Another wall thread 2 leaf

[1970428scj]

TL of Leaf 1 TL of Leaf 2 F0 (empty cavity) F0 (insulated cavity) F1
35.71 36.45 14.04 10.06 58.52


Leaf 1 is 1" stucco , 11/16 mdf, 2x6 , insulated ( 2x General Gypsum for stucco)

26" gap

Leaf 2 3x 5/8 General Gypsum I am planning to use green glue on this leaf.

What can I do to fully decouple the walls , Neoprene under and decoupler like a RSIC-DC04?
Thank you

[Gregwor]

11/16 mdf

Did they actually use MDF for sheathing? OSB or plywood is more likely. These all have different surface densities so I would confirm the material and then recalculate the isolation.

26" gap

That is eating into a LOT of space. Note, you will need the same surface density and gap for your ceiling as well.

Leaf 2 3x 5/8 General Gypsum I am planning to use green glue on this leaf.

You only need Green Glue between 2 of the layers, not between all 3.

What can I do to fully decouple the walls , Neoprene under and decoupler like a RSIC-DC04?

Well that opens up a few other issues. You COULD partially decouple the walls using a system like you mentioned. However, the slab is still connected to the outer leaf. Due to this, your isolation is limited to around what I believe is 60dB. You could split the slabs so that earth itself would be the only thing coupling the two rooms together. Otherwise, you have to get into the 6 figure price tag and actually float your inner room like Galaxy Studios has done.

What I'm getting at with my entire post here is that you need to make sure you don't go overboard on some sections of the room (like the 26" gap maybe?) while being limited at other sections of the room (like the connected slab).

Greg

[xSpace]

100`s of people right here, over a decade and a half that I have witnessed...have achieved quality audio recording room status.

Getting lost in the seduction of acoustics is common.

If you have a mass/air/mass design then you can also achieve your goal.

All the things Gregwor mentioned are pretty constant. I do not know what your isolation level goal is but it will be directly coupled to your budget.

[1970428scj]

11/16 mdf

Did they actually use MDF for sheathing? OSB or plywood is more likely. These all have different surface densities so I would confirm the material and then recalculate the isolation.

26" gap

That is eating into a LOT of space. Note, you will need the same surface density and gap for your ceiling as well.

Leaf 2 3x 5/8 General Gypsum I am planning to use green glue on this leaf.

You only need Green Glue between 2 of the layers, not between all 3.

What can I do to fully decouple the walls , Neoprene under and decoupler like a RSIC-DC04?

Well that opens up a few other issues. You COULD partially decouple the walls using a system like you mentioned. However, the slab is still connected to the outer leaf. Due to this, your isolation is limited to around what I believe is 60dB. You could split the slabs so that earth itself would be the only thing coupling the two rooms together. Otherwise, you have to get into the 6 figure price tag and actually float your inner room like Galaxy Studios has done.

What I'm getting at with my entire post here is that you need to make sure you don't go overboard on some sections of the room (like the 26" gap maybe?) while being limited at other sections of the room (like the connected slab).

Greg

Thank you for your reply.
I think giving more information of my Surrounding area might give you more direction as to what I’m trying to achieve. Please see attached photo.
I need to have as much isolation as possible,
With in reason,
I can see that a 26” gap eats in to my space a lot.
How can I get isolation with out the 26” gap,
And still be effective,
What is the most effective, way to isolate the slab?
It is a 6” slab with 2 ft deep stem wall.
Is it cheaper to cut around the stem wall and lay s new separate slab on grade?

What is the best way to decouple the walls from ceiling and floor.
Thank you

[xSpace]

The ceiling is a lot easier than the slab.

You simply never make a hard connection to the joist framing. Hard connections in light weight framing are where "flanking" exist and it is acoustically troublesome as it can reduce your anticipated isolation goal number to "whatever the existing structures current fstc is, give or take" .

Fstc being the field stc.

[1970428scj]

Thank you for the replies
Does this not work for isolation of the slab?

[Gregwor]

I'm sure it would work alright. I'd just be scared about the insulation getting too compressed. That's why a spring system could be more controlled.

Greg

[1970428scj]

I'm sure it would work alright. I'd just be scared about the insulation getting too compressed. That's why a spring system could be more controlled.

Greg

Greg
Thank again for all your info, that plan is from a pretty major design team that I’m sure you would know, guy has built and designed many great studios.

I’m trying to read between the lines as in these studio plans there are several things that are questionable.
RC all over this build, no real air gap between the buildings outside existing walls.

I have been in this studio and it is super nice and seals up.

What is my best design for my build
At this point I have a slab on grade,
I can decouple walls with neoprene,
I could do a floor like was pictured in the drawing?

How cost effective are spring jack type floors?
Would I need to do both the live room and control room?

My budget is more than $30k but not over $100k
I’m sure I’m gonna run out of money before the end.
Thank you for all your replies.

[1970428scj]

Here is another drawing from the same studio designer
This shows the main existing wall on the base slab with the same iso slab I pictured in the last post.
As you can see the interior walls is built right up against the existing wall.
A triple leaf design.

[Gregwor]

Thank again for all your info, that plan is from a pretty major design team that I’m sure you would know, guy has built and designed many great studios.

The designer would have worked with whatever requirements the owner had. Maybe they didn't need much isolation?

What is my best design for my build

It looks like you're quite far from anyone or anything so you're only needing to stop outside sounds from getting in and to have isolation between your rooms.

At this point I have a slab on grade,
I can decouple walls with neoprene,
I could do a floor like was pictured in the drawing?

I honestly think you'd be fine building your room like most people on the forum do by not worrying about your floor. Just build on your slab and achieve (hopefully) around 60dB of isolation.

How cost effective are spring jack type floors?
Would I need to do both the live room and control room?

You mean like this:

properly-floated-floor-spring02-SMALL2.jpg

My budget is more than $30k but not over $100k
I’m sure I’m gonna run out of money before the end.

Again, I think you should not worry about your floor. Spend your money on the other stuff. For example, I just got the quote to polish my control room and iso room floor (not my live room yet) and it's $9450 after GST. Budget gets eaten fast

Here is another drawing from the same studio designer
This shows the main existing wall on the base slab with the same iso slab I pictured in the last post.
As you can see the interior walls is built right up against the existing wall.
A triple leaf design.

Without seeing more of the picture I can't really comment on it, but if what you're suggesting is true, it is bizarre. Crazy to float a floor and then use RC and not a true room in a room. Also, from what I see in the picture, it blows my mind to float the floor and ultimately chew up a bunch of height in the control room, leaving only 8'4" of height.

Greg

[xSpace]

Thank you for the replies
Does this not work for isolation of the slab?

No, it does not work. Where did that come from?

Normal weight concrete weighs about 4000 lb. per cubic yard.

Microlite and 2 sheets of 1/2 inch sound board do not stand a chance against that weight.

[Gregwor]

No, it does not work. Where did that come from?

Normal weight concrete weighs about 4000 lb. per cubic yard.

Microlite and 2 sheets of 1/2 inch sound board do not stand a chance against that weight.

Exactly. The drum riser style design with insulation under thick sheathing has worked for some projects, but as I said before, the weight in that picture is too much for the material below it.

What studio is this?

Greg

[xSpace]

yes the drum riser damps specific frequencies but it does not "isolate".

[1970428scj]

yes the drum riser damps specific frequencies but it does not "isolate".

Hi thank you for your replies,
So my best bet is to do a 2 leaf system, neoprene on the base of leaf 2,
Use a decoupling hanger for the top of leaf 2 to keep it up right.
How large of an air gap do you think is enough for this space?
.
Thank you