John Sayers' Recording Studio Design Forum

I have found reading through this forum invaluable and thought having read through Adam's build that you guys may well offer some assistance in any unforeseen areas
I've been prompted by having been told (by a studio designer) that my intention of using core filled block work is futile and that I might as well no have an external wall at all! As I am about to order the blocks I am now trippin on whether this needs to be changed or not I understand the acoustic properties of the blocks as opposed to a solid brick etc but... any input appreciated.
Work still proceeds pending these decisions
1.excavations Dec2010 for footing (70m2) in two isolated slabs


2. concept plans - thought i'd best add these



3. footing poured after breaking of the drought and digging them out hmmm...several times. BTW I'm on volcanic rock! 2.5k of rock breaker to get started, budget blowout already



4. Due to the rock, I had to add a strip footing


5. Proofing for rising damp...ironically between the almost nonstop RAIN!!


6. Slab preparation, packing sand


7. Form work done


8. Steel in...night before the pour


9. After about 7 months of drought breaking rain... we rise above the ground and the slab is poured


10. stripped & time for a breather

This is probably a bit late to tell you (but you only just posted, so we couldn't tell you beforehand!), but there are many issues with that design that do not bode well for success. For starters, the control room seems to be square, perhaps even a cube, which is about the worst possible shape. Second is sight-lines: You don't have full visibility of the live room from the mix position. Third is access paths: In order to get from the control room to the live room, you have to walk through the lounge! Impractical, especially for tasks such as micing drums or other complicated instruments. To make matters worse, there is no isolation door on the live room when going through the lounge, so you actually don't have proper isolation at all: it's going to be loud. Add to that that you are using only 13mm drywall, instead of 16mm...

There are a few other issues too (such as the size of the window and positioning of speakers, bass traps, etc.)

But getting back to your original question:
Wait, let me get this straight: A studio designer told you that large amounts of high density rigid mass as part of an MSM system are no use for isolating a studio? Remind me never to ask that guy to help design any studios for me... !

In other words, there is nothing at all wrong with that. You are doing fine with that concept. Concrete blocks filled with sand or mortar, and properly sealed, will make an excellent outer leaf. Combine that with an inner leaf of a couple of layers of drywall over a good cavity, filled with suitable insulation, and that's a darn good isolation wall... You might want to suggest that your "studio designer" should take a look at IR-586, which deals with exactly that. It shows that isolation levels in the high 60's are easily attainable, and even the low 70's without too much trouble. With one structure, they even got 79! That's amazingly good isolation! Most folks here are happy to get in the high 50's or low 60's for their studios, so you should be about an order of magnitude better, if you do it right. (The designer might also want to take a look at BRN-217...)

I'm wondering if this is the same "designer" who suggested a square control room, access paths through the lounge, and no second isolation door on the live room... ?



- Stuart -

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

"I understand the acoustic properties of the blocks as opposed to a solid brick"

Well, that isn't going to be an issue, since the footer of this structure is bonded together. Now in a small build this wouldn't be an issue, but in as large a build as this is...and I have to tell you like we tell everyone else, you should have came here first, but with this kind of build, I would have looked for a total decoupling of the slabs, and you do not have that.

The foundation is the primary connection that you want to decouple from the start.

I'm just sayin'

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

You know, I'm getting a little confused here! In your other posts on a different thread but about the same build, you mentioned that this is a brick veneer design ("unfortunately the design is a veneer construction"), and that you'll be using resilient wall ties for that. But when I look at the plans you posted, I don't see any veneer at all! I just see "140mm concrete block" then "applied finish as specified", which looks to be something very thin, like stucco or something. How come your plans do not show the veneer design or the resilient ties? What else do the plans not show?

Then, to confuse matters even more, you also said "further TL to be gained with internal wall construction of barrierboard with fyrcheck & ply." but the plans do not show that either! The plans specify "2 layers Soundcheck plasterboard with Green Glue".

