John Sayers' Recording Studio Design Forum Archive

Select "Construction", then "Walls and ceilings", this is the proverbial "a picture is worth a thousand words".

Reading is only part of this business...you have to pay attention to the pictures, the ones that have the mass on the outside of the frame, the type you were discussing.

But to be fair, if you missed it, you moved through it far too quickly...

Pretty straight forward, really.

xSpace wrote:Select "Construction", then "Walls and ceilings", this is the proverbial "a picture is worth a thousand words".

Reading is only part of this business...you have to pay attention to the pictures, the ones that have the mass on the outside of the frame, the type you were discussing.

But to be fair, if you missed it, you moved through it far too quickly...

Pretty straight forward, really.

I'll Have a look at it, I was more looking for an explanation on what exactly it is and why it works, and how to apply it in my situation.
My goal with this room is to do it without any building aother than the room itself.

The concept is simple: Build the inner-leaf wall with the frame facing the room and the drywall facing the other way, towards the outer-leaf wall: "inside-out": The main reasons you'd do that is to save a bit of space, and to make it easier to install treatment, since you can do it between the studs.

If you are building in an unfinished garage or basement, where you only have a single leaf at present, then you probably can build nothing but the new inner-leaf room. But if you are starting with a finished room, then your chances are not so good...

- Stuart -

Agreed.

You, drummerdude, will not find a "explanation", no more than you will get an explanation to why is the interior of a room sheathed. After the pictures are thrown out there for all to view, and you have at least a little understanding of what it is you are looking at in the first place, it should be clear.

Like, you asked "why it works. Well, we covered that...the reason it works on the out side of a framed assembly is the same reason it works on the interior side of the same framed assembly. It is a barrier of mass, and that is where you start to isolate sound.

What Johns inside out wall does is to take the mass on the outside, has the insulation on the air space of the framing area, then he uses slats at whatever specifications the room requires to get some hard surface back, add some treatment and diffuse the room a bit.

I get it now, I appreciate all the replies. I thought the name meant something more complicated maybe, because the studs and insulation are not doing very much in terms of tl.

What is the best way to do air exchange, I just need to exchange the air with the basement air, nothing else. I plan on using a safe n sound door, so my weak link is the air ducts. I had planned on using ductboard placed in the ducts as explained in the acoustic sciences videos, but I still need help with getting it through the wall without defeating the mass I will be installing. Again, thanks for all the help.

http://johnlsayers.com/Recmanual/Titles/Acoustics4.htm

Look under "Air Conditioning"

BriHar wrote:http://johnlsayers.com/Recmanual/Titles/Acoustics4.htm

Look under "Air Conditioning"

I have read that already, it doesn't really address my issue. my issue being I have to have the ducts come through the drywall and not sacrifice the transmission loss, I am assuming the ducts have a lower transmission loss than the drywall, I know everything needs to be sealed, but there is no point in 2 layers of 5/8 type x, if the ductwork voids that. should I create a bulkhead, which will have the triple leaf just in that area, but will force the sound to still have to go through 2 layers of drywall? Thanks agian.

Enough with the triple leaf...it does not exist in your HVAC.

Everyone here will be guessing, myself included, since we have not the first picture or draft to view, but again the process is simple...

You have to build baffles of mass to allow the air in and out and you have to decouple these baffles one from the other in order to maintain the broken path.

Your ducts do not have a lower TL, what they present are a challenge. The challenge is to build the baffles and the chutes required to isolate the sound in the air space.

Do you have a design, any kind of floor plan that we can "view"?

xSpace wrote:Enough with the triple leaf...it does not exist in your HVAC.

Everyone here will be guessing, myself included, since we have not the first picture or draft to view, but again the process is simple...

You have to build baffles of mass to allow the air in and out and you have to decouple these baffles one from the other in order to maintain the broken path.

Your ducts do not have a lower TL, what they present are a challenge. The challenge is to build the baffles and the chutes required to isolate the sound in the air space.

Do you have a design, any kind of floor plan that we can "view"?

I'll try to put a floor plan together. I meant the triple leaf because if I built a bulkhead over the drywall, and then drywalled that bulkhead, the bulkhead would be a triple leaf.

how can I do the baffles?

I meant the triple leaf because if I built a bulkhead over the drywall, and then drywalled that bulkhead, the bulkhead would be a triple leaf.

Not if you did it right!

how can I do the baffles?

Search the forum for "HVAC" and "silencer". There are many examples of how people have done theirs. Basically just a sealed wooden box with a "maze" of baffles inside. The dimensions are important, though.

- Stuart -

Adding to what Stuart said, if I were you drummerdude, I would lose the term "triple leaf" from my acoustical lexicon.

It is not the worst thing you can do...it derives from poor design and little examination of the goal that is in front of you.

I guess, in gamblers speech, it is the trifecta of doing everything wrong.