John Sayers' Recording Studio Design Forum Archive

Hello all,

I have been planning for quite some time now, and have basically started to have second thoughts about the layout.

My room will be in a garage. The garage construction is as follows

Overall outside dimensions:
Footprint: 36'8" - the front of garage with a man door at one end and overhead at other
26'4" - from front to back with a 31" window in each side
2x4 walls on concrete block foundation
4" poured concrete slab on compacted stone (not positive about the 4" depth but pretty sure)
The walls sit on a 2x6 sill plate one the top course of the concrete blocks 1 block proud of the slab
Exterior sheathing is homasote with tyvek and vinyl siding (with CDX plywood at the corners (4x8 sheets horizontal)
Roof - truss system (2x4 scissor truss) ridge vent in roof

Currently I have removed any Sheetrock from the inside and I am in the process of doubling up the exterior. I am doing so per detailed directions in Rod Gervais' book.
So I have sealed the exterior with silicon (from inside). In process of applying Sheetrock to the inside of the homosate and using backer rod and the sealing with silicon.

My intentions are to finishing the installation of the Sheetrock to the outer shell and seal. Insulate with pink fluffy. Frame new inner shell walls so a 4" air gap is created. Insulate that leaf, install 2 layers of 5/8" rock with Green Glue between.
Ceiling will be hung from hat channel attached to RSIC 1 clips fastened to the bottom cord of trusses per manufacturer recommended spacing. Then 2 layers of 5/8" rock with green glue between. I have specd the load requirements of the trusses and I'm fine.

I will be carrying the ceiling over the interior wall using backer rod and caulk so as not to create flanking situation (per Mr. Gervais book) as well as doing a similar firestop construction every 10 feet inside the walls. Basically I will rip down some CDX attach to studs of inner shell have them attach to outer shell ( not actually attach I just didn't have the right wording) by the use of backer rod and caulk, so they are still decoupled.

I have 2 locations where I have a fire rated conduit with the wax insert to mold around wires, cables etc. that will entered the shell at 2 locations and be sealed appropriately. I then intended to ruin wiring along inside of the inner shell. Explanation: I intend to create a step or box if you will that runs around perimeter of entire room. This will be used as a chase for any wires, the top will likely be where I mount receptacles, I will include absorption inside and route channels the length of them. Also I had considered making the face of these convex by using Luann and bending it sort of like a poly diffuser. I thought this would eliminate a corner around entire room, as well as giving me a chase for wires (and future access in the event of maintenance), as well as a solid surface to mount receptacles that is not recessed from plane of the acoustic frame.

I will try to snap a pic of my drawings to upload. I'm sorry I tried to learn schetcup but just didn't have the time so I did it like I do most drawings, with graph paper and drafting tools. They are to scale, though that probably won't matter once I take a picture.

I'm sure I am leaving a bunch out, but if someone is willing to offer their advice I will do whatever it takes to provide more information.

My intended use is as a rehearsal space and as a recording and mixing room. I know that is nearly impossible to do. But if I have to sacrifice the critical listening aspect to have a room that produces the best sound I am ok with that.

I am mostly a musician, very new to sound. But I have quite a bit of quality equipment. I will be happy to provide more info as needed regarding that.

Oh yes - I wanted to created an acoustic frame next. Not another leaf but a frame still that things are somewhat flush and I don't have protrusions everywhere there is treatment. So in doing this I also would like to basically create areas that can be altered from absorptive to diffuse. I have some plans to hinge some treatments, to put some on sliding tracks, and also to create a box of sorts that can be inserted into the space in the wall one way as an absorber, turned around and it is either a diffuser or perhaps maybe broadband one way and tuned another, but also be able to take the box and use it as a gobo throughout the room.

Sounds crazy I'm sure but really by building this acoustic frame that esseontially allows for 2x4 sections to interface, I can exist in the room and run measurements then apply panels where necessary or not.

My main issue is that I am gun shy. I don't want to make a million mistakes.
There is much more to this but this post is extremely long, so if anyone has any interest in providing some advice, like I said, I will be happy to make any information I can available.

