John Sayers' Recording Studio Design Forum

In the downstairs of our new house I have a raw space of 32' x 16' x 10' on a poured slab. The back wall and most of the side wall are 8" of poured concrete, buried in a hill side and the other two are a 2x4 inside wall and a 2x6 front outside wall.

I am going to build a room inside a room and my first question here is about wall construction for the best isolation.

Using John Sayer's 200mm inside out wall, which appears to have one leaf, looks fine against the solid concrete wall but my question is how should I finish the inside of the exterior 2x4 and 2x6 walls so I don't end up with a triple leaf?
Thanks

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Bill
www.billpillmore.com

you mean the exterior of the 2x4 and 2x6 walls? not the interior. you need mass - air - mass (2 leaf) so the exterior walls (concrete or other) need to be a single mass. so on the exterior finish as normal. on the inside of that wall against the outer sheathing add your mass - cement board, drywall, MDF, etc. drywall is cheapest. 2x or 3x 5/8" depending on your isolation needs. then your inner walls can be the inside-out construction without worrying that you're building a triple leaf.

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Glenn

John Sayer's 200mm inside out wall, which appears to have one leaf, looks fine against the solid concrete wall
-Not against the concrete wall. Leave a 100mm gap (filled with wool)

-is it standard to have two walls in a house where you live?
-What is normally on the this double walls? Dry wall on one or both side?
-is this just for a control room? Or two/three room built?

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inkspotproductions
www.bantamstudio.info

Glenn,
gotcha!

That means on the bottom of the upstairs floor joists (24"tall, which I am going to fill the whole cavity with fg insulation), I should not add dry wall but put the mass in my inside ceiling same as the walls?

If this is so, how much would I gain adding 2 layers of 5/8" dry wall to the sub floor above between the joists. At roughly 30x15x2 that would be 28 sheets of dry wall cut into strips plus green glue. Would it be worth the expense? Right above the studio is the master bedroom and master bath.

thanks

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Bill
www.billpillmore.com

Understand that.

Don't understand that

The long wall to the a-joining room (room with the chop saw) would normally have drywall on both sides but as you can see we aren't there yet.

The mix position will be centered at the window, there will be at least one iso booth and a closet/amp room at the back. Tracking and mixing in the same room.
I am trying to add a basic 2 dimensional sketchup but the file shows too big-598kb. Any ideas how to reduce it?

Thanks

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Bill
www.billpillmore.com

Here is the sketchup exported as a jpg.

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Bill
www.billpillmore.com

Then you would add an additional wall inset per Lilith envy to create your entie inner shell. Yes, adding the additional mass over head against the upstair floor will be worth while. How is the inner ceiling going tone supported? On the inner walls or suspended?

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Glenn

Ceiling will be supported on the inner walls but because of the weight and lack of head room the drywall will have to be added between the 2x6 ceiling beams.

Now that I have this worked out I can start designing the studio.
Thanks all

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Bill
www.billpillmore.com

I have almost finished adding two layers of 5/8" drywall to all ceiling and all the exterior walls and I am planing the room inside a room and it's an inside out room. I need help trying to figure out how to build the ship in a bottle.

I understand building the inside out walls on the floor and standing them up but how do I do the inside out ceiling when I am trying to maximize the ceiling height. I have not found any threads that do this. My only thought was to do them in 12' x 4' foot sections and jack them up some how and slide the walls under them. Any ideas.
Thanks

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Bill
www.billpillmore.com

I think the inside out ceiling is actually reducing your overall height by at least 2-3"+/-. Plus the added anxiety over how to do it. John has a thread/picture/drawing somewhere on this site where he shows smaller sections, but the followinf link is a fair representation of how he would design it:

viewtopic.php?f=1&t=13293&p=92158&hilit=inside+out+ceiling#p92158


But you could do something like this and make it easy on yourself with conventional and decoupled I might add,framing. You do have a 10 foot existing wall height correct?:

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

Thanks for the reply.
Interior dimensions after inside out walls and floor are 14'2"W x 30'6"L x 10'2"H.
Because of the awful room modes with a long room I was going to break it up - with a drum room and vocal room - tracking and mixing will be in one room.
Room mode calculators give me a good readings at 13'Wx 21'Lx 9'2" or 9'3"H.
Front of the room (mixing end) will have slightly splayed walls.
The home builder who is giving me lots of assistance wants to have the ceiling beams 2x6 running the 13' width rather than the 18' length.
I also have the beam at 16 feet and it would be easier to go under it with ceiling joist going across the width.
Just looking at room the room mode calculator then shows me I can put the beams across the room and put the drywall underneath. With ceiling treatment below that I should still be ok - I just hate to loose all that space over head.
New question-
How much insulation should I put in the floor joists- almost 3' of space? I was going to use fiberglass batts.
Thanks
Bill

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Bill
www.billpillmore.com

Maybe 6" on the upper floor and about the same on your new ceiling since the insulation is used in the enclosed part of a mass/air/mass system to damp the panels as a primary goal. There has been research done on filling the entire cavity with insulation, but the points gained aren't enough to justify the expense.

"The home builder who is giving me lots of assistance wants to have the ceiling beams 2x6 running the 13' width rather than the 18' length."


That's a good thing since 2X6 would only be recommended for the shorter span by people that do this for a living , the longer span would require either a beam to break up the span or most likely 2X12, the beam breaking up the span the better of the two options.


Don't lose any sleep over those room mode calculators, often it is best to do the math yourself, since it will be more accurate PLUS you learn first hand about what is going on inside a room.

But to be fair, if the height isn't dead on 10 feet to the interior side of the hard boundary, these mode calculators are useless, since this was part of the criteria used to establish the relations between width/length/height and volume of small rooms.


And if you alter the walls, splay them, it only complicates the process, moves the modes to a different frequency, so... get a ratio that works for your environment and move on to more important things...


AND...just to really mess you up...the hard boundaries are the place that measurements are taken from in order to establish a proper ratio, so if you have inside out wall assemblies and if you didn't measure from the actual hard panel (the sheetrock) your ratios are blown anyway

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

This is my idea of the ceiling of the room in side a room.
The 2x8's would be on 2' centers and a 2x4 frame (2'x7') with 2 layers of 5/8" drywall (2'x7') with green glue between, screwed on the top. Then this would be pushed up and nailed to the 2x8's.
This way I could nail a 2x8, put up the frames, and add the insulation as I go down the room.
Do you think this would work? Each frame with drywall would be about 95# and there would be 2 per row.

I want to thank John for this site and all the information and the other poster's experience and the help I am receiving. I really appreciate the experience.
Thanks
Bill

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Bill
www.billpillmore.com

I have seen this idea on another build here on the forum and nobody spoke up that it may be a problem so it looks like this is what we will do.
Next question is about the slab.
It is the only slab in the building and it is connected by rebar to the walls. The rooms above are connected to the concrete walls. Will I have enough isolation if I just glue the hardwood floor to the slab? If I build a small drum room in the back of the room will I need to isolate that floor.
This studio will be used for acoustic light rock bands and solo work and the drum room for isolation of an instrumentalist or small drum kit.
Thanks
Bill

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Bill
www.billpillmore.com

What is the frame doing if it is hard attached to the roof rafters? If you are just adding mass then just bulk up and hold it in place via cleats. The inner isolation space, to be effective needs to be decoupled. Same for the floor, you need to decouple it to avoid having the sound flank throughout the structure.

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Glenn