New theater started today

Hey man!


Congrats on the HT underway.


I would think twice about the double walls, though -- that is, if you mean

double drywall.


I have been doing ALOT of reading lately about room acoustics, and

the "stiffer" your walls and boundries the more low-frequency problems

you will have. You can read through the "White Papers" at www.harmon.com to get more detailed information on the theory behind

it.


The author is Dr. Floyd Toole, formerly head of the acoustics reasearch

department of Canada's world renowned National Research Centre (NRC).

He is VERY knowledgeable and has done alot of research in this area. The

papers are easy to follow and will get you thinking.


Companies like Paradigm & Psb, to name a few, are where they are today

because of the NRC. In fact, the MLSSA system that pioneered FFT

measurements was born of the NRC. The top loudspeaker and audio

engineering companies all over the world flock to the NRC to use their

research facilities, and to pick the brains of their researchers -- and they

pay top dollar for it. Here we have the benefit of doing it for free !


Enjoy !!


-Sporty

Thanks for the link!


The double I mean is 2 individual standing walls with a .5 inch gap between them.


Each will be fully insulated and drywalled like this:

|* |*| .... |=drywall *=insulated studs .=ignore


main wall of theater will be drywalled on each side, and then the outer wall will only be drywalled on the outside. This will make an independent room (room inside a room). I also have planed for a storage room to one side and a HT equipment and video storage room to the other, with the other 2 sides being foundation walls.


Then the same is done with the ceiling like this:

.| | | | ... this is upper floor joists

. | | | ...this is the ceiling rafters that sit on inner shell walls only


This doesn't show that the joists and rafters are actually inset to each other. The only contact that the upper floor and joists will have with the theater ceiling is the insulation that will fill the openings.


I am still working out the entrance to the room, but will final that in the next few days. I have a 4 foot hall going in to the room, from the side and near the back.


Will post more as I progress!!

Sporty,


One thing that I have found by reading the experts is that they often disagree on things. The issue of double drywall is one area but here at least both sides have stated why.



Regurgitated (hopefully without errors):

It seems double drywall is used to improve isolation while single drywall is used to improve room dynamics. So which to choose depends on which trade-off you want.


Double drywall works as an isolator as there are two layers of double thickness and an over all heavier mass. This helps keep the energy in the room.


Single drywall flexes like a drum thus absorbing some of the room harmonics like a base trap.


I have not decided which I'm going to use yet. Certainly, most people here have chosen double layer. Perhaps the information from Dr. Toole will help. But, I can't read it as your link leads to an empty site.

Oh well, 4 days later and no drywall is up. Planned to put some up today, but then I realized that the main water line for the house was going to need to be removed.


It just happens to be in the way of 3 recessed lites. I had planned to replace it, through a different section of the house this spring when I started the moving of my utilities room and make that line a outside faucet, but now it has to be removed.


So hopefully plumber by 9am and dry to go up by 2pm.


I did some more looking into sound control, and had read on a couple of different places that double walls a great, but if you put a sheet of drywall on the inside of the double, you degrade the rating!!


So my new configuration will be as follows:


|**..**| |=drywall *=insulated 2x4 studs ..=spacing


Duaned, for the lumber, insulation, electrical, change heat runs, drywall, and misc. just under 1500.00 Plus tomorrows plumber (but he owes me a lot more than I owe him). The amount that was added for doing the stand alone room guesstimate estimate of 500.00.


I would definitely do it again, just the 300 dollars spent on the insulation for the joist (r30) would be worth doing in the entire house!! Sent my wife upstairs when done putting it in and had her walk and march and stomp around. Barely heard her when she stomped. 30 plus year old house with silent floors, ye ha!!


Will post some pictures I hope soon.