Electric : star system outlined by ROd Gervais - my brother in law is electrician and he is going to take care of that.
I have a mini split that I just purchased.
I have most of the 2x material, most of the Sheetrock, the green glue, a pallet of pink fluffy, guildford of maines fabric (4 rolls of the top quality Fire rated one)
RSIC clips, hat channel,
And more
Basically 90% of the material.
Ok thank you in advance for any advice.

I have to take a new pic bc I have marked the photo I have up so i am going to post this so I don't lose everything I typed. I will post pics in the post following this.

Thanks

Aaron

Hi there, Aaron, and Welcome!

Footprint: 36'8" - the front of garage with a man door at one end and overhead at other
26'4" - from front to back

Wow! That's a very large room! Nearly a thousand square feet!

Exterior sheathing is homasote

Homasote? Are you sure about that? It would be rather unusual to use such a soft, light-weight, flaky material for the exterior of a building, even if it is just a garage. Homasote isn't weatherproof, by any means, either. Can you get a photo of that for us?

Currently I have removed any Sheetrock from the inside and I am in the process of doubling up the exterior

Before you do that, you really should confirm if that really is Homasote or not. That could be a problem.

My intentions are to finishing the installation of the Sheetrock to the outer shell and seal. Insulate with pink fluffy. Frame new inner shell walls so a 4" air gap is created.

So you are building your inner-leaf wall inside-out, and leaving a half inch gap between that and the existing outer-leaf wall? Is that it? That's about the only method I can think of that would leave you with a 4" air space. And with so much room available, wouldn't it be better to move the inner-leaf walls a little bit, so you can have a larger air gap? 4" is the minimum, but more is better.

Ceiling will be hung from hat channel attached to RSIC 1 clips fastened to the bottom cord of trusses per manufacturer recommended spacing. Then 2 layers of 5/8" rock with green glue between. I have specd the load requirements of the trusses and I'm fine.
I will be carrying the ceiling over the interior wall using backer rod and caulk so as not to create flanking situation

Something does not sound right there. Is there a reason why you don't want to have your inner-leaf ceiling resting directly on your inner-leaf walls? Clips and hat channel is an added extra expense that you could avoid, and getting your ceiling to work the way you described it is complicated, and requires precision work. Also, since the tops of your inner-leaf walls will not have any support like that, you'll need to add sway braces, which is yet another added expense, and more complication. It would be easier/faster/cheaper/better to just build your inner-leaf ceiling conventionally, on top of the inner-leaf walls, and completely eliminate any mechanical connect between the inner leaf and outer leaf.

Explanation: I intend to create a step or box if you will that runs around perimeter of entire room. This will be used as a chase for any wires, the top will likely be where I mount receptacles, I will include absorption inside and route channels the length of them.

There's a much easier and neater way of doing interior wiring in studios:

http://www.calcentron.com/Pages/fram-tr ... aceway.htm
http://www.export.legrand.com/EN/dlp-wa ... ng_95.html

I thought this would eliminate a corner around entire room,

I'm not sure I follow: Why would you want to eliminate a corner? There's no acoustic benefit to that.

Oh yes - I wanted to created an acoustic frame ...

The concept of having variable acoustics is good, but I'm not sure I get what you are trying to do with your "acoustic frame". Why not just put your treatment devices on the walls and ceiling, like most studios typically do?

I have a mini split that I just purchased.

What size? For a room with those dimensions, it would need to be pretty large. Did you do the math before you bought it, to size it correctly?

I will post pics in the post following this.

I'm looking forward to seeing those!

Also, please mention how much isolation you need (in decibels), and your estimate of your total budget for this build.


- Stuart -

Hello,

Thank you for your reply and my apologies for not replying for such a long period of time.

A lot of reconsidering, making decisions, then questioning the validity, changing my mind, etc, etc.

I was considering using my office and shop area to try and come up with plan for studio there, but have decided to lease that property at this time and have 4 weeks to get it cleaned out.

So here is where i am at this point.

