mm section).

Your walls are only slightly better, as they are 3-leaf, not 4-leaf, but still far short of where they could be if you did them properly as 2-leaf.

Then there's the light-weight attempt at a floating floor. Oh dear.... You probably should read this:

http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173

Hopefully that will set you straight on what to do about that floor: lose it! You do NOT need it, it will do more harm than good, and it also wastes a chunk of your very limited headroom. Just stay with the plain concrete slab, if it is in good shape, or if not then lay simple ceramic flooring, or laminate flooring. Both are very thin (no loss in headroom) and leave you with an acoustically excellent floor that will not damage your isolation or room acoustics in the multiple ways that a light-weight floated floor would.

The floor of the garage is hard concrete and very deep,

Excellent! Done deal. Nothing more needed. Perfect isolation couldn't be better, literally), and perfect acoustics for a studio floor.

said it's the hardest concrete they have ever come across which is great

Yes it is! Even more reason to not trash it with a "floating" floor that won't actually float...

I'm not 100% certain if I need to float my floor

I'm 100% certain that you don't! And that floor you show isn't even floated properly anyway. In the above thread you'll learn why.

If a floating floor isn't needed that would be great as it would really cut down on cost and I could just run my metal stud track straight on the floor with neoprene strips underneath.

You were perfectly correct, and doing fine, until you got the last three words of that sentence.... "neoprene strips underneath". Why? Why do you want to incur that extra expense for no discernible reason? Contrary to popular internet myth, putting rubber under your walls does nothing at all to float them. You still have to anchor your walls to the floor, with large nails or bolts, which penetrate right through the rubber, thus "short-circuiting" it, and creating flanking paths. There is no "float" like that, so it is wasted time and money and effort: The ONLY reason you might want rubber under there is if the concrete is in really lousy state: cracked, pitted, uneven, flaking, etc., so badly that you can't get a good seal any other way. And if that's the case, it would be better to just scrape the concrete and put a layer of self-leveling cement on top, to fix that, before you put up your inner-leaf walls.

I plan on going for a 2 leaf design

... but you ended up going for a three-leaf design! Why the change in plans?

using 3 layers of plasterboard on either side of the steel stud

That is a coupled two-leaf wall: Add that to the existing building shell, and you have a 3-leaf wall: lousy isolation in low frequencies.

from the STC charts I've read I think I should achieve a STC of around 60

Unlikely, for several reasons, ... plus the comments above about STC not being suitable for measuring studio isolation...

which I hope combined with my exterior walls

... will make a three-leaf wall, that REDUCES low frequency isolation, as compared to a thinner wall built with less mass that would get you BETTER isolation if it were just a proper fully decoupled two-leaf system.

enough to be able to not have to put green glue in between the layers of plasterboard

Green Glue is nice if you can afford it, but is not a magic bullet, nor is it an absolute necessity. You can indeed build a well isolated studio without it.

The ceiling has been the hardest part for me to design as I'm not confident steel stud would support all that plasterboard

You are correct: it would not. But your solution creates a 4-leaf system, with multiple thin air gaps, and therefore very poor low frequency isolation.

attach the second leaf directly to the new garage ceiling with resilient ceiling channels.

... thus creating a very thin air gap with a very high resonant frequency in the middle of your 4-leaf system, and also using resilient channel in a manner that was never intended by the manufacturer, and likely contrary to what your building code allows anyway...

Due to the size of the space and my design it's going to be almost impossible to have double doors into each room

... on the other hand, if you change the layout around as I suggested above, that would no longer be an issue: there would be space for that on both the single external door, and you could use a pair of back-to-back sliding glass doors between your CR and booth, or a pair of back-to-back hinged doors with glass in them, which obviate the need for an additional window, and give you good sight lines and good isolation....

My other concern is how small the control room will be

... It could be a bit bigger if you forget about the extremely massive three-leaf walls, and instead just do a traditional two-leaf wall. You already have a substantially massive outer leaf (concrete block) so your inner-leaf doesn't need to be extremely massive either, and the air gap can be reasonable. My guess is that you'd save a dozen cm in each direction like that.... not a huge amount, but still very decent. And with such a small building, every cm counts.

... after some thinking I have decided I'm going to buy a consumer air con unit that can be mounted on the wall above the sofa.

