John Sayers' Recording Studio Design Forum

Hi all, I have to admit to being a little out of my depth here but I've been recommended to this site by a friend of my husband's who's been helping me do some research on Studio construction. This is the situation we're in: my husband, Leigh, is a musician and writing and recording music is his escape from the Crohn's Disease he's had since he was very young. It's a very severe and aggressive form of the disease which has seen him have to have over 10 major operations, on heavy duty painkillers every day and with limited medical options left open to him. Because of this, he's about to enter a combined Chemo and Stem Cell drug trial in Nottingham (about an hour away from our home in Solihull near Birmingham in the UK) which is going to see him hospitalised again, potentially for up to 2 months.

Before the drug trial came about, he'd looked into building a small garden recording studio and at the end of last month we had a garden room installed by a local company with a view to converting it. However, with the trial coming up and his health taking a turn for the worse I wondered if I might be able to get his plans into action and try to build (or at least start to build!) the studio while he's away so that the worry is taken off his shoulders and he has a nice surprise when he gets home. I've got a builder/carpenter and an electrician onboard (both great guys who are happy to do "out of hours" work between their regular jobs and who we know and that we've used before) and I have Leigh's plans but I was hoping I could post them up here to check we're on the right path and to ask a few questions about the materials and where best to source them if that's ok?

It's not the biggest studio space compared to those I've seen on here, just 20' x 12' (external measurement) but it's solidly built with the thickest width of timbre the company could supply (44mm). We're lucky in that although we have neighbours, they're only on 2 side of our garden, and their houses are approximately 40ft away from the studio. As far as budget goes, we have £2500 (possibly £3000) available, which again I'm sure is not a lot compared to some but hopefully enough to at least get us a fair way. He's into playing and recording Alt-Electro-Rock music and I know he was looking at using the space primarily for recording rather than as a live room or rehearsal space for the band as well (although if the sound-proofing could make the latter possible I know he'd like to!).

Here are some photos of the studio space as it stands now and Leigh's diagrams (I've had to reduce them to fit on the page and on 2 of them this means the text is difficult to view. Because of this I've included links to the originals as well)

















Originals:

http://i1240.photobucket.com/albums/gg4 ... Plan01.jpg

http://i1240.photobucket.com/albums/gg4 ... erials.jpg

http://i1240.photobucket.com/albums/gg4 ... udWall.jpg

http://i1240.photobucket.com/albums/gg4 ... iagram.jpg


I'm trying my best to get up to speed on the processes involved and the reasons behind the designs i.e. the "room within a room" concept; decoupling the walls and floor; the more "mass" the better from a sound-proofing perspective; but, if the designs are sound, there are a few things that are a bit unclear in Leigh's notes that it would be great to get confirmation about:

1. Is 3" x 2" wood ok for the stud walls?

2. If we use 3" x 2" wood that means we'd be looking at 75mm thick Rockwool Slabs. Is that thick enough?

3. There seem to be several different sizes and densities of Rockwool Slab, which one should we go for and what supplier would people in the UK recommend (as I know we'll be needing quite a lot of both the wood and the Rockwool Slabs, I'm worried in case I order the wrong thing!)?

4. What width should the air gap be between the stud wall and the shed wall (ideally we need the smallest size possible as space is a bit of an issue)?

5. Aside from the 3 layers of plasterboard fixed onto the inside of the stud wall, should we put another layer of plasterboard on the side of the stud wall that faces the air gap? If so, how should this be fixed (with resilient bars again?) and should "acoustic membrane" be used as well (I'm not entirely sure what acoustic membrane is at this stage or how it's applied but I'm about to look it up! )

6. In the Cut Away design, the plasterboard rests on an "Isolating Strip". What size and make should we get and where would be the best place to buy it from?

7. There also seems to be a sizable gap between the plasterboard and the flooring; Leigh mentions using some sort of liquid sealant to fill it; is this right and if so, what should we use?

8. Vinyl matting is mentioned as needing to be used in making up the flooring (above and below the wooden frame stuffed with Rockwool). If this is right, what should we go for?

9. As the Top Down diagram shows, Leigh was thinking about partitioning off the Drum/Vocal section from the main area (I know he wanted to create one big booth that could be used for either purpose, as well as for mic'ing up guitar amps. However I do know that at one stage he was considering putting in a further partition to separate the Drum section from the Vocal section as well...this isn't on the diagram though and I don't know if you'd recommend it? To be honest, I'm not sure we'd have the space to do it!). How should we connect this main partition to the main stud wall? Should it be isolated from the main stud wall somehow?

10. I know Leigh wanted to keep the apex roof if possible. Will it be ok making up more wood frames filled with Rockwool and fixing them onto and between the main roof supports?

11. Leigh was worried about the double doors being a big problem. In the top down plan he mentions a possible workaround of putting a section of stud wall/rockwool/plasterboard on rails so it can be moved in front of the doors then held in place with "compression latches" and a rubber door seal. Would this be viable or is there a better alternative that wouldn't cut the space down too much? With no other windows in the building I know having the option to sometimes have at least a little natural light was important to him as he'd be spending a good deal of his time in there.

I know I'm probably biting off far more than I can chew but if we're on the right track it would be great to know and to get any advice we can on the build before I start ordering materials (which ideally would be good to start doing this week if possible). I'll be passing on all info to our builder and electrician so, fingers crossed, between us we'll be able to figure it all out.

Many thanks,

Lucie.

Hi Lucie, an Welcome to the forum!

Very nice first post, by the way. All of the details that we need to help you are in there. But there's one thing that you are missing: Please fill in your location in your profile.

