Yikes. Now you are intimidating me! Hopefully, we'll be able to use a freestanding building. If i have to work within the confines of an existing space within a house, that is going to complicate things, but it sounds like you accomplished it. I get the ductwork damping. I assume the copper rods were for grounding, Bruce? And JPS- i'm gonna have to look into that. The lengths to which you went to literally seal the room were, i assume to keep unwanted noise out, as well as to 'soundproof' the room against sound emanating from the listening area/studio? And, for further rigidity/solidity of surfaces, acoustically?I had a few more obstacles than Mike. I built rooms within rooms in my basement. We had the forethought to have the ceiling raised to 13' before the house was completed because we knew we would lose ceiling heigth when the acoustial buildout was finished.
Because it was in my basement, I had to install HVAC "mufflers" in the main trunk off from the house. All the ductwork is lined with a dampening material as well.
The lights and 6 outlets use "house" current and the other 30? outlets are from my Equi=tech wall cabinet. I did have the electrical company run another line from the street and used custom 4ga run to the cabinet. Copper rods were placed in the ground about 50' as well.
Yes, the JPS cable is hard to work with, so what we did was crimp/solder gold spades with shrink tubing to the ends and just used the screws on the side of the duplex for connecting. We also had to use larger boxes with plenty of acoustical caulking to plug up the holes. I told the builders to think of these rooms as a submarine or aquarium. If water can leak through... so can sound. I used 27 cases of acoustical caulking to plug up all the holes. I also used about 24 cases of Green Glue. Not only did we use it between drywall sheets, it was also used between every single wood joint. All wood was engineered lumber and put together with screws... Do not use nails!
You will lose about 1/4th of the total volume of the room with bass trapping!
Nails, i guess, move, thus the screws?
On volume, I can't make any meaningful assessment til i get the room but it is good to know how much space i'll have to over-size. The best room i had was one long ago in an old brownstone in Brooklyn Heights. I had real plaster with heavy moldings, and wood lathing (not sure if there was horsehair, but it was like archeology to dig into the wall when we needed to do repairs). I was long, pretty wide, super high ceilings, and old, very wide plank wooden floors. Structurally, all the material in the room was from the late 1880's or 1890's, with updating for electrical, etc. I sealed all the windows with heavy stage curtain type material to block light, because the room doubled as a projection room. The room sounded fabulous with almost no treatment other than what comes with thick rugs and a modest amount of furniture, etc. That was 20 years ago, and my system has changed drastically.
Thank you for the insight Bruce. You and others here are helping me understand the tricks of the trade in a way that I haven't thought about at this depth. I will probably just hand the acoustic person, the electrician and the contractor a print-out of this thread!