I can not make up my mind if i should put my workshop and studio in the garage or build a purpose built space ( my brother in law has offered to sell me an acre) , or combine the 2 at my house.

I really want to have a space that can be exceptional for tracking drums, so if i do combine at my house i want to install a ridge beam (obviously jack hammer out some concrete and dig out for a footer/ pad and put some posts in) then sister rafters to the trusses and open it up.

I have stripped the garage walls and ceilings. The exterior board that i was referring to as 'Homasote" was my mistake. We have always called it by that name. It is fact it is some type of mdf I believe, brand name celotek. I will attach a picture. There is OSB at the corners of the building 1 sheet in (8') then the 'homosate' ( i will refer to it as exterior sheathing from this point). Garage has been there for 30 years and never an issue with moisture, still not. Roof was replaced a few years back and i have been in there during torrential rainstorms with flashlight inspecting for any sign of leakage - negative.

I have reinforced the exterior sheathing with Sheetrock that i removed from the walls and ceilings using construction adhesive. and a few screws to hold it in place till the glue dried. It is effectively one solid mass, i was worried about it vibrating. Tried bracing, and stapling with 18 ga. also screwing, but it would pull loose.

Copy on the sway bars, i have been in contact with a salesman (name escapes me at the moment) and will be purchasing them.

The mini split is a:
Pioneer Air Conditioner Invert-er+ Ductless Wall Mount Mini Split System Air Conditioner & Heat Pump Full Set, 36000 BTU 230V

I really hope someone is still around bc i could sure use someone's advice.

I have talked myself in and out of so many things at this point that i am severely confused again. I started re-reading Everest, and Rod's book's again. Just re-visiting everything at this point, a bit gun shy (I did the demo and caulking months back).
I have my bed against the wall, vertically, and sleep on the couch or floor at this point bc i have moved so much into my bedroom so that i can record and mix.

I will get pictures of the space up as well as some dimensions.

over all dimensions.

i will get something in sketchup soon.

thank uyou

Good to see that you are still around, and still considering the studio build!

I can not make up my mind if i should put my workshop and studio in the garage or build a purpose built space ( my brother in law has offered to sell me an acre) , or combine the 2 at my house.

Here's what I would do if I were facing that decision:

1) I would work out just how much space I need for my studio, considering the number of rooms, the purpose of each one, and the "rules of thumb" for figuring out the best size for each of them. After doing that, I would have a good estimate of the amount of floor area that I would need, and the height of each room. If that would fit inside the garage, then that's what I would do. If not, then I would design and build a building large enough to contain that.

2) Regardless of the above result, I would also use my sound level meter to calculate how much isolation I need for the studio, then decide on a specific construction method and set of building materials that will provide that level of isolation.

3) I would check the prices of those building materials, figure out how much of each I would need, figure out the labor costs, and arrive at a total estimated cost for building my studio. If that cost is within my budget, I would them proceed with Step #4. If the cost is too high for my budget, then I would bring my sights down a bit, reduce the size of my rooms, and go back to step #1

4) I would then sit down and design the studio in great detail, including all aspects (structure, isolation, treatment, HVAC, electrical, plumbing, etc.), and repeat step #3 with a more accurate and complete list of materials and tasks, to double check that I can afford to do this.

5) Then I would pick up my hammer for the very first time, and start building.

I have reinforced the exterior sheathing with Sheetrock that i removed from the walls and ceilings using construction adhesive. and a few screws to hold it in place till the glue dried. It is effectively one solid mass,

That was a mistake. You have reduced your maximum potential for isolation, since you have created one solid "blob" of mass that acts only as one unit, instead of having individual layers that act both alone and also together. It's a pity. Hopefully you don't need high isolation.

i was worried about it vibrating.

It is supposed to vibrate! And it still will. But now you have forced it to vibrate at a higher frequency than it would have, had you left it as individual layers, thus reducing your isolation.

Tried bracing, and stapling with 18 ga. also screwing, but it would pull loose

... which is what it was supposed to do!

