new studio design... would you please help an ignorant MVO?

Posted: Tue Nov 25, 2008 1:20 am

Hi everyone. First let me introduce myself - my name is Pierre, I am French but have lived in London for the last 15 years, I spend my life in recording studios but I am ignorant of all things acoustic. In other words, I am a voiceover artist - and as I'm of the male variety that makes me a male voiceover artist, otherwise known as MVO (in case you wondered what it meant in the title of this post!)

We're about to move to the South West of France, to a barn in the middle of the fields we bought which is being renovated, and I will have my own recording studio there. I intend to use it not only to record my own sessions for my clients but also to hire it out to clients wanting it either to voice or to mix, for both the VO and the music markets (we will be not far from a big city called Toulouse and the music scene is quite big in the South West).

I gathered information from Rod Gervais's book (absolutely invaluable practical info, tips and advice in it), my sound engineers friends, as well as observing how the studios are designed. The construction bit is not difficult for me (I used to be a builder/carpenter in a previous life) but getting the acoustics right is. Very.

I have drawn a plan (below) based on the info gathered and would love nothing better than to be told that I am an ignorant phillistine and that this shouldn't be done like this but like that, that this is so wrong but it would be so right like that, etc.

The links for the materials mentionned are:

Regupol E48 and E4515
http://www.bbs-ltd.com/acoustic_regupol.htm

Rockwool Rocksol Pro (in French)
http://www.rockwool.fr/sw464.asp?sid=94

Door drop bottom threshold
http://www.lorientuk.com/products/integrity-architectural-seals/6000-series-magnetic-seals/

Placo Phonique (in French)
http://www.placo.fr/bpb_fr/ProduitsOuvrages/catalog/sproduit.aspx?ProductID=P80900000PP

To view the plan in full size:
http://www.sbcelebs.tv/images/TheFrenchVoice_studio-plan.jpg
Thank you in advance for your much valued input!

Posted: Tue Nov 25, 2008 1:36 am

By the way sorry about the size of the plan, it's just that I've included a lot of details which wouldn't show if it was smaller...

Posted: Tue Nov 25, 2008 1:37 am

*gets an eye injury from side scrolling*

Posted: Tue Nov 25, 2008 2:03 am

It really was too big, sorry for the eye sore Greener... I edited my post with a smaller pic size, to view the full size go to http://www.sbcelebs.tv/images/TheFrenchVoice_studio-plan.jpg and click on the picture to magnify it... thanks!

Posted: Tue Nov 25, 2008 3:02 am

Renovating a barn in the fields outside Toulouse... I am so jealouse. Razz

I note your barn has 24inch thick stone walls.

Seeing as you're in a field, why are you floating the floor?

Do you enjoy having your sub slightly in front and to the left, front and to the left?

It's questionable weather or not splaying the glass like that helps anything. I'm not really sure I would bother. Just throwing that into the mix. Razz

Got pics of the site and existing structure?

Posted: Tue Nov 25, 2008 4:07 am

Thanks Greener, it's my dream too Very Happy

The studio is not the barn, it's only part of the building, there's already a screed in place and next to the studio there'll be a play area so I want to isolate as much as possible from the rest of the building. Also, at the end of the building, with a separate entrance there will be my wife's practice (she's an osteopath) so again, I want to minimise leaks as much as possible... So I thought that floating the studio on an independent slab of concrete might be preferable. But maybe I'm wrong... again, I'm pretty much ignorant in all things acoustic!

Re. booth window, well I've seen it like that in all the Soho studios where I record so I thought, why not? Some of them even have three sheets of glass but I thought that'd be a bit overkill.

As for pix of the building, well, you asked...

This is the first floor, but it give a good idea of the inside space (it's 20 meters long X 10 meters wide X 10 meters high)

And that's the ground floor - can you see the studio, on the left of the pic?

Posted: Fri Nov 28, 2008 3:36 am

Another photo from the ground floor looking at the top beams, when there was no flooring on first floor, giving a good idea of the whole building - the studio will be on the left (the big thick wall on the plans is the one on the left of this photo). The pillars have been removed as the beams have been reinforced and as there will be other supporting pillars hidden behind a cosmetic partition wall (the 100mmx50mm RSG on the plan), and there will be a concrete slab over the flooring that has been since put on the first floor, visible on the pix above. The ceiling of the studio will be supported by the walls of it so will be completely independent from the ceiling/floor above it.

One thing I was wondering about is, is it necessary to put rockwool in the door or should it be all solid? Another thing I was wondering about is... what are the mistakes I made in my plan? Shocked

Thanks a bunch in advance for your help, I obviously need it Embarassed

Posted: Fri Nov 28, 2008 3:54 am

Hmm I'm not sure if you missed much more than putting you location in your profile but...
Click here for the "sticky" guidelines for this forum. Once you answer all of those something could happen. Razz

For the record I know nothing.