Did you maybe post the WRONG plans? Because the don't match anything at all you said on the other thread!


You also said "This is probably where the concern lie with the blocks needing to be offering a good degree of TL", but that makes no sense. Neither the blocks by themselves nor the drywall by itself will offer a "good degree of TL". If that's what you thought, then you are under a basic misconception. This is not two separate walls each doing their own thing: this is a SYSTEM! The blocks and the drywall act together as a tuned system to isolate. They are designed to work together, as a fully decoupled tuned MSM system, which isolates much better than any of the individual pieces. The blocks and drywall for a resonant system, which is tuned to a specific frequency: At that frequency (F0) the wall does not isolate very well at all. It starts isolating at 1.4 times F0, and isolates well at 2 times F0. For this reason, the resonant frequency was chosen to be well below the lowest frequency that you need to isolate. Your plans aren't very clear, and I can't make out the dimensions, so I can't calculate the resonance, but it looks like it is designed for something like 30 to 40 Hz or so, at a rough guess, so it will isolates above about 70 Hz.

Anyway, the point is not the the blocks have to do all of the isolating themselves, but rather that they provide exactly what is needed to do their job as part of the resonant isolation system.

The issues I see in your design are about layout and usage, not so much about isolation (although Brien brought up a very important point there, about your slabs not being separate and independent when they could have been, giving you really good isolation). To me, it seems you are worried about the wrong things! Your isolation plan looks like it should work, and your blocks are fine, but your actual studio layout and the other issues I mentioned are where your design falls apart.

Anyway, please clarify if those plans that you posted are the actual plans that are being used to build your place, or not. And if those are the plans, then how come they do not match your description in the other thread?


- Stuart

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

Thank you for your help gents, I have been away 4 days. I hope I can clear a few things up. The plans are a tad behind in terms of whats being built. I hear you on the pragmatics of the layout however it's not a commercial op and I'm happy to live with it. The viewing widow is ok too as the other end is basically to store mobile acoustics (booth, partitions etc, a & a baby grand ) The control room doesn't show the internal layout that is not a cube once acoustically completed The soundchek board is 'sound/acoustic' specific and actually offers 13kg of mass as opposed to the fyrcheks 12.5. I know this argument is a common one and I have not yet settled on which way I am going just as yet. I am leaning this way, with the inclusion of barrier board:

It is a brick veneer construction, 140mmCore filled block-50mm cavity-90mm stud wall-32kg ins-drywall, the veneer is probably hard to see on the plans posted as b/c of the res. there are some standard details on them though
Do you still think this is ok as per your first post Stuart?

The slab isolation may be difficult to make out but it is there, they're 2 independent slabs

The framing is almost done with the block work in the original question pending
Thanks again

I thought i'd add a little on the barrier board too, see what others think of it. Its at this link http://www.soundblock.com.au/soundproof_walls.htm
Clicking on the 'technical specs' at this link will give construction details
cheers

"The slab isolation may be difficult to make out but it is there, they're 2 independent slabs "

No sir they are not. They are bonded at the footer level and to add insult to injury the framing bonds the structure again...

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

G'day Brien,
yes the slabs (plural) as they is certainly two! share a footing but this is unlikely to cause any real issue as the strip footing & packing sand are a substantial TL. As for the frames i'm not quite sure what you mean exactly. There is some temporary fixings ATM but these will be removed and only resilient ties will be employed where required by regs http://www.studcosystems.com.au/sound-isolation.html All the plates are on 1/4" impactmat

Ummmm... and what about flanking? If you have a solid concrete connection between two slabs, then they are NOT decoupled, and tnhere WILL be flanking, regardless of anything else.