I want to answer your post in detail, but there's a lot to say and it's 2:00 AM here, so I need to get some sleep first! I'll get back to you tomorrow. Suffice it to say that you are on the right track mostly, and this should work out well. There's some things that you are planning but really don't need to do, and others that can be improved, and still others that you haven't thought of yet, but overall the general idea is good. For example, you don't need the resilient bar because your wall, as described, is already decoupled. You don't need to decouple it twice. You also most likely do not need the floating floor, since the shed is built on a concrete slab, and that's plenty good enough for what you need. So you can save yourself lots of money, (and time) by not doing those.

But I'll get back to you tomorrow in more detail, and I'll answer all of your questions too.

ZZZZZzzzzzzzz......


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Hi again, Lucie. OK, I have a bit more time now, so here goes:

Sure it's OK! That's what the forum is all about!

That's pretty thick, and should make a decent outer-leaf for the isolation. I don't know how much research you've done so far, but the basic plan for heavy isolating (which is what you need for drums) is to build a "room inside a room", which means pretty much what it says: There need to be two sets of surfaces around the studio (called "leaves" in technical parlance), with a gap between them. So your existing solid wood building will be your "outer leaf", then you only need to build the "inner leaf" to complete the isolation shell. The inner leaf is normally built with stud framing and drywall on only one side of the framing, and some form of fibrous insulation in the gap between the two.

The AMOUNT of isolation you will get depends basically on two things: how much mass you have in each leaf, and how big the gap is between them. In other words, heavy, thick, dense materials are better at isolating than thin light-weight materials, and a big gap is better than a small gap.

Leigh's plans already show this type of construction, so clearly he did some good research on this already. But there are also some things on his plans that are not needed, so I'll go over those for you, and try to explain why, and there are also some misconceptions in his notes.

Firstly, take a look at the sixth image you posted, showing the detail of the wall and floor construction. There are several errors here. Firstly, you do not need the resilient bar. The purpose of resilient bar is to decouple the drywall (I think you call it "plasterboard" in the UK) from the studs for people who are NOT building a second stud frame. For example, if you had a wall with drywall on both sides, you could take off the drywall from one side, but resilient bars across the studs, and put the drywall back on again: The drywall is now "decoupled" from the studs, meaning that any vibration in the drywall will be absorbed by the resilient bar, and will not get through to the drywall on the other side. In your case, you are already decoupling the entire wall by building a separate frame, so you don't need to decouple it again with resilient bar. decoupling twice is unnecessary, gains you nothing, and wastes both money and space (not to mention time). So you can leave that out, and save yourself some money there.

Next, there's a not on that same diagram that says "Fix layer 1 to the resilient bar. Fix layers 2 and 3 with Green Glue". There's a major misunderstanding there: You cannot fix drywall with Green Glue, because it isn't really glue at all! That's just a nifty trade name for the product, but it is NOT meant to be adhesive, and cannot be used to stick layers of drywall together. That would be dangerous: sooner or later the drywall would come "unstuck" and fall off, possibly injuring someone.

Green Glue is an acoustic damping product that goes between the layers of drywall to increase isolation. Technically, it is a visco-elastic polymer, which means that it never dries hard and stays soft and rubbery forever. It works as "constrained layer damping", which is a fancy term that means it helps to improve isolation for some types of sound. So yes, it is useful and you can use it, but no, do NOT true to use it as glue! That's not what it is for (despite the name). So you still need to attach each layer as it goes up, with nails, directly into the studs (no resilient channel). You'll need progressively longer nails for each additional layer, as the nails need to penetrate deeply into the studs, so take that into account. The first layer can use normal drywall nails, but they need to be 15mm longer for the second layer, and another 15mm longer than that for the third layer.

Next, same diagram: There's a note there saying that Leigh planned to use different thicknesses of drywall, a "sandwich" of 19mm, 15mm and 12mm layers. That's a myth. Some places on the internet talk about how you can use different thicknesses and different materials to improve internal refraction inside the wall, and change the angles, speeds and other things of the sound waves as they go through the wall, thus increasing isolation. While there is some truth to this, the simple fact remains that "mass rules". Mass is more important. The effect you get from these sandwiches of materials is not very large, and it's better to simply make all three layers as thick as possible, thus increasing the total mass, and really improving the isolation. And if you are already using Green Glue in there, then you already have this effect from the Green Glue itself, so there would be very little additional benefit (if any) from making the middle layer of drywall thinner. Don't do that: just use three layers of 15mm drywall, or if you have the budget (and plenty of strong workers!) then go with 3 layers of 19mm. But that's probably overkill for what you need anyway. Three layers of 15mm is already more than you need, plenty massive, and will give you serious isolation, if done right.

Leigh also asks some questions on that same diagram: One is about the density of the mineral wool insulation that goes in the wall cavity. The answer is: roughly 50 kg/m3. Do not use mineral wool that is very much denser or very much lighter than this. This is the optimal density for best isolation. So try to find something that has density close to this, and you'll be fine. However, if you decide to switch to fiberglass insulation instead, then the optimal density for that is about 30 kg/m3. Each type of insulation has its own characteristics, so be careful with substituting.

Another question is about the depth of the gap between the inner and outer leaf: At least 10 cm, never less, and more if you can afford to lose the space in the room. HOWEVER! There's another misconception evident on that diagram: the term "air gap" refers to the total distance between the existing timber wall and the first layer of plasterboard (drywall) that you put on the studs. In other words, it includes the insulation! When you think about it, insulation is mostly air anyway, so putting insulation in the cavity does not take out air gap: the air gap is the entire depth of the cavity, regardless of whether or not it is filled with insulation.

So, assuming that you will use 40x90 mm studs (also called "2x4's" generally), to get that 10cm air gap, then you'd only need to leave a space of about 10mm between the studs and the existing wall, since the studs themselves provide 90mm of depth. You can leave MORE space if you want, and that will certainly help with isolation, but to get the minimum 10cm gap, you only need a 1 cm distance between the timber wall and the stud frame.