Posted: Fri Nov 28, 2008 4:07 am

TheFrenchVoice wrote:

Another thing I was wondering about is... what are the mistakes I made in my plan? :shock: Thanks a bunch in advance for your help, I obviously need it :oops:

Your building should be considered as one(1) in a two(2) leaf design. Your building exterior walls are solid block/concrete no?

You have Rods' book, read back over the mass/spring/mass area.

Posted: Fri Nov 28, 2008 4:09 am

That's very kind of you Greener, done! I think I've done everything asked for in the guidelines and have included as many details as possible in my post, but if I missed something, please admin people, show me the errors of my ways Shocked

And you might know nothing, but I know even less. So that's negative knowledge, if that's possible. Confused

Posted: Sat Nov 29, 2008 11:49 am

Space wrote:

Your building should be considered as one(1) in a two(2) leaf design. Your building exterior walls are solid block/concrete no?
You have Rods' book, read back over the mass/spring/mass area.

Hi Space, thanks so much for your input. The building's exterior walls are made of stones stacked up together, 60cm thick. Do you mean that on the exterior walls' side I should have: exterior walls, drywall fixed to it,100mm rockwool fixed to drywall, 5cm air - and then sitting on floating screed: 100mm rockwool, drywall, green glue, drywall? Re. mass/spring/mass area, well yes I've studied Rod's book but I don't really get it... I said I was ignorant and I was not lying!

Posted: Sun Nov 30, 2008 12:43 am

Pierre,

Let's try ascii art....

Your drawing shows;
0. Outside
1. Stone Wall
2. Air Gap
3. Gypsum
4. Insulation Filled Stud
5. Gypsum
6. Air Gap
7. Gypsum
8. Insulation Filled Stud
9. Gypsum
10. Room Space

This construction could be broken down one of two ways... either of which is not good from both an acoustical standpoint, AND a cost standpoint; You either have a Mass-Air-Mass-Air-Mass (Triple leaf model) or (I think more correctly) 5 leaf model.

You have to look at each space as an "air", e.g. the space between the studs/stud cavity – and each barrier as a "mass".

Your drawing shows the same principle on the interior wall assemblies.

The temptation is to think you need to put up as much mass/as many walls as you can. But, you really are over complicating it all, and thus can save yourself a TON of money and labor by simplifying it down to a simple Mass-Air-Mass model;

0. Outside
1. Stone Wall - "Mass"
2. Air Gap - "Air"
3. Insulation Filled Stud - "Air" (continued)
4. Gypsum -----\
5. Green Glue ---| - "Mass" (2 Layers of Gyp & GG are one Mass)
6. Gypsum -----/
7. Room Space

To optimize the transmission loss of your walls, you could increase the depth of the studs (15cm), and space them 61 cm (or whatever the EU standard is), OR use standard depth metal studs with resilient channel (RC) and space them 61 cm apart.

I've not worked with metal studs in a studio environment, so I don't know if using resilient channel (RC) would be of much benefit on the exterior wall or not. My guess is that on the exterior wall, RC would be of no additional benefit because of the extensive mass of that stone wall. However, I would hope someone here with more experience would chime in with some hard data. Otherwise, my understanding is that RC really does extend the low frequency TL.

If it were my money, I would do a cost comparison between standard metal studs with resilient channel and 15 cm wood studs.

BTW... the building really is beautiful... Just a shame you can't convince your wife to take your space for her practice and you take the rest of it for a studio. <sigh>

Posted: Sun Nov 30, 2008 4:13 pm

There is way too much thinking on the walls. Looking at IR 586 trying to get some reference of isolation with those walls, a fine construction would be:

Stone wall 60 cm
Metal stud ~ 7.5 cm thick
Insulation in between studs
Gypsum board.

This will give an STC in mid 60s, with greater than 35 dB transmission loss from 63 Hz up.

The limiting factor for sound isolation will be the openings in the walls and the roof.

Ref: NRC IR 586 fig 4, pdf page 9.

Andre

Posted: Mon Dec 01, 2008 9:32 pm

I don't even know why you should be worried with sound insulation apart from the typical separation between the CR and the TR since it seems you are in the middle of nowhere !

What you should be worried is the design of the studio itself and considering the size of the space I would suggest you hire someone to do this.

Posted: Tue Dec 02, 2008 12:10 pm

Thanks for taking the time to help me out here! Max and Avare, I hear you - I've amended the plan, is it what you meant? (I've also added bath traps at the ceilin corners in the tracking room and the booth)

Max, I've mentioned your suggestion to my wife, she would like a quiet word with you... Laughing

Andrebrito, you're right there's not much to worry about the noise coming from outside the house - but I need a proper sound insulation because next to the studio there's a playroom, and if clients are playing pool and enjoying themselves a bit loudly while their artist is recording I don't want that to be an issue. I do agree with you that the design of the studio is vital and I intend on using professional help for the acoustic treatment. I just thought that the collective expertise in this forum could help prevent me from making simple obvious mistakes. Simple and obvious to the experts of course, but way beyond my virtually inexistent competence!

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