That takes care of the "H" and "AC" parts of HVAC, but leaves out the rather important "V"! You are talking about a mini-split system by the sounds of it, which is fine, and is a very good choice for small project studios (provided that it is dimensioned correctly!), but all it does is cool or heat the air. It does not ventilate. you still need a ventilation system, in addition to the mini-split. The ventilation system provides you with fresh air (ie, oxygen) so you and your buddies can breathe and stay alive while you jam and track and mix, and it also provides an exit path for the stale air (ie, CO2 and other noxious gases) that would otherwise build up in the room and stop you from staying alive...

So ventilation is sort of important, if you plan to stay alive inside the room. With such a small space and several musicians shoe-horned in, the air will become pretty nasty in rather short order. Ventilation is not an "option", or a luxury: it is a basic necessity.

However, ventilating a room with the required air volume (8 room changes per hour) at a slow enough air flow speed (under 300 FPM), implies chopping a pair if huge holes in your isolation walls. But you have no choice: you MUST do that. To stay comfortable and conscious. So you need to put silencer boxes on the wall penetrations, where the ducts pass through each leaf. For each room. (You cannot share silencers between rooms, for obvious reasons). Those boxes are BIG. You have no space for them inside the already tiny rooms. I would suggest either putting them outside the exterior walls, or in the attic space (which is another problem entirely....)

it could be vented into the loft space

No it could not! Most certainly not! Do you REALLY want to pump warm moist, humid air into your ceiling space? Do you really want to rot your ceiling and roof from the inside?

Also, you seem to be unaware of how a mini-split system actually works: The unit you hang on the wall is only half of the system. That's the evaporator unit, that contains only a fan and a small "radiator"-like thingy that the air passes through to cool it. The MAIN part of the system is the external condenser unit, which contains the compressor, a much larger fan, and another "radiator" thingy. The two units are joined by a bunch of pipes and cables. The condenser unit sits outside in your garden someplace, on the ground, on the wall, on the roof, but NEVER inside the attic space.

1) Do my wall and ceiling designs look like they will reduce the noise coming into the studio to a workable level

No.

2) Do my wall and ceiling designs look like they will be effective at significantly reducing the level of noise coming out of the studio so I don't cause a nuisance to my neighbors?

No.

I'd love to be able to make the studio silent from outside but I understand with my budget and the space I have available that isn't realistic.

There's actually no such thing as "silence" (except in space, where nobody can hear you scream... . Even the most silent room on the planet (the recently certified anechoic room at Microsoft), there is still measurable noise, at around -24 dBA. Way too quiet for humans to hear, of course, but still not "silent", in the true technical sense. That's why acousticians and studio designers don't usually use the word "soundproofing", since there is no such thing! Any sufficiently loud sound will penetrate any conceivable barrier. The loudest sound ever to occur on planet earth was heard around the other side of the planet!

So yes, "silence" is out of the question. However, substantial isolation is possible, and feasible, if you design and build it correctly. But "substantial" is a subjective term, and you need an objective term. You need to measure your actual sound levels, in dBC, and check how quiet you need to be (both legally and reasonably), then calculate how much isolation you need, in dB, and design / build the studio accordingly.

3) Is my floating floor design any good

No.

is it going to offer anymore isolation than if I just went ahead without it.

Less, in fact. At best, there would be no difference in isolation, but you'd still have the resonant issues....

The main reason for adding the floating floor is to try and reduce the low end transmission when I'm mixing bass heavy music or recording louder guitar amps,

It would likely INCREASE that, since it would be tuned to that very frequency range...

it was also to try and reduce the rumble of road noise from the main road in front of my house.

That's not going to happen with a very low-mass, light-weight flexible deck sitting on a small air cavity.... That would require a massive concrete deck sitting on proper isolation mounts, tuned to a frequency at least one octave lower than the frequency of the rumble. That's a job for careful acoustic and vibration analysis, proper calculation and design, and correct engineering and construction of the solution. It could be done, but not simply, and not cheaply. You didn't mention your budget, but likely the floor would eat up the entire budget, and more, of you were to float it properly such that it truly does isolate low frequency traffic vibration.

4) I'm a little concerned about how much space I'm loosing with my current wall construction if anyone knows of another cost effective way of attacking this and loosing less space I'm all ears?