It looks like Leigh was expecting to leave a larger gap, perhaps aiming for greater isolation, so you can leave whatever size gap you feel will still leave you with a decent amount of space in the finished room. Maybe a total air gap depth of 15cm would be good, which means that you'd need to leave 6cm between the wall and the stud frame.

Leigh also asks about how much mineral wool he needs to put in the cavity: He mentions 75mm, and that's OK, but here it's a case of "more is better". If your budget permits, then you could fill almost the entire cavity with mineral wool, and once again that will improve the total isolation.

Still on the same diagram, there's a light blue rectangle under the layers or drywall, marked "Isolating strip: size? make?". The normal way of doing that is simply with the same type of acoustic sealant that you'll be using by the truckload anyway: As your workers put up each layer of drywall, tell them to place a thin shim on the floor to support the drywall while they nail it, then once it is nailed take out the shim and fill the gap with a piece of backer rod and a bead of acoustic sealant. Repeat the same procedure for each layer of drywall, so you will have a total of size seals under there: one piece of backer rod and one bead of sealant for each sheet of drywall.

(If you can't get good acoustic sealant, then you can substitute a good quality bathroom caulk, but get one that stays flexible and rubbery, and never goes hard!)

(If you can't get backer rod, then don't worry about it too much: just use the sealant or caulk.)

On the same diagram, the floor design is a totally different issue that needs addressing, since what he has there is not a good plan, but I'm running out of time again tonight, so I'll go into that in another post tomorrow.

OK, on to your specific questions:

Probably not. I'd go with 2x4's, which are probably 40x90 in the UK, I think. The reason here is that this is a HUGE amount of mass that you'll be putting on those studs. Each square meter of your walls will weigh about 40 kilograms, so the studs need to be pretty sturdy to take that heavy load. You also need to get a structural engineer in to check the floor system of that shed, and make sure that it can take the load! We are talking about putting a load of thousands of kilograms in there, so this is important. Only a qualified engineer can tell you if the building you have can take the load.

Actually, that isn't correct! Wood doesn't really measure what it says it does. This is confusing, but 2x4 studs are not really 2 inches by 4 inches at all! In reality they are only 1-1/2" x 3-1/2". So you can't get 75mm of rockwool into a stud space built with 2x3's, since the actual depth is not 3 inches: it is only 2-1/2", which is just 63.5mm! This is very confusing, but it's related to the way wood contracts when it dries. They really do cut them as 2" by 4" at the sawmill, but as the wood dries, it loses a lot of water, and shrinks down to a smaller size.

But anyway, I'd go with 2x4's for the wall studs, and at least that for the ceiling joists, maybe even larger.

Not sure about suppliers in the UK, but density of around 50kg/m3 is what you need, give or take a bit. Rockwool is a trade name for a specific brand. The generic term is "mineral wool".

Also covered above: the air gap should be 4 inches or 10 cm minimum. The term refers to the distance across the complete cavity, from surface to surface, including the insulation fill (Rockwool), and NOT just the unfilled part. So if you use three layers of 15mm drywall on 2x4 studs, then the total amount of space taken up by that wall will be: 90mm for the studs, 10mm for the extra gap (to get a total of 100mm), and 45mm for the drywall (3 x 15) = 145mm, or roughly 6 inches. There will be at least 75mm of Rockwool in that cavity, and hopefully all 100mm will be filled. Just make sure that you do not over-fill the cavity: Don't force it in! Put in just enough to fill it comfortably, without pushing and shoving or compressing it to make it fit.

Not necessary, no, but you can if you want. With 44 mm timber, you already have good mass there. Just make very, very certain that the timber is very well sealed! There can be no gaps at all in that wall. If it looks like there are gaps there, then seal all of them by forcing abundant acoustic sealant deep into the gap. If there are a LOT of gaps, then yes, add the extra layer of drywall, if you can afford it. You could also use OSB or plywood, instead of drywall. And no matter what you use, seal it! Sealing is incredibly important.

definitely not! You should NEVER leave a small air gap, such as you'd get from using resilient bar directly over a wall surface. That would create a really lousy isolation system. Just put the drywall directly up against the timber, use Green Glue in between if you can afford to, and screws it in place exactly as though you were attaching it to studs.

Another myth! Technically, that's called Mass Loaded Vinyl ("MLV"), and is a thick rubbery layer that is very heavy. Yes, it does work to help isolate sound, but it is extremely expensive! Sounds waves don't care how much you pay for your mass; they can't read price tags, and all they do is react to the amount of mass in the wall. So get the cheapest mass that will do the job! There's nothing magical about MLV: It's just mass in a different form. Yes, it is limp mass, and does have some limited uses in acoustics, but it makes no sense to sandwich inside a wall: that's just a huge waste of money. Forget MLV: you don't need it. Just use relatively cheap mass, such as drywall, plywood, OSB and MDF. kg for kg, they are much cheaper than MLV.

Answered above: build that up as you go, with backer rod and acoustic sealant under each layer of drywall. And not just under it! Also above it, where it joins the new ceiling, and where it meets the other new walls.

No, I would not do the floor like that at all. Big waste of money, not good isolation, waste of room height (which you don't have much of!). But no time to go into that tonight: that's a whole book full, all on its own!

same answer as above: That's not the right way to do the floor.

To be very honest, I don't think you have enough space in there to do that. It would be better to just set up the drums in the rear of the one single room, and use gobos to get some limited separation of instruments. There simply isn't enough space for that. I mean, you COULD fit the walls in there, but you'd end up with to very tiny, very lousy sounding rooms, instead of one spacious, decent sounding room. sound needs space, volume, area to sound good. ITU and EBU recommendations are for a minimum room volume of 43 cubic meters. Any less than that, and the acoustic properties start falling off, fast. You can just barely make that with one room in your shed, and in fact you probably won't even reach that, by the time you have all the isolation in place. But if you tried to have two rooms, you'd have less than half of that in each. Waaaaay less.