The correct method for beefing up an existing stud framed wall is to cut the drywall into strips that fit between the studs, press it up against the existing sheathing, hold it in place with small cleats nailed sideways into the studs, and caulk around the edges with flexible non-hardening caulk (ideally proper acoustic sealant). That provides the increased mass, and the air-tight seal, while still allowing the individual layers to act individually, as well as acting together as a unit. If you really want excellent isolation, then you could use Green Glue in between the layers. Despite the name, Green Glue is not glue at all: it is a carefully manufactured visco-elastic acoustic damping compound, that works as a constrained layer damping element between the layers. Expensive, but effective.

Copy on the sway bars, i have been in contact with a salesman (name escapes me at the moment) and will be purchasing them.

Don't. Not yet. You won't even know if you need them or not until you know what construction technique and materials you will need (step #3), which is based on how much isolation you need (step #2). Only when you get to Step #4 will you be able to determine if you need sway braces, or not. And if it DOES turn out that you need them, you would only be able to determine what type of sway braces you will need, and what characteristics they should have (load capacity, resilience, deflection, size, number, location, etc.), after completing the entire deisgn and doing the necessary calculations. You can't just guess!

The mini split is a:
Pioneer Air Conditioner Invert-er+ Ductless Wall Mount Mini Split System Air Conditioner & Heat Pump Full Set, 36000 BTU 230V

Borderline. For a room with 1000 ft2 floor area and high ceilings, in a humid climate, that will be occupied by many people doing light to medium exercise (musicians jamming hard), plus instruments, equipment and lights, you will need about 48,000 BTU/hr on a hot day. If it was just a 1000 ft2 house or office, then you could get by with about 24,000 BTU/Hr, but for a recording studio / rehearsal space with a full band, plus WAGs and other hangers on, plus all the electrical load, you will need more.

I really hope someone is still around bc i could sure use someone's advice. I have talked myself in and out of so many things at this point that i am severely confused again. I started re-reading Everest, and Rod's book's again. Just re-visiting everything at this point, a bit gun shy (I did the demo and caulking months back).

Take your time, and work through the above steps. Feel free to document each step here on the forum, so we can look it over before you do anything, and hopefully help you avoid more mistakes.

You cannot do any design, let alone any construction, until you first know what you are trying to achieve, in terms of isolation and use. Determining how much isolation you need, in decibels, is the key to everything. That should be your very first item.

- Stuart -

wow,

thank you for the quick reply!!

Great to know you are here!!

I will be using green glue have 3 cases of the large tubes and three 5 gal pals also.

I think the ac will be good but if not i have 2 portable units. That can serve to help with extra hot days. 1 of them was sufficient last summer. I will just have to work that around any recording.

I should have let the Sheetrock pull lose inside the cavity? I thought the more energy it took to vibrate it the more lost to heat? Well I was going to put another layer of Sheetrock in the cavity, if it comes to that i can do so.

I did use backer rod and 100% silicone sealant to seal everything. I planed on using the green glue to seal the Sheetrock layers once i constructed the inner frame. I had read that the acoustic caulk was really just silicone. I knew the green glue didn't dry and that was how it worked, but thought the caulk was different or i would have used that.

Thank you for your wisdom, I will do exactly that!! Very much appreciated!!

I will be using green glue have 3 cases of the large tubes and three 5 gal pals also.

That's a good start, but won't be near enough. Think of this: Each sheet of drywall will use three entire tubes.

I think the ac will be good

With studio design, "thinking" something will work is never a good idea. Instead, you need to do the math and find out if it actually WILL work or not. You are going to be spending a large amount of money here, plus time, effort, and materials: It would be rather sad if you did all that, then at the end found out that it didn't work and that you needed to tear some of it down again to fix it.

but if not i have 2 portable units.

Portable air conditioners are not an option for a studio. For two main reasons: 1) They are very noisy, and 2) You need to cut a huge hole in the wall for the heat exhaust hose, and that implies totally trashing your isolation. You CANNOT have any holes in your walls. Isolation (sometimes incorrectly called "soundproofing") requires total air-tight seals around the complete room. If air can get through, then so can sound. It's hard enough isolating your fresh air ducts and stale air exhausts, without also adding the extra task of isolating your portable A/C heat duct.