Do it with normal 2-leaf fully-decoupled MSM isolation, tuned an octave below the lowest frequency you need to isolate (airborne sound), using high density materials to save space. Design it and calculate it it correctly using the usual equations, with proper consideration for HVAC and electrical systems, and you will likely gain quite a bit of space. I mentioned above that I think you can gain at leas a dozen centimeters on each wall, and perhaps more if you do the calculations right and choose the best materials for the highest mass in the least space, with the smallest air gap that provides the needed f0 frequency and transmission loss.

5) Is there a better way I could set out my control room and booth to get better acoustics and make better use of the small space I have available to me?

Yes. I think I already covered that above: Turn things around so the CR faces the LR, dump the entry sound lock (which you do not need), and design the walls (and ceiling) correctly to minimize space while maximizing isolation at the frequencies you need it. That does mean that your entry door would be in the side or back of the CR, where it belongs, but you did say you didn't like that due to the security issue. I'm wondering why you think it would be more secure with a sound lock!!! ??? If a burglar gets through your external door, then he is in your studio already, and you are screwed already! The sound lock would make zero difference, except that it would give him a nice staging area to work on the other doors, out of sight, and to carefully accumulate and sort through all the good stuff while deciding what to take and what to leave, warm and dry, protected from the elements, and from being seen and heard.... You actually make his job easier by providing that nice lobby for him to work in...

Just put a door in the middle of the back wall of the CR. There will be two doors there anyway (back-to-back, one in each leaf), so if you want high security, make them both heavy fire doors with substantial locks: if he does manage to get through the first one after some hard work (out in the open, highly visible), and then comes across a second equally tough door right in front of him, still out in the open and visible, he'll likely give up and go elsewhere. Security is not about making a place impenetrable: it's about making it unattractive for the potential thief, and dissuading him from proceeding. Forget the false security and wasted space of the sound lock, and re-arrange the layout so it makes more sense acoustically, visually, and practically.

- Stuart -

Hi Stuart, thanks for taking the time to reply and the invaluable information.

I've realised I was getting confused between 2 leaf and 3 leaf systems and that each side of a stud wall counts as a leaf so I've redesigned the walls. Would my new design now constitute a 2 leaf system and be more effective at reducing the amount of low end being heard outside of the studio?
I'm also going to paint the inside of the block work to seal it all and I'm wondering if adding insulation to the block work would be of any benefit as my design currently just has a layer of insulation up against the plasterboard?

I've got rid of the floating floor as I don't feel it would be needed due to the heavy concrete the garage is sat on and as you pointed out the low budget option I was looking at would potentially cause more issues.

I've tried to make the ceiling a 2 leaf design too but unfortunately it's going to be impossible as we need to use the roof space for storage but I have managed to get it down to 3 leaves. Would this improve the bass transmission from the ceiling of the studio?

Soundman2020 wrote:The first thing I would suggest is turning the CR around so it faces the booth, and you have good visual sight lines between the two. Having the booth behind you means that you'll be spinning around 180° and back all the time while tracking.... or you won't turn at all, due to the effort, in which case the glass is a bit if a waste! I would aim for a design where there is direct straight visual contact between rooms. That messes up your entry sound lock, but that is wasted space anyway. It would be nice to have that to get independent doors to the two rooms, but to be honest in such a small space it would be better to use it all for actual acoustic areas, and sacrifice the comfort of the separate entry paths. That would mean that you'd need a door directly from the CR into the booth, but that isn't a bad idea anyway. It would also allow you to put the exterior door in a more usable location, such as the middle of a side wall in the CR, or the middle of the rear wall. Where you have it right now, in the rear corner of the CR, is a big problem because that's exactly where you need to put some major bass trapping. Corners are prime real-estate for acoustic treatment, simply because that's where all the room modes terminate.

This is how I had initially planned to lay out the studio but unfortunately there wouldn't be enough space to get around my desk and equipment to a door so the only option I can see is to have the booth where it currently is?

Soundman2020 wrote:Also, your diagram shows good isolation between the rooms as a set and the outside world, but not good isolation between the rooms. You only have a single-leaf wall between the CR and booth, so there won't be a lot of isolation there. Probably not an issue for vocals, but it could be a problem of you are using that booth to mic an amp while simultaneously tracking vocals in the CR...