Not really. The "room in a room" concept applies to the ceiling as well! In other words, you need to build a new ceiling in the exact same manner as the new walls. That new ceiling must rest ONLY on the new walls, and CANNOT touch any part of the existing structure. It has to be totally separate. That's why the concept is called "room in a room". Rooms have walls and ceilings too! Isolation is an "all or nothing" proposition. All four walls, and the ceiling, have to be done to the same level. Same procedure for the ceiling: 2x4 framing (gabled if you want), with three layers of drywall, sealed and caulked.

They are! And a big problem, too. But as I said, I'm out of time again tonight (and wearing out my keyboard, too!), so I'll cover that another day, along with your floor. But basically our best option here if you want natural light is two sets of sliding glass doors, of the right type, and with thick laminate glass in them. The only trouble with those things is price: They are NOT cheap! They'll do what you want, but you'll blow your entire budget just on those...

Starting this week seems more than just a little optimistic!!!!! You don't even have a workable plan yet: maybe you should re-think that schedule slightly....

I'm sure we can figure it out, but there's more to this than Leigh had in his notes, and some major parts are missing. Namely: HVAC. That stands for Heating, Ventilation and Air Conditioning. In order to be fully isolated, the room will be built as two totally sealed air-tight shells. That's the "room in a room" thing again. each "room" is sealed, hermetically. Even the doors will have multiple rubber seals on them. So you MUST have a system for getting fresh air into the room, and getting stale air out of it. That's the "V" part of HVAC. But moving air in and out means that you have to cut holes in your perfect air-tight seals! So clearly there's an issue here: you need isolated ducts, in-line silencers, and very quite fans to move the air through the ducts. It can be done fairly simply, but it's something that isn't even on your list, and is critically important: Leigh won't be able to work in there for very long at all with no air to breathe!

The room will also be surrounded by a very thick layer of thermal insulation, both in the wall cavity and also in the room treatment: so heat ain't goin' nowhere! What's in stays in, and what’s outside stays outside. So you also need a way to cool that place, especially in summer. That's the "AC" part of HVAC. The air conditioner also does something else that is very important: it controls humidity. Hugely important, in fact. Musical instruments, microphones, equipment, and people are all sensitive to humidity. It has to be kept under control. And finally, if you live in a very cold climate, you might even need the "H" part of HVAC: heating. That can probably be handled by the same air conditioning unit: some do both.

You also need to consider how to isolate the electrical system: Your electrician can't simply go around punching holes in your triple-super-sealed-hermetic-acoustic-isolation-walls that cost you a fortune to build, to put in plugs, lights and switches! There can be NO holes! Everything must be surface mounted within the room. No penetrations at all through the wall. That's another key challenge.

So, anyway, the good news is that you are totally on the right basic track with what Leigh has on the diagrams, but with some caveats. Some are small, but some are big. But the other good news is that they can all be fixed.

Hopefully tomorrow I'll be able to add some more, but this should help a bit in the meantime.


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Stuart, I can't thank you enough for taking the time to put together such a helpful post. It really does mean a lot, particularly as this is such a new subject for me and now for the first time since deciding to try and take this on I actually feel as if I know where I'm going!

So, to sum up, (this is more for my benefit than anything, as writing it out helps me nail the information down so to speak!)

1. The resilient bars aren't needed as the outer leaf (new terminology! ) is already decoupled. That in itself makes things a lot easier!

2. Use "Green Glue" but only for it's acoustic properties and not as an adhesive. The plasterboard (dry wall! ) needs to be nailed to the studs with successively longer nails for each layer.

3. Don't use differing thicknesses of drywall. Instead use 15mm (or possibly 19mm) thick drywall in 3 layers.

4. The density of the mineral wool should be approximately 50kg/m3.

5. The air gap includes the depth of the stud wall - it's measured from the outer wall to the first layer of drywall. So if using 2" x 4"s (40mm x 90mm) for the studs, to get the required 100mm (minimum) air gap we only need to leave a 10mm space between the studs and the outer wall.

6. Instead of using "isolation strips" ask the builders to place a thin "shim" on the floor to support the drywall as they nail it to the studs. Remove the shim when the board is fixed and fill the gap with a piece of "backer rod" (just had to Google what that is! ) and a bead of acoustic sealant. If backer rods aren't available then just use sealant. If acoustic sealant isn't available then use a good quality bathroom caulk, one that stays flexible and doesn't go hard with time. Use this method everywhere, not only where the drywall meets the floor but where it joins the ceiling and where it joins the new walls.

7. 2" x 4" actually equates to 1 1/2" x 3 1/2" in reality due to shrinkage. The actual depth will be approximately 89mm so mineral wool needs to be bought with this in mind.

8. All gaps in the timbre outer wall must be sealed with acoustic sealant. If there are lots of gaps then use another layer of plasterboard or OSB (again back to Google to find out it stood for Oriented Strand Board! ) or plywood.

9. Don't use vinyl matting (MLV) as it's expensive and other materials will do the same job for less money.

10. Don't partition off the room as due to the small size it will have a negative effect on the sound quality.

11. The ceiling of the iiner room can be gabled but it must be treated like the walls i.e. 2 x 4 framing filled with mineral wool with 3 layers of drywall all sealed and not touching the outer leaf.

12. A possible solution to the problem of the doors whilst trying to maintain a degree of natural light would be to fit 2 sets of sliding glass doors with thick laminate glass inside them.

13. All electrics must be surface mounted and care must be taken as to how cables and wiring are situated so as not to compromise the sealed inner shell.

14. HVAC!

From reading through your answers, I think the things that stand out in my mind now are the following:

1. The flooring! It sounds like this is an area that needs a major rethink so it would be great to get your help with this if that's still ok?

2. From looking at Leigh's designs I was originally thinking we'd just be filling the wooden stud frame with slabs of mineral wool but after reading this:
am I reading it right by thinking we can even fill the 10mm deep air gap space as well?