That can serve to help with extra hot days. 1 of them was sufficient last summer. I will just have to work that around any recording.

Sorry, but that just is not an option. You are going to be spending upwards of US$ 100,000 to do this place, so rather than trying to save a tiny fraction of that by skimping on the HVAC, it would be much more sensible to do it right from the outset.

I should have let the Sheetrock pull lose inside the cavity? I thought the more energy it took to vibrate it the more lost to heat?

You seem to be misunderstanding how a 2-leaf MSM isolation wall works. There are several mechanisms working all at once, each one in a different are of the spectrum. That's why single-leaf walls are not much use for isolating studios, as there's only one mechanism at work: Mass Law. And Mass Law is not much use for high levels of isolation at reasonable cost.

I did use backer rod and 100% silicone sealant to seal everything.

Excellent!

I planed on using the green glue to seal the Sheetrock layers

Ummm.... you seem to be confusing two different products! Green Glue compound cannot be used to seal drywall! Nor can it be used as an adhesive. Green Glue compound serves one single purpose, alone: It is a visco-elastic polymer that acts as a constrained layer damping system when applied correctly BETWEEN two layers of a leaf. It works by damping some forms of resonance that occur in the leaf, notably bending waves. It is not a sealant. The Green Glue company does also manufacture an acoustic sealant, but that's a totally different product.

I had read that the acoustic caulk was really just silicone.

Green Glue compound is not silicon, and is not caulk. Yes, you can substitute silicon caulk (and some other types of caulk) for acoustic caulk, to a certain extent, but you cannot use caulk in place of Green Glue compound.

I knew the green glue didn't dry and that was how it worked,

Green Glue compound does not harden, correct, and that is part of how it works. But Green Glue compound is not the same as Green Glue acoustic sealant.

but thought the caulk was different or i would have used that.

Green Glue sealant (caulk) is a different product, and it's not all that good as it tends to shrink and crack when it cures. Green Glue compound, on the other hand, is excellent stuff. I do not recommend Green Glue caulk, but I sure do recommend Green Glue compound. It's expensive, but it is definitely worth while if you have the budget and the need.

- Stuart -

The tubes that I have are Green Glue brand Acoustic Caulk.

The 5 gal pals are the green glue which i will be using as a a damping compound between the layers of Sheetrock. I didn't mean seal them i meant between the layers of 5/8" Sheetrock that will be on the inner wall. I understand how it works. Based on my old plans I have almost enough per the manufactures specs, i have the dispensing tubes so i can be sure to use the proper amount per 4x8 sheet. But things may change.

The AC was calculated based on the cubic feet of the room (again the original plan - and also based off of 2 different people who used it in a space of that approx that size.) Yes I may have some things that create a bit more heat but not like the typical studio really, with many things being digital and self powered etc. Very small CPU, which was going to be in another room, as well as small amount of outboard gear, lights which produce very little heat.

The plan for the main tracking room was to have 2 large "sliding doors" (sort of) that were designed QRD 13 x2 per door. These "doors were going to open and close into a large reverb chamber. Which is effectively the other part of the garage. It is in there that i intended to run the AC units if needed. I was going to have a air transfer which would be made of an an echoic duct that would feed in and out iof this room.

As far as breaching the inner isolation, i have Fire-rated acoustic pipes that will come into the room in 3 spots. They then have a acoustic putty that seals around the wires inside the tube to effectively seal that breach. Hopefully they will be adequate to carry all of the wiring needed into the main room.


Again much of this seems to be a moot point since a re-design is in order.

Thank you again. I am grateful to have your advice and direction. And feel much better about things!!

I should show some plans but since we are going to re think this entire thing it seems a bit pointless until i know what i am doing for sure.