The isolation between the 2 rooms could be improved but it would be at the expense of loosing more space so I intend to use one frame here and mount the plasterboard on resilient bars. I don't intend to use each room simultaneously for recording and there would only ever be an amp or person in the booth whilst I monitor in the control room.

Soundman2020 wrote: One other point about your ceiling: Did you check the structural loading calculations for that? To me it looks like you are severely overloading your joists... At a rough guess, you'd need 2x10 joists to carry a load that huge (50 x 250mm section).

All my stud frame is now going to be wood so the inner ceiling (plasterboard) will now be supported by the stud walls which means the roof joists will only support the chipboard in my new design.

Soundman2020 wrote: You already have a substantially massive outer leaf (concrete block) so your inner-leaf doesn't need to be extremely massive either, and the air gap can be reasonable. My guess is that you'd save a dozen cm in each direction like that.... not a huge amount, but still very decent. And with such a small building, every cm counts.

Today my builder called round to have a look at the plans for the studio so far and he has suggested to not use block work in front of the garage door and instead put in a stud wall as it would be easier to undo if I wanted to turn the space back into a garage in the future. He is suggesting to just use a frame tight up to the door and use a few layers of plaster board over the top instead as it will save on space but I fell this will massively reduce the effectiveness of my design. Is there anyway I could use a stud wall in front of the garage door that would be as effective as block work? ( maybe using MDF or some kind of wood instead of plasterboard if that would give me more mass) Loosing less space is really appealing.

Would my new design now constitute a 2 leaf system and be more effective at reducing the amount of low end being heard outside of the studio?

Much better!

I'm also going to paint the inside of the block work to seal it all and I'm wondering if adding insulation to the block work would be of any benefit as my design currently just has a layer of insulation up against the plasterboard?

Filling the entire air gap with insulation is a good idea: it maximizes isolation. Just don't force it in too tightly. In other words, don't compress the insulation too much. Just put it in place. It can touch all the surfaces, as long as it is not compressed. Also, do check your local fire code to make sure that is allowable.

I've got rid of the floating floor

I've tried to make the ceiling a 2 leaf design too but unfortunately it's going to be impossible as we need to use the roof space for storage but I have managed to get it down to 3 leaves. Would this improve the bass transmission from the ceiling of the studio?

sometimes you have no choice, and you have to build a 3-leaf system. That's fine, provided that you take the necessary precautions and adapt the design to compensate for the lost isolation. 1) put more mass on the "middle" leaf. Ideally, the middle leaf by itself should have the same mass as the other two leaves combined. That might not be possible in practice, but definitely put as much as you can on the middle leaf. 2) Increase the sizes of the two air gaps on either side of the middle leaf. 3) Put s much insulation in there as you can, filling the air gaps if possible, or at least getting a good thickness in.

there wouldn't be enough space to get around my desk and equipment to a door

re-arrange the desk and equipment! Make the desk smaller, put some of the gear in racks under the desk, or embedded into the desk surface.

You are gaining about 30 cm in room width in any case, as compared to what you would have had originally, so you don't need too much more space to be able to get past your desk and gear.

The isolation between the 2 rooms could be improved but it would be at the expense of loosing more space so I intend to use one frame here and mount the plasterboard on resilient bars.

You could do it that way, but it would be better to do it properly.... Here too you are already gaining over 30 cm in total length, so there should be space to do it right now...

All my stud frame is now going to be wood so the inner ceiling (plasterboard) will now be supported by the stud walls which means the roof joists will only support the chipboard in my new design.

Great, but you still need to check the span tables and load carrying capacity of the joists in both places. Or if you don't know how to do that, then get a structural engineer to do it for you.

Is there anyway I could use a stud wall in front of the garage door that would be as effective as block work?

You could do it that way, yes. It won't be as effective as block, of course, but it can still be pretty good, provided you put enough mass on it, and have enough insulation in the air cavities.


- Stuart -

My build is well underway and the garage has gained in height by 1 block, it's had a new roof, the stud work is in, the electric cables have been laid and it's ready for insulation and plasterboard now.