3. It sounds like the electrical side of things is going to be tricky. I know the electrician was going to mount everything onto the inner wall as he himself was concerned about compromising the sealed inner walls and had planned to put all wires and cabling inside dado rails. Are there particular ways to mount things like the fusebox, wall sockets and indeed the lighting without harming the acoustic side of things? I haven't given much thought to the lighting at this stage to be honest and that's one of the things that Leigh doesn't seem to mention in his notes but the electrician suggested a mix of 3 fluorescent tubes (a new thin type apparently!) and some seperate spotlights that can be dimmed so he can have the choice between full on lighting or less harsh mood lighting depending on how he feels. I guess the main factor is not so much what the lights are but how they're mounted! How would you recommend we connect it all to the main feed (which he's going to be running from the main box inside the house)? By that I mean, how can we best bring the main cable into the inner room without it harming the room's acoustic properties (maybe up through the corner of the floor somehow and then putting sealant around the cable?)?

4. I completely see your point about the importance of good ventilation, air-con and heating (although our summers here in the middle of England seem to be fleeting at best, air-con would still need to be factored in, just in case ). Leigh hasn't made any notes about it so, like the electrics, as this could easily compromise the effectiveness of the inner room, I'd really appreciate any help you could give me about what type of unit to go for and how best to fit it. It gets terribly cold here in winter time and I know Leigh won't mind me saying that he feels it quite badly particularly when he's going through a bad flare-up of Crohns, so heating in the studio would be an incredibly important factor. If the air-con/extraction unit could handle that side of things as well then that would be great, although I feel it might be best to err on the side of caution and come up with some other additional heating options just in case.

I think my next jobs are to ask the builder about places to source the 2 x 4 wood for the struts (I'll ask him to estimate how much we'll need) and the 15mm plasterboard (I've noticed that some more sound-proof orientated sites offer "acoustic plasterboard" which I need to investigate), look into what type of 50kg/m3 Rockwool slab will best fit, and what kind of acoustic sealant to buy.

Honestly Stuart, thank you so, so much for your help!

Lucie x

Hi again Lucie, and sorry for the long delay in getting back to you! I guess I didn't notice your reply...

Anyway, your 14 point summary pretty much covers it, and everything seems fine on there.

So, on to your other points.

1) Floor. Yup. Problem. Not quite sure what the best solution is there, but it would help to get a better idea of how that existing floor is built, in more detail. Do you have the plans for that? Maybe the company that built it can give you a detailed sketch of how it is built, show the materials in each layer? Or maybe you could take some photos and post them here, especially if there's a gap somewhere so we can see what is UNDER the floor. The things that concern me are: whether or not there is an air gap under it, how it is supported (structurally), how thick it is, and what the structural limitations are for it. You are going to be piling on a huge amount of mass, so it's important to make sure that the floor / foundations can handle that. There are a couple of ways that the floor could be done, but they all add mass. You might need to get a structural engineer to take a look at what you have, and tell you how much extra mass you can add safely.

Yup! If your local building code allows it, then filling the cavity completely is a good idea, as it increases the amount of isolation. So however deep the cavity ends up, you'll get maximum isolation by filling it with insulation. But don't stuff it in tight! Just lay it in until the cavity is just full. If you force it in, then you run the risk of creating a "bridge" across the gap, technically called a "flanking path", and you don't want that.

3) Electrical. There are some structured systems for doing surface mount. Legrand is one that comes to mind, but there are others. But they aren't cheap.

This is the idea:
http://www.legrand.us/wire-cable-manage ... 3inOoHnuSs

But show it to your electrician, and get him to look around: there might be cheaper/better alternatives where you live.

The big issue is wall penetration: You do not want to make holes in the walls! You'll spend a lot of time and money to build them massive and air-tight, so any hole you make destroys that. Even a tiny hole can severely damage your isolation. If air can get through, then so can sound. Obviously, at some point you have to bring the power supply cable into the room, so there has to be one penetration, but that must be done correctly, so that the hole is sealed and the isolation integrity is not lost. So apart from that, you mount everything inside the room, on the walls. Of course, you'll still have to screw things like sockets and light fittings through the drywall and into the studs, but that's OK since the screw will remain in place, filling the hole and sealing it. But you can't have cables going in and out of the wall in the normal manner.

Exactly. Mount them as needed using screws, but make sure that the screws go into the studs and are well seated. Electricians seem to have this habit of misjudging where the studs are, and putting screws through the drywall into thin air on the other side. Then when they realize they didn't hit the stud, they take out the screws and try again, a few mm further over. So you end up with holes poled in your wall! Not good. Tell them to make SURE that ALL screws hit the stud the first time. Some of that ducting doesn't need screws: the thinner ones have self adhesive backing on them, but the bigger ones do need to be screwed.

Wherever is convenient, bring the cable through using conduit, which is basically just PVC piping for electrical cables. So you have conduit going bringing the cable in. Fill the ends of the conduit where the cable goes int and comes out, by stuffing some insulation into the end, around the cable, then seal it with a dab of caulk or acoustic sealant. A section of the conduit also needs to be cut out between the two leaves, and that gap is then wrapped with soft rubber, to decouple, like this:



4) On HVAC: Probably the best type of air conditioner for your project is something called a "split system" or "mini-split system", which, as the name implies, consists of two parts. It's like thye took your typical window-mounted unit, and "split" it in two, putting the noisy part in a box that goes outside, and the quiet part in a box that goes in your room, and you link the two with a couple of copper pipes and an electrical cable. Basically there's a fan and radiator thing in each box, and a compressor / pump in the outside box (that's the noisy part) that circulates the coolant between the two boxes. The better systems do both heating and cooling, by basically reversing the flow of the coolant through the system, so it will cool in summer and heat in winter. Normally, they are better at heating than cooling. There are general rules of thumb for getting the right size unit for your room, but you should take to an HVAC expert about that. Do NOT get a unit that is too big or two small! It MUST be sized correctly. If you get one that is too small (maybe trying to save money), then it will not cycle on and off like it is supposed to, and will run full-time, using a lot of power, making a lot of noise, and never properly heating or cooling the room. If you get one that is too big, thinking that it might cool or heat faster, then it won't cycle enough. You might think that's good, but it isn't, since part of the job that the unit is doing while it cools, is dehumidifying the air. In summer, in enclosed spaces, that's very important. If the unit is too big, it will do very short cooling cycles that get the air cool fast, but because the unit wasn't running for long enough, it won't dehumidify correctly. The air will be too humid, and it will be unpleasant. Not only that, but equipment and musical instruments need constant, controlled humidity to work and sound their best. The sound of some instruments and microphones changes, depending on the humidity, so it needs to be kept under control.

Apart form the actual heating/cooling unit, you'll also need to bring in fresh air and exhaust stale air. That is normally done using quiet fans and ducts. But once again, you a duct that takes in or out, is basically a huge gaping hole in your wall! A major disaster for isolation! So you run the ducts through a box called a "silencer" to deal with that issue. There are several designs and examples on the forum of how to do that.

Watch your budget carefully, and do check the specs even more carefully! Yes, there are some types of drywall that claim to offer higher isolation, but they are much more expensive than ordinary fire-rated drywall, and the simple fact remains that sound waves can't read invoices, and don't care how much you paid for your mass! Sound waves only react to the mass that they encounter, period. If you paid US$ 10 per kilogram or US$ 100 per kilogram just doesn't matter to the sound waves! They really don't give a damn. All they see is a certain amount of mass, density, and rigidity, and they will react in exactly the same way to the same conditions, regardless of price. So it makes sense to get the cheapest mass that will do the job (lowest cost per kilogram), and in most places in the world, that turns out to be pain old, ordinary, common gypsum plasterboard, also called "drywall" and "sheetrock" and a few other things. So unless you do the math and find something denser, heavier or more rigid, for a lower price, then just stick with what is known to work. There are no magical materials (despite what some manufacturers claim in their advertising!) Sound waves obey the laws of physics, not the laws of marketing, and the same applies to materials. Caveat Emptor!

You're welcome! That's what we are here for: to help.


- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Hi Stuart. It's no problem, I just appreciate the help! I lept logging back in for a few weeks after my last post but then Leigh took a turn for the worse and I haven't really had chance to sort things out and reply properly till now. After going into surgery unexpectedly and thankfully coming out ok (scheduled again for this coming Wednesday but luckily a much smaller Op) it's changed our plans somewhat so Leigh now knows what I've been trying to sort out and I must pass on his thanks for the help as well Although in better shape than he was he's still not really up to doing much so I'm still going ahead project managing the build but thankfully now with both his and your help!

Over the past few weeks, the electrician has come and installed a feed from the main box, siting both it and the fuse box externally so that it has as little impact on the sound proofing as possible (I'll post some photos this weekend). Thank you so much for the diagram, I'll pass it and the "Raceway" info along to him

As far as the floor goes, again, I'll post some photos and try to get together some info from the suppliers themselves. Off the top of my head the floor boards are the same 44mm wood as used elsewhere and the entire structure was built on a thick concrete base, resting on wooden timbers to allow an air gap between the floor boards and the concrete.

As far as everything else goes all the timbre, plasterboard, sealant etc has all been ordered and work starts on the studding of the internal room this Monday so I'll be sure to post up photos as it progresses!

Sorry for the quick post, although it's a bit late over here I wanted to reply! I'll get some photos together and hopefully post again this weekend

Lucie.

Work started today!

Re: the base - here's a photo...



We're still waiting on official confirmation of the specs from the suppliers but it essentially looks like the same 44mm timbre for the flooring raised up off a solid concrete base by a series of 60mmx50mm lengths of wood (which run from end to end). So, if the base is sufficicient, what would you suggest as the best method for dealing with the floor? Ideally it would be great to have a rough idea of where we're going as the builders are here for the next 4 days in a row and we can talk it over with them and hopefully start moving forward with buying the necessary materials

And speaking of materials, we had several deliveries today! Our garage is somewhat stuffed!





(and that's not all of the plasterboard! )

The stud wall started coming together today:



And here's a quick shot of the external electrics (a very professional install and all well shielded):



The HVAC system is still a bit of a question mark at the moment. In our case we're thinking that ideally it would be great to have one where the majority of the system is actually on the outside of the studio. As you can see from the last photo we have quite a bit of dead space at the rear of the building in which it could sit very nicely and still be out of the way, however at this stage I'm not even sure a mostly external system like that exists (will be doing a lot of internet research tonight and a fair bit of ringing round tomorrow I think!).

Studding finished and Rockwool slabs in



Two of the acosutic plasterboard panels went up on the roof section before we finished today but the rest should be up by the end of tomorrow all being well.

Lucie.

Whoa!!! Hang on there, Lucie! I'm seeing some Big Red Flags there in those photos!

First, I hope it's just the camera angle or the lighting, but to me it looks like that framing that you put up is attached to the existing ceiling! Is that what they did? If so, that's a problem... A big problem.

There seems to be a gap between the studs and the outer leaf wall, which is good, but the top plate (the horizontal "stud" going across the tops of all the vertical studs) seems to be firmly attached to the original ceiling: It should NOT be attached. The walls are totally free-standing, and cannot touch ANY part of the existing structure, except the floor. The new ceiling joists will tie the tops of the walls to each other, but once again, the new ceiling CANNOT touch any part of the existing structure. The concept is simple: you are building one room inside another room, and they don't touch each other, at all. Even one single connection is a no-no. Not even a single nail can connect the two. Any connection at all will destroy the isolation ("soundproofing") that you are trying so hard to achieve.