I am not sure what you mean about the single leaf system but i am going to have a second wall that is built so there will be MASS-Air-MASS - there will be a decoupled room within a room. I was simplify using the old Sheetrock to double the sheathing of the exterior leaf but without taking down the siding and doing it from the inside. So i did it from inside the stud bay leaving the room for the insulation and then would be the air space and the next wall. Like it is detailed in Rod's book.

i will be finishing each layer of Sheetrock the way it should be done - i think, then using silicone caulk (based on your recommendation regarding the green glue brand CAULK). Then using green glue dampening compound (which is what i have in the 5 GAL PALS not the tubes) between per manufacturers specs ( 2 tubes per 4x8 sheet), and i will then screw the second layer of Sheetrock, that i will run in the opposite direction and, being sure not to screw them into the studs (the second layer) i will then finish it [the second layer of rock] (by finish i mean - tape mud and sand, mud, sand, etc) and then seal it with silicone caulk.

Is this the correct way to do it?

forgive my crude sketch up abilities.

Also i sealed the celotx then sealed again after i added the Sheetrock.
(with 100% silicone)

then i planned on leaving a space and constructing another wall leaving it open on the side facing this leaf and using 2 layers of 5/8" rock with green glue dampening compound between

would you recommend a third layer of drywall on that exterior wall from the inside? I can screw that into the drywall behind it. Also i have 4 5 gal pals of Sheetrock sealer left from a job a couple months back. It will likely sit on my shelves until it expires if i dont find a use for it. So even though it may not be a great bang for the buck it is actually well worth using if it provides even the smallest increase in isolation.

Again this all assumes that we decide to proceed in this space.

The Rules of thumb you refer to - would you mean looking at optimal room sizes, septmeyer, Loudain (SP??) and / or the Bolt Area and trying to find sizes that create a good match, or close enough while still maintaining an adequate volume (i.e. dont sacrifice room volume just top meet a preferred room ratio)?

And then also the ideal ratio of CR to LV ? Cant remember off the top of my head but i will look up, but i believe it was 5-8?? That may have had something to do with sub woofer sizes and something ??

As well as considering the spaces necessary between the leafs, or any other factor that would lead to a room of dimension X requiring an actual dimensions of, for instance, X+Y.

See where the best fit is and then determine if that is feasible for the overall size of the space?

Thank You
Hope your enjoying the weekend!!

would you recommend a third layer of drywall on that exterior wall from the inside?

It might or might not be necessary. That all depends on how much isolation you need. As I said a couple of times already: "You cannot do any design, let alone any construction, until you first know what you are trying to achieve, in terms of isolation and use. Determining how much isolation you need, in decibels, is the key to everything. That should be your very first item.". That's the key. There are many construction techniques and building materials that can be used to achieve various levels of isolation. Until you know what level of isolation you need, you will not know which construction technique and building materials you will need.

Think of it like this: You need to transport yourself from point "A" on the surface of the planet, to point "B". That's all you are telling me right now. I'm asking you: "How fast to you need to go? What's the distance between those points? Which direction do you need to go?" And all you are saying in response, is "Should I put on another jacket, in case it gets cold on my trip?". You aren't asking the right questions. If you are going on a trip, you FIRST need to know what the heading is (Eg: "due north" or "south west" or "123° magnetic bearing"). THEN you need to know exactly how far you are going (Eg: "324 feet" or "17 miles" or "8,000 km"). And finally, you need to say how fast you need to go (Eg: "31 furlongs per fortnight", or "2 miles per minute" or "580 kilometers per hour". Only then will you be able to take your journey and arrive where you need to go, on time. When you know all of that, only then can you decide if the best mode of transport is a bicycle, a car, a train, a jet plane, a horse, or just your own two feet.

The same applies here: First, define how many decibels of isolation you need, in real world numbers. Then based on that, we can move on to the next step.

I can screw that into the drywall behind it.

As I mentioned before: "The correct method for beefing up an existing stud framed wall is to cut the drywall into strips that fit between the studs, press it up against the existing sheathing, hold it in place with small cleats nailed sideways into the studs, and caulk around the edges with flexible non-hardening caulk (ideally proper acoustic sealant)."

