John Sayers' Recording Studio Design Forum

I think you are totally misunderstanding what you have seen on John's design! You are confusing the interior treatment surfaces of the room, with the inner-leaf!!!

In other words, what you are showing in your diagram is only the final surfaces that you would see of the acoustic treatment INSIDE the room. You are NOT showing the most important thing, which is the actual inner-leaf of the MSM isolation system. Most of the treatment surfaces that you show there are simply cloth or slot walls....

Maybe you need to take another look at the model that you copied that from, and try to understand better each of the materials and surfaces.

My suggestion was to put the two vocal booths BETWEEN the two studios, not the other way around!

What is the density of your plaster blocks? (kg/m3) There are many ways of making plaster blocks, so the density could vary wildly. I'd need to know the density of the specific blocks you are planning to use.

Ummmm.... I think you are several months away from being able to order materials!!!! You've been working on this for a couple of weeks already, and you don't even have a viable basic layout, let alone a detailed plan. And now it seems that you are having a problem understanding some of the basic acoustic design concepts used in the studios that you are trying to copy. Maybe this sounds a little harsh, but you are not ready to build anything yet. If you build something based on the way you are going now, it is going to be a disaster. If I were you, I would spend a couple of weeks studying the basics of acoustics and studio design, using the forum and the usual books that we always recommend here, then spend another couple of weeks doing your basic layout, based on the principles that you learn, then spend another couple of weeks refining that layout, and drawing the actual plans, with the correct materials in the correct places. And only then should you start thinking about buying materials.

That's not enough for what you need. You say that you need high isolation between the rooms, so that's not going to do what you need.. The ceiling must be done to the same level as the walls: Same mass on each leaf, same air gap. If not, then you are wasting money on the walls! If you build walls that isolate to 65 dB and a ceiling that isolates to 40 dB, then the entire final isolation of your room is about 40 dB.

No. Increasing the density of the insulation on the cavity will not improve isolation, and in fact it could REDUCE isolation. The densities you find recommended here are on the forum are already the optimum densities, and have been tested many times in acoustic laboratories. That's the best. If you uses something else, it will be worse, not better.

Not necessarily. There are ways of compensating for reduced air gaps.

Exactly. Higher density is worse for low frequencies.

Optimum density! around 30 kg/m3 for fiberglass, or around 50 kg/m3 for mineral wool. Those are optimum densities, for most acoustic applications. You can use other densities in some places, if you understand what you are doing.

A 2cm air gap is WAAAAY to small. Do not ever have an air gap of less than 10 cm. Less than that and the MSM frequency rises really fast, and you can no longer compensate with mass, as the amount of mass you need is thicker than the air space you save...

But you also seem to be confused about the term "air gap". In acoustics, when we talk about the "air gap" in some type of device (such as an MSM wall, for example), then it is still considered to be "air" even if it has insulation in it. Fiberglass an mineral wool are mostly air anyway!

Did you check the structural characteristics of those joists? (not studs: joists. You are talking about the ceiling here, so they are joists, not studs). I'm not sure if you can support several tons of drywall on 2x4 studs spanning those distances.... Did your structural engineer say you could do that? What deflection are you figuring? You are talking about spanning more than 4 meters, maybe as much as 5 and a half meters? I don't see how you can do that with such a load on 2x4's!!!!! What type of wood did you have in mind?

And what are you talking about "outer part of that leaf"??? A leaf is a leaf: There is no "inner" or "outer" part to it. It simply consists of one or more layers of dense material. so the leaf IS 3 x 16mm drywall, period. That's it. That IS the leaf. There is no more to it than that.

That depends on your design concept, and the reason for tilting it, and how much you tilt it! If you are basing your room on the RFZ or CID concepts, then yes, you can tilt it, but then you need to calculate the correct angle. If not, then you still can tilt it if you want, but you'll need to use a cloud for treatment anyway, most likely. Rooms can be built rectangular, or they can be built with splayed surfaces. But those are two different design concepts, and need two different approaches to how the surfaces are treated.

And in any case, you should only angle the ceiling UP, never DOWN. In other words, the lowest point of the ceiling must be over the speakers, at the front of the room, and the highest point must be over the sofa, at the rear of the room.

(13cm insulation + 10mm plasterboard + 2cm air). I would expect something more like 10 to 15cm air-plus-insualtion, then 2 or 3 layers of 16mm plasterboard.

Anyway, the basic impression that I get here is that you are still rushing, and seem to be in a big hurry to build this place when you are nowhere near ready for that yet. If you don't have the time or the knowledge to design this yourself, then maybe you should hire someone to do it for you. Send John an e-mail or PM, and ask him for a quote. This is what he does for a living! How knows how to make the best use of space, and how to get the best acoustics and isolation in there, and get you as studio that not only sounds great, but also looks great! He's been doing it for years, and will certainly not make the mistakes that you seem to be making! He designs top-class studios around the world, and your project is exactly the kind of thing he does really well. It would be much better, and probably cheaper in the end, to pay the design fee and get it done properly. If you do it wrong, how much will it cost you in lost income of nobody wants to work in your studio because it sounds bad and the mixes don't work? How much could it cost you to tear it down and re-build it right?

Or, if you prefer to do it yourself, then I'd really suggest that you buy the "Master Handbook of Acoustics" and also Rod's book "Home Recording Studio: Build it like the Pros". Those two will teach you the theory and practice of designing studios, and once you have read them and understood them, you should be able to get started. Then you can post your design here on the forum, for folks to comment on (Rod himself posts on the forum occasionally), and perfect it, based on the comments and suggestions, just like you are doing now. That will work fine too, and it is what the forum is here for! But it takes a lot longer.