So if the workmen have attached the new walls to the ceiling, then they need to fix that right away, before doing anything else. and you also need to check very, very carefully, to make sure that none of those new studs is touching the existing walls at any point.

They also have not framed around the trusses: those triangular things coming down from the existing ceiling CANNOT be inside the inner leaf: they are part of the outer leaf. So the crew will have to frame the inner-leaf ceiling around those (once again, without touching them), in order to keep them out of the room.


BUT!!!... there's another even bigger issue here: You were supposed to seal the existing, original walls, BEFORE you started on the framing!!! That was point number 8 on your list of 14 Very Important Things, and it looks like they did not do that. If so, that's a huge mistake. If the outer leaf is not sealed, you won't get good isolation. Sealing is incredibly important, acoustically. It is critical.

That existing wall is just bare timber, and there are, without any doubt, numerous tiny air cracks all over the place, even though you can't see them. All of that MUST be sealed before you go on to building the inner leaf. Every single gap and crack must be sealed with acoustic sealant (or a good quality flexible caulk, if you can't get acoustic sealant). It is VERY important that both leaves of your studio are totally sealed, absolutely air-tight, fully hermetic. I can't stress this point enough. If not, then once again that seriously compromises your isolation: all of the time, effort and money you are investing in this is wasted. No seal = no isolation. It's that simple.

Air tight seals and complete decoupling are THEY two key issues here, and so far your workers do not seem to have done either!

I'd really suggest that, before they do anything else, you get them to take out that Rockwool again, seal the outer leaf totally, detach the top plate from the existing ceiling (assuming that it is attached), add the framing for the new ceiling around the trusses, and only THEN put the Rockwool back in place again.

This probably looks like major bad news to you, but it's not that bad. It happens all the time, so don't feel too depressed.

This seems to be a very common problem with construction workers who have never done studios before: they don't understand why all this is so important, since nobody ever told them! They think it is just like building a normal house, so they do the normal things they are used to doing, where decoupling and seals don't matter. Since they don't understand the principles of acoustics, they don't bother doing the things that are critical for isolation. But building a studio is nothing at all like building a house, store, or office. Same materials, same tools, but very different techniques. You are not the first person on the forum to have this issue, not by any means, and I'm sure you won't be the last! It's a rather common problem, and the only solution is to watch your construction crew like a hawk, make sure they do it right, and post plenty of photos here, so we can watch them too and catch issues like this early on.

Fortunately, your build has not gone too far, and undoing what they did wrong is not a big deal right now. Just so you don't feel so bad, there's another thread going on in the forum right now (here: viewtopic.php?f=2&t=17363 ), by a guy in Greece with the exact same problem: his work crew did everything wrong, and he had to take out a huge amount of stuff, then do it right. He's almost finished now, and VERY happy that he spent the time to rip out his entire studio, back to bare walls, and do it again. You are lucky in that your builders didn't get anywhere near as far as his guys had, so there's not too much to undo for you! But take a look at his thread, to see how he suffered...

OK, I guess this is where you start feeling pretty bad, down, bummed out, depressed, and wanting to kick the dog (or yourself, or the workers!), and maybe just give up and throw in the towel, but understandable. It's not your fault that they don't know how to do it! Maybe you need to spend a few minutes with them, first thing tomorrow, and explain the above to them: building a studio is NOT like building a house or an office. It is very different, because there are some very critical factors that they must consider here, that they don't normally need to worry about. Number one is air-tight seals on EVERYTHING. Number two is decoupling EVERYTHING (keeping the two leaves totally separate). Number three is not improvising or substituting AT ALL: there's a reason for every aspect of the plan we laid out for you, and there are acoustic consequences for any changes that they make. Those consequences are probably not clear to them at all, since they don't have to understand the acoustic theory or the equations: they just need to follow the instructions carefully, and if they run into a problem, then ask! If something doesn't make sense, or doesn't seem to work, or doesn't fit, then take a couple of photos of that, post them here, and ask how to fix it, while they carry on doing something else.

I'll try to follow your thread more closely, and check it for updates more often, since it looks like you are going to need some extra eyes to make sure they do it right. Also, PM me, and I'll send you my direct e-mail address, so you can mail me if there's an emergency.

It ain't the end of the world! Just a setback. If you don't have any setbacks on a studio build, then you are doing something wrong!


- Stuart -



(PS: Just saw your comment about the HVAC. The type of system you are looking for is called a "mini-split system": The big noisy part goes outside, and the small quiet part goes inside. They are connected by a couple of copper pipes and an electrical cable. That's your best bet, for sure. Some of them are for cooling only, but what you need is one that does both heating and cooling, as as needed).

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Panic over! We're very lucky in that the builders who are on the job are fantastic guys and they had no problem at all taking the rockwool out, completely sealing the bare wood and then addressing the trusses and making sure every part of the inner room was isolated from the outer. They'd kept everything seperate but had tied the inner leaf in a few places to the outer with metal ties. These were removed and the trusses boxed in completely the upshot being that now there is not one single point where the inner leaf touches the outer. The internal structure is entirely self supporting and very sturdily built, so much so that the head builder Rob, a very big muscly guy, jumped up and hung off the internal structure before the plasterboard went on to demonstrate! We also ordered more Rockwool as aside from needing more for the bass traps, the space in the apex allowed for another few extra layers.

The plasterboard has now gone up (up to the second layer with one layer left to go), but every single hole and gap has been sealed throughout the process...they've used so much sealant it's untrue!

Thanks so much for catching these potential problems though Stuart, it really was a massive help. It was a difficult few days with Leigh going in for surgery again on Wednesday only to have the operation moved to the Thursday (after waiting on the ward prepped and ready to go all day due to a mix up with the surgery list!) but like I said the builders have been great and really understanding. Nothing has been too much trouble for them and they genuinely want to make sure that Leigh has the best studio space they can give him.