Also i have 4 5 gal pals of Sheetrock sealer left from a job a couple months back.

That will probably be useful for your inner-leaf drywall. I'd save it for that.

So even though it may not be a great bang for the buck it is actually well worth using if it provides even the smallest increase in isolation.

It will help a bit yes. Not a huge amount, but some. If you already have it, then it's definitely worth using. Anything you can do to seal your leaves better, is good.

The Rules of thumb you refer to - would you mean looking at optimal room sizes, septmeyer, Loudain (SP??) and / or the Bolt Area

I would start with the recommended floor area for control rooms ("critical listening rooms"), as specified in documents such as ITU BS.1116-3, EBU Tech-3296, and similar ones from the AES, as well as companies like Dobly, Genelec, etc. They all pretty much agree on the suggested minimum areas for various uses and configurations of control rooms. Download those, and check them out.

Sepmeyer, Louden. and Bolt are not about room sizes: They are about the relationship between the three dimensions of rectangular rooms. Sepmeyer and Louden (as well as others) each discovered several such ratios that work well for good modal distribution. Bolt took that further, and identified an area, or zone, or set of room ratios that he predicted would give reasonably good results, and he graphed that on an X-Y plot, for a room with a fixed height. Spemyer and Louden ratios fall mostly within the "Bolt Area".

So, once you have identified the floor area that you will need for your control room, and the available maximum height for your inner-leaf ceiling, you can use those ratios to come up with a set of dimensions that makes sense for your control room. Or several such sets, then later choose the one that is best for you, based on other criteria that might come along.

to find sizes that create a good match, or close enough while still maintaining an adequate volume (i.e. dont sacrifice room volume just top meet a preferred room ratio)?

That's roughly the idea, yes. In general, more volume is preferable to a better ratio, for small rooms. If you have lots of space, and need high precision acoustics, then you might want to optimize for the best possible ratio, even if it means losing a bit of volume, as long as you still end up with more than enough volume. But for very small control rooms where the maximum volume is already borderline, then it's better not to lose more of that precious volume just to get a great ratio. Better to settle for a reasonable ratio and more volume.

As with most things in studio design, there will be trade-offs here.

And then also the ideal ratio of CR to LV

I think you mean "LR" not "LV", but the ratio should be such that the LR is around five times the volume of the CR, or even greater if possible. Hopefully not less than three times.

That may have had something to do with sub woofer sizes and something ??

No. It's about "reverb tails". Since your live room is much larger, it will have much longer natural reverb times: Sound will die away relatively slowly in the LR (which is one reason why it is called the "live" room). You need to be able to hear that slow "fade away" or "tail" when you are listening to the LR mics on the main speakers in the CR, so you can hear how the ambient sound of the live room works with whatever it is you are recording. If the LR and CR are similar in size (volume), then the reverb "tails" in both rooms will also be similar, and you won't be able to hear the LR tails when you listen in the CR. The tails in the CR will mask, or disguise, or hide, or overpower the tails from the LR. So you won't be able to hear the subtleties of the ambient sound picked up by your mics. And that's a bad thing. Any time that your studio prevents you from hearing something that is actually in the mix, it means that you did not deal with it, even though others might hear it later. If you can't hear it, you can't mix it. So your song will go out the door and be played on many other sound systems all over the place, and the people listening to those sound systems will potentially hear things that you never heard! Obviously, that's not a good situation. You need a studio that tells you the truth, and disguises nothing. It must be designed such that the ONLY thing you hear as you sit at the mix position, is the pure, clear, pristine direct sound coming from your speakers, followed by a carefully controlled and very neutral, low-level ambient decay, that makes it pleasant to work in the room.

That's the goal. But rooms like that don't just "happen" by pure luck and chance, when nailing a few boards to some studs and joists. They need to be very carefully planned to achieve that, then carefully built. Like this one, for example: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471

As well as considering the spaces necessary between the leafs,

The depth of the cavity between the leaves of an isolation system is part of what determines the resonant frequency of that system. You need to tune that frequency to be at least one octave lower than the lowest frequency you need to isolate.