- Stuart -

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

You are right, there is just the inside room on this design because we were speaking of the symmetry of the control room.
I understood the concept properly, inner wall is pretty clear with 3x16mm plasterboard on studs. Rest assure that I'll be posting another layout design soon showing eveything : outer wall, inner wall and inside treatment.



yes, I got it, but I don't succeed in doing that without loosing too much space or without ending up with small or asymetric control rooms



The ones we are planning to use are 850 Kg/m3. is that enough or shall we seek for some with higher density ?



I share your opinion, unfortunately we have 400 m2 of offices to build (including those 2 studios) and we can only stay in our current offices until the 15th of july.
So we're in a rush
I got contractors to demolish and build, but I need to explain them exactly what they'll have to do.
So basically, I wish I could wait and take some weeks to study the layout and learn, but I just can't, I'm gonna need to learn fast !
At least I have hints & advices from you, thank you for that !



So you are suggesting to do the same as the walls :
3 x 16mm plasterboard on 95 x 35 studs. And the plasterboard shall be 100mm away of the actual ceiling, same as the plasterboards of the inner wall being 100mm away of the outer wall.
Shall we just caulk the actual ceiling with coating and that's it ?

I saw some thread where they also put some insulation directly under the ceiling + a 10mm plasterboard before the air space that they fill with another insulation. Then only they do the 3 (or less) x 16mm plasterboards on joist which makes the new ceiling to lay on the inner walls.
To me this is like doing a 3 leafs instead of 2 because there is air twice, so that's not to follow right ?

This was the thread : viewtopic.php?f=2&t=9201
they put first insulation + 10mm plasterboard between the joist of the ceiling, then there is air, then new plasterboard and wood joist + insulation and again plasterboard.
Then even after that they have anothe "false ceiling" (inclined) that you can see on page 3 of the thread.
all this is really confusing for me !



ok, that's what I call a clear answer ! great thanks



good, could you enlighten me on that ?
maybe I can save some space under my existing ceiling concrete joist



hey, for once I am right



ok, another clean & clear answer !! great



ok, got it 10cm, we'll keep that.



ok, so how much amount of insulation in the 10cm airgap do we fill with the 50 Kg/m3 mineral wool ? 50% = 5cm ? more ?



yes that's something I need to check with the contractor, they have an architect that can help me with that
maybe a different type of wood will be needed as you suggested. I will ask them.



I meant exterior part of the inner walls.



the idea is to tilt the ceiling because the concrete T joist of the current ceiling is around 30cm height. so instead of having the inner ceiling below that all the time (below from 100mm air + 3x16mm + 95mm) I wanted this to be the lower point and tilt up when there is no 30cm concrete un-movable joist.
that's why I asked about compensating for reduced air gaps because if I can tilt AND reduce the 100mm air gap below the concrete joist, it would be GREAT !.



ok, so Studio D control room needs to be reversed, because the concrete T joist is on the right hand side (you can see it with dash - - - - on the layout)



ok, got it, same as the walls.



I know, I did but I have only a 2500/3000 USD budget left in my construction quote and John is unfortunately more expensive as a consultant
Don't get me wrong, John's experience is of course worth what he asks, but as we are financing all this on our own money, not with any group or funds to back us up financially, we have to be carreful about all expenses.



I don't prefer to do it myself believe me, but I have no other choice hopefully you will keep giving me a couple of hints and advices, and we can have a good result !

best regards,
stéphane

Hi folks and Stuart,

As Stuart suggested, I read Rod's book "Home Recording Studio: Build it like the Pros" and took a week to work again on the layout and the MAM, here are the results !



I have 3 new possible layouts. Note that first studio does not need a vocal booth. it's just a control room for production/remixes.
I have managed to insert the vocal room for the second studio in the middle between the 2 studios and I have respected a good ratio (at least we're close to them).







I have also oriented the room in the right direction so the low ceiling part will be above the speakers.



Now left studio had no ceiling problem (no joist) and right studio just has one joist where I need to compensate to reduce air gap below the joist. Do you have any clue on how to handle that ?

let me know also which layout do you think works the best ? 1, 2 or 3 ??

speak soon, best regards,
stéphane

Hi Folks !

Demolishing has started, so much pipes !
I am lucky, they are not on the side of the studios but on the opposite wall of the space so I won't have issues with insulation and sound transmission to those pipes.

I'll send new pics of the demolition soon, on the side of the studios !

best,
stéphane

Hello !

More demolitions pics today.

This is where one of the studio will be. Note the existing ceiling and the existing exterior wall.

Exterior wall will need some caulking to avoid air cavities between the stones. Since we're in a basement and we might have humidity (not in the studio but in the air cavity of the M/A/M) we are thinking about caulking with concrete instead of plaster.

Ceiling might need some mass to be directly applied on it, so we're thinking to apply 1 or 2 x 16mm plasterboards to give it more mass as those terra cotta ceiling pavements are empty inside (you can see it on top right corner pic).



Now more demolition pics of the rest of the space, where our offices will be :



Stuart, bottom right pic is for you !!

best,
stéphane

Pretty much the same thing: the type of plaster you'd use there is basically just a mixture of sand and cement, That's a good way to seal it, and it adds some mass, too.

But after you are done, and the cement is fully dry, you need to seal the surface of the cement with a sealant designed for that purpose: cement is porous, so it needs to be sealed, for acoustic reasons.


Sacrilege!!!!


- Stuart -

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