Here are some pictures of the new block work, blocking up the garage door and the new roof.
Once the new roof had been built and the garage door and window had been blocked up the blocks were lightly skimmed (to make them easier to paint) and then painted to seal. Unfortunately as we needed the loft space for storage the ceiling is going to be 4 leaves The leaf you can see from inside the garage is 2 layers of 12.5mm plaster board and a layer of chipboard that have all been sealed with acoustic sealant. There is then soft loft insulation in between that leaf and then chipboard loft boarding above and the roof tiles are slate. I haven't sealed the loft boards as I didn't know if this would make any major difference being the 3rd leaf?
Once the block work had all been completed and sealed the studs for the inner room went up which are 1.5cm away from the exterior walls and ceiling and allow for 10cm of insulation. An electrician came in and installed a fuse box and put in all the cables for the sockets and lights (and a extra ring for the AC that I plan to put in at a later date)
Finally two 8" holes have been cut in the 2nd and 3rd leaves of the CR ready for me to install a simple ventilation system comprising of 2 baffle boxes in the loft space with piping connecting those to outside and a fan on the out take.

I've got a few questions about the next stage of my build and suitable materials?

Insulation
Originally I was going to put RWA45 Rockwool in the wall cavity but would it be better to use a lighter insulation like the fiberglass loft insulation? I've read it's better for reducing bass transmission when covered with plasterboard? Are there any downsides of using it instead of rockwool? I'd still be using rockwool for my traps and absorbers inside the rooms.

Plasterboard
I was going to use 2 layers of 16mm plasterboard on the walls and ceiling but I'm finding it hard to source. If I can only get hold of 12.5mm board and go with 3 layers would this drastically impact the amount of isolation? Also would I benefit from using different thicknesses of plasterboard for each layer as I've read that can help breakdown sound waves? The thicknesses that are currently available to me are 9.5mm and 12.5mm.

Ventilation
My ventilation system is fairly basic intake and outtake vents in the ceiling that will attach to baffle boxes with 8" tube which will then attach to 4" insulated ducting that will vent outside. I'm going to put a fan on the outtake but I don't know what fan to use? If you could point me in the right direction any help would be much appreciated.

I managed to get hold of 15mm boards in the end so I will be putting up 3 layers and sealing over the weekend.

I've got another questions regarding controlling bass in the CR. Originally I was going to make 2 super chunks and load of broad band absorbers from 100mm R45 to go around the room but I think 100mm is going to make the room feel really really small. Is there an equivalent 50mm rockwool I could use to get the same performance?

Originally I was going to make 2 super chunks and load of broad band absorbers from 100mm R45 to go around the room but I think 100mm is going to make the room feel really really small. Is there an equivalent 50mm rockwool I could use to get the same performance?

Not really: different thicknesses do different things at different frequencies. But for the same reason, don't plan on doing the entire room with identical panels! It's better to do things in stages, testing in between to see if you are getting the desired effect from each panel, seeing what still needs to be done and designing the next panel to do that.

Originally I was going to put RWA45 Rockwool in the wall cavity but would it be better to use a lighter insulation like the fiberglass loft insulation? I've read it's better for reducing bass transmission when covered with plasterboard?

The heat rating doesn't mean much fir acoustics. What you need is mineral wool whose density is around 50 kg/m3 (or 30 kg/m3 if you use fiberglass): That's the right stuff for wall cavity fill.

I was going to use 2 layers of 16mm plasterboard on the walls and ceiling but I'm finding it hard to source. If I can only get hold of 12.5mm board and go with 3 layers would this drastically impact the amount of isolation?

It would make a difference, yes, but since you have a nice solid massive outer-leaf, I wouldn't worry about it. If that's all you can get, then that will have to do. If you can afford it, add a layer of Green Glue compound between two of those layers.

Also would I benefit from using different thicknesses of plasterboard for each layer as I've read that can help breakdown sound waves?

No overall benefit, no. Yes, you do get slightly beneficial effects from having different density layers in your walls, but drywall is drywall, and the difference between 9mm ans 12.5mm is not useful. Even if it were, you'd be losing isolation from the lower mass of one layer, and perhaps running into resonance issues from the thin, light, flexible 9mm stuff. Those losses are greater than the gains. So no, it's not worth it.

I'm going to put a fan on the outtake but I don't know what fan to use? If you could point me in the right direction any help would be much appreciated.

Fantech makes good stuff that is specifically meant for this application.

Something like this:

http://www.fantech.com.au/FanData.aspx? ... Pid=EWE152


- Stuart -