See where the best fit is and then determine if that is feasible for the overall size of the space?

Start with the control room: Make it the best size and ratio you can, based on the guidelines in the documents I mentioned. Then design a live room that fits in with that, and meet's the "5 times the volume" guideline. See how that works. If you can't get that to work, then shrink the CR a bit, to a slightly smaller size/ratio, and try again. Keep in trying various combinations until you have a workable compromise. Then see where you can fit in the other rooms that you want around those two, while still allowing for isolation walls, good sight lines between rooms, intelligent access paths and traffic flow, good isolation, good storage access, good lighting, proper HVAC, doors that are wide enough and don't clash, good structural integrity, good construction practices, etc. Designing a studio takes time, and dedication, and suitable background knowledge of both acoustics and construction.

- Stuart -

again thank you for your time and thoughts - they are so very valuable to my process.

I absolutely understand what you are saying re: determining what isolation I need, rooms sizes, etc, as the first step of the process. I only asked about the 3rd layer bc i am very tight on space right now and have a dumpster going out this week, so wanted to know if that was an absolute for any reason , and if the answer was no i was going to remove it as debris.

I have been reading the documents regarding size and other considerations for a critical listening room.

Just wanted to touch base and express my gratitude. I will be making some measurements, as well as trying to figure out the dimensions of the rooms i will need this week. I am going to begin moving out of my current office and shop area starting today.

My initial thoughts, after reading the recommendations in the above mentioned documents, are that i will not likely be able to meet either the minimum of 30 m2 or the a CR:LR ratio of between 1: (5-8).
I have run through a number of sizes trying to meet the various recommendations regarding room sizes and their dimension relationships. If i could ask? In making considerations to sacrifice certain things for others. Would you consider the 30 m2 to be paramount? If so i dont think i would be able to have a CR:LR ratio of much more than 1 :(2-3), and knowing would change my thinking process.
Perhaps I should not even be asking this question yet. But if the size of the space negates certain poossibilities it would save wasted time considering options that are simply not feasible.

Thank You,

-J

Would you consider the 30 m2 to be paramount?

30m2 is more for multi-channel rooms, (5.1, 7.1, etc). BS.1116-3 suggests 20m2 for normal stereo rooms (2.0, 2.1). That's the smallest recommendation, but even then it is possible to go smaller. I have designed a few rooms around 18 m2, and that can work out well. John has done rooms inside a shipping container! I'm working on one right now that is really tight, at about 15m2, but that's about the limit, and that's very problematic, since there's not much modal support in the low end at all. So try to go for around 20m2 or a tad less for your CR.

For the LR: Don't forget that the relationship between CR an LR is volume, not area! If you can get the ceiling twice as high in the LR than the ceiling of the CR, then you can have a much smaller floor area. For example, if you go with 20m2 and a 2.5m height in the CR, that gives you 50m3 volume, then you could go with 50 m2 and a 5m ceiling in the LR, to get 250 m3m which gives you the 5:1 ratio of volume. Or you could go maybe 60m2 and 4m ceiling in the LR, for 240m3, which is still plenty close enough.

Perhaps I should not even be asking this question yet

Ask any question you want! It helps to have all your ducks lined up in advance. Get as many answers and as much info as you can, then go through the process and see what comes out. Having answers to future questions will save you time, and get you better oriented in dealing with the big picture.

- Stuart -

Great! Thank you again for such a quick reply. It seemed to me that many control rooms i have either read about, or come across in some way, that the dimensions were often a bit smaller that 30 m2. 20m2 is actually quite doable!!

Also i was not completely positive if that was area or volume, so much thanks for saving me time there as well!! I was thinking that would be a nice way to maximize that relationship (larger value of h).

Thanks again!!

I actually thought about the shipping container thing for a brief second ( i have 2 but they are full !!) but when i looked at the ceiling heights and the real feasibility of stacking them and cutting into them without structural degradation, it seemed that in the end it may not be that much less expensive of an option; at least where the height is a constraint.

OK - Take Care!