New Room in New Zealand - Walls, STC, Drums questions

[JohnGardner]

Hi there,

John designed this for me in the design forum and it rocks.

I can really only afford one stud wall for the live room.

Please find following my plan for the live room wall construction.

My questions are:

(1) Does this look OK, (will it work!!) What I am trying to do is utilize the existing exterior wall for some STC value without touching it.

(2) Any ideas of the STC of this wall. I plan to record acoustic drums and eletric gtars and want to keep the neighbours happy who are about 10metres (32feet) away.

(3) I keep reading about "resilent channels". Do I need one between the stud and first sheet of wall board on the inside wall. Can you buy resilent channels if so what do they look like?

(4) Stupid question but how do you keep the rockwool from falling into the airgap?

(5) I will build another wall exacly the same as this inside wall between the control room giving me a double wall here. Is that the idea?

Thanks

JohnG

[giles117]

Well it is not the optimum thing to do.

BUT!!!!!!

I had to do just that for my outer shell walls as I took a house and converted it into a studio and did not have the time to knock out all the plaster and plaster boards and garbage that is associated when you remove an inside wall of a 1920's house to renovate it.

I am pleased to announce that when drums are being recorded, I can go outside, stand 10' away and barely hear anything coming through. Now let me elaborate. I covered all the windows on the inside with particle board (3/4)" Painted black. Then I built the inner wall as you are questioning. My Inner walls are pf cpurse multiple layers of Drywall with 3" AFB (rockwool) in side them. All I can say is people outside never know I am working. As I said it is not optimum, but it works good enuff for my purposes. I dont even hear mr 10 12" woofers in his truck when cutting vocals in the live room either which is quite nice.

The neighbors next door live 15' away from this house as this is in a urban area. Highland Park, MI (right inside of detroit)

Hope that helps.

My best guess is I am getting about between 30-40db of reduction at about 5 feet from the house. (Just a poor mans using his ear test.... standing at the property line which is 5 feet from the side of the house )

Rock wool is pretty resilient it tends to stay together pretty well, but you can place nails or screws along the back edge of your studs to help keep it in position (the cheap way)

And of course I did build the PROPER double wall betwen my live room and CR and that is what you should do. I am sure if I had not it would be a nightmare in the CR when cutting drums. LOL