The final layer of plasterboard is going up on Monday and hopefully the main door will be going in as well. Should they put a thin skim of plaster over the final boards or is there another approach (acoustic fabric or something similar?). We're still not sure how to put the floor together so any advice on materials and their arrangement would be great Stuart (and thank you so much for offering your email address! I'll PM you mine ).

Lucie.

Hi Lucie. Just want to say that what you are doing is fantastic. Your husband is a very fortunate guy.

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Audio engineers use their equipment to listen to the music.
Audiophiles use your music to listen to their equipment.

To be honest, the Crohn's has taken so much from him over the years. With the amount of pain he puts up with on a daily basis, and the amount of time he spends in hospital or stuck at home not able to leave the house, being able to do something like this which will enable him to carry on doing something he loves is the least that I can do!

The plastering is finished now and the guys are working on the main door today:



However, we're still really unsure about what to do with the flooring. Does anyone have any suggestions on how best to approach it? From the reading we've done so far it's been suggested that laying down squares of neoprene pads (or a subsitute?) at regular intervals all over the floor then covering with plywood is the way forward. It seems people sometimes then add sheets of rubber matting and another layer of plywood. Interestingly, we've seen a lot of threads where people say not to use carpet to finish it, but go for a reflective material: wood if funds allow or linoleum etc if going for the cheaper option e.g. http://www.gearslutz.com/board/studio-building-acoustics/146717-wood-floor-carpet.html Quoting from that page:

Carpet typically absorbs high frequencies and some midrange, but does nothing for bass and lower midrange. Using carpet as an acoustic treatment, in most rooms, results in a room that is dull and boomy. Most of the time you need a thicker absorber such as 4-inch or, better, 6-inch fiberglass, or acoustic tile, and you can't walk around on either of those. Hence the general recommendation that you avoid carpet on the floor and use broadband absorbers elsewhere.

However, the room is small (5m 40cm x 3m now that the soundproofing is in) and the ceiling is low so would a reflective floor be right for this particular build? There will be an acoustic drum kit set-up in one corner and this is another factor that's got us thinking. Will the flooring need to be done differently to cope? Should we add a drum riser? Sorry for all the questions, I just don't want to make an error this far down the track but unfortunately it's getting very close to the time when the builders will need to start working on it (although we will have some breathing space while we paint the walls, and install the wiring and lighting).

Two final things before I stop bothering everyone - firstly, the bass traps. We're still aiming to use Leigh's original plans for these which were in turn were originally taken from these photos:







In these photos it appears as if the corner bass traps are sitting on top of the floor - is this the right way to do it? Also, does the angle of the corner bass traps make a difference? As it stands at the moment we've now run out of Rockwool so we've got to order some more for the corner traps (and for the rectangular bass traps that are mounted on the walls if people think this is also a good idea?) and try to find somewhere that sells the acoustic fabric that's stretched over them (stapled in place on top of the wooden frame as seen in the photos). If there's a better way of approaching these bass traps though it would be great to know everyone's thoughts

And lastly, the HVAC system. After Stuart suggested the mini-split system we looked into it and it really does seem the best option for our particular build. However there seems to be a fairly bewildering number of different units on the market so I was just wondering if anyone had any recommendations? Are some better than others or are they all more or less the same (in regards to how well they perform, efficiency and noise generated)?

Thanks again,

Lucie.

Hey Lucie,
As many have said already we applaud you. What a great partner he has.

As far as your flooring issue goes. It looks like there is a cavity between the wood floor and the slab. Maybe 2"-3"?
If it was mine I would use a flowable grout to fill the cavity. Either gravity feed it with a vibrator or pump it in.
Inexpensive and solid!
Just a thought

Tom

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Thanks Tom
We mentioned using flowable grout to our builder but he hadn't heard of it but he was definitely open to the idea! The only reservation he had was that as it stands, the air gap is there to prevent the wood from rotting over time. If we pump in flowable grout will it mean that we have problems further down the line with the wooden floor deteriorating or would there be a way to circumvent this?

Almost forgot to say where we're up to now! The door's now on bar the acoustic seal that's going around the internal edge. The plaster finally dried and the first coat of paint went on today (I'll take some photos tomorrow ). We've got a bit of a delay now as the electrician can't come till Saturday now and we've got to source this mini-split HVAC system but once we know where we're going with the floor we can at least get on with that. I found the following on this site http://m.humbuckermusic.com/jul5th20buil.html?more=true the other day:

One example of a partial solution to this problem was a home studio owner who used the carpet left by the previous owner of the house, together with some salvaged carpet underlay, to provide the resilient layer of a basic floating floor. There wasn't any need to put the underlay actually under the carpet since no-one was going to see either ever again. On top of the underlay were laid squares of 18mm chipboard, two layers thick, with the joins staggered so that there was no gap for sound to penetrate. Any acoustic designer will tell you that when you go to the trouble of decoupling structures in this way, using a resilient layer, then the worst thing you can do is to 'bridge' the structures. This would have happened if the chipboard was screwed down to the floorboards, so only the two layers were screwed together. Bridging would also have occured if the chipboard butted directly up against the walls, so a gap of about 10mm was left. All the gaps, between the chipboard squares and between the chipboard and the walls were filled with mastic. Mastic can be a rubbery or bituminous compound easily obtained from do-it-yourself merchants which is used to fill in small gaps, or in some cases it can act as a resilient support in its own right. The rubbery mastic that you can apply with a mastic gun is good for most purposes, the bituminous type is best kept for more heavy-duty building projects. On top of the chipboard was placed some more carpet underlay, and finally a carpet.

We were thinking the final layer should be a laminate flooring rather than carpet but does this method sound the right route to go down? We did find an alternative to using underlay/carpet as the resilient layer though I'm guessing it's going to be a fair bit more expensive: http://www.soundservice.co.uk/R10_index.htm