I started reading the info about that barrier board stuff, but the first thing I saw as this:
Wow! So it can reduce levels by a bit less than 3 decibels!? Amazing! Sorry, but I didn't bother reading any further than that: when you see sound reduction levels quoted as percentages, you already know that you are looking at marketing hype, not actual acoustic information. I found no technical information at all there, but I have to admit that after reading the above, I didn't try very hard. So if there actually are reports on testing done by recognized, reputable independent acoustic labs, please post the direct link to that. And if they don't proved that kind of info, then it's safe to say that you can ignore such a product (or maybe substitute a sandwich made of old carpets and egg-crates: the results should be similar).

I'm not sure I understand: From the photos it is clear that the walls are already in place, but you say that you plan to build more walls to change the room shape, thus reducing the already small dimensions, and also creating 3-leaf walls? Maybe you can explain that in more detail, and provide a diagram of how the room will actually be built. And also post more photos, from different angles, since it's hard to tell form just one photo what you actually have there.

Why? Did you also use isolated anchor bolts to attach the framing to the slabs?

Then why did you post them???? It seems rather pointless asking for commentary on something that you are NOT actually building, while not posting the plans of what you really ARE building! How can you expect valid, useful answers from that situation? That would be kind of like taking my car to the mechanic, when in reality the problem is actually in my wife's car...



So maybe you could post the final, approved plans of what you are ACTUALLY building, plus some additional photos, to get a better idea of where you are.

Also, you seem to be aiming for high isolation here, but you never actually stated your goal: what level of isolation are you building for?


- Stuart -

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

OK, I'll bite on this one. Lets just go ahead and say that as far as the exterior goes, the slab and footers are bonded but present no issue in that respect.

But lets investigate what it is you are doing. The goal is a mass/spring/mass enclosure right? Based on that your guys are going to decouple the interio framing and keep that aspect in focus, I get it.

But why, with a purpose built room have you guys not included, at the least, an interior slab that is not connected to the exterior slab/footer, the decoupling that you will include in the framing?

Why go thru all the trouble of doing this on the lightweight wooden framing, but dismiss at the foundation level that there is the real opportunity for sound to move thru the steel rods and concrete from both sides of the room?

Sound moves faster thru steel, then to concrete, then to wood...so it makes no sense, there again as a purpose built room Specifically for sound centered endeavors, that these decoupling methods were not included, like the concrete was heavy enough that it would not be an issue?

Do not mistake me, I like what you are doing, it looks good, but I am getting the thinking here that some more pictures of the next phase are going to show up, and we are going to scratch our collective heads asking "why did he do that and not at least ask for an opinion one way or the other?"

Still, we are cool, but I would take a few minutes to review the plans, discuss what it is you are doing and ALWAYS be mindful, and make the trades involved mindful, that you are building a structure designed for isolating sound, this is not a house so everything matters and everything changes.

Peas!

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

Sorry to hear about your wifes' car Stuart

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

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

opinions as to the use of such material?
http://www.thermotec.com.au/index.php?p ... insulation
ie: as a part of a wall, ceiling construction

Thanks for he words of encouragement Brien. I hear you guys and to be honest I'd had my fill of often conflicting opinions and the varing input of the many experts too... I appreciate what you guys are saying though. As I have had some planing restrictions I have to deal with the build as it stands and yes I do have some similar concerns as to those you mention and some mistakes have been made. I am however doing what I can with what i have to bring the construction to fruition and with the desired results - ie containment; for the sanity of my family & neighbours.
I am experimenting somewhat with various materials that dare I say, in theory should provide me with the desired results.
I'd like to continue to post more info on what I am doing and how im trying to achieve it, welcoming constructive criticisms while minimizing deflating 'shit caning' as its a hard enough road as is as anyone whose done this before will attest and the skin can get a little thin Anyway
cheers

Can I get some opinions on doors here, specifically double paired doors especially relating to the center seal. ie the astragal or meeting stile of the doors and as to weather it is a viable option?

I've attached a jamb spec as such, paying particular attention to the 4 door configuration. Is it a much better idea to go with a 2 larger door set up (2 x 1200)?
Thanks
Anthony