First, for some background (lazy typist here) go to this thread
http://www.homer.com.au/phpBB2/viewtopi ... 86&start=0
and scroll down to the STC chart John posted on Mar 01 - look at the various wall constructions closely, then check the comments I made on Mar 17 as to WHY this is so.
Here are some general guidelines for soundproofing -
1. NEVER waste time/money/materials on construction methods that aren't proven to work, unless you have no life and just like to hurt yourself...
2. The best performance in a sound wall for the money, unless you can afford 3 foot thick concrete, will ALWAYS be a double-leaf wall with only ONE air space. Adding extra walls will usually make things WORSE, not better. (A "leaf" is however many layers of solid material that are layered together on one side of the frame. A standard, interior house partition with drywall on each side of 2x4's is a "double-leaf" wall.
3. This double leaf wall should almost NEVER have exactly the same construction on both sides - a wall transmits sound (bad) more efficiently at its RESONANT frequency. If both leaves of your wall are identical, then so will their resonant frequencies be identical. If that frequency is, say, 44 hZ, then that frequency will pass right through the wall with MUCH less attenuation than other frequencies. Not good.
4. For best performance, there should be no point where the inner and outer leaves of a wall have direct, hard contact with each other. This will allow sounds that impinge on the one leaf to directly vibrate the second leaf, and pfpfpfttt!!! Right on through... The way around this is separate frames, whether wood or steel studs. Drywall on the inside of the inner frame, and on the outside of the outer frame.
5. Things that improve Transmission Loss are: Mass of leaves (more is better, but DIFFERENT is better yet) - Distance between leaves (more is better - at normal wall thicknesses, even an extra inch can help) - Insulation - so far, it appears that 2.5 to 3 Pounds per Cubic Foot is the best overall density for in-wall insulation. This is why USG settled on 2.5 PCF for their Sound Attenuating Fire Blankets - see this link
http://www.usg.com/Design_Solutions/2_3 ... onperf.asp
It's getting close to when I have to go do less fun things, so I'll try to wrap this up for now -
I'd recommend you use steel 6" studs instead of wood if you can - the 20 ga ones can be used for load-bearing walls, and using 6" instead of 4" will improve the TL of your walls.
Put the paneling on ONLY one side of each frame - your goal is to have as much mass in only TWO leaves, placed as far apart as is practical (more air space) with at least 3-4" of either SAFB's (see above) or rockwool or mineral wool (same density) in between. More is generally better if you can afford it, and I believe it may work better (not positive on this) if it actually TOUCHES the inside wall panel - it should contribute to damping the panel, which would decrease the transmission.
On one leaf of the wall, replace the outer 5/8 wall board with 1/2" - on the OTHER leaf, replace the 3/4 MDF with "sound board" - typically 1/2" thick, kind of crumbly - goes by other names such as Homosote, Celotex, etc - it's the stuff those drop-in, 2x4 foot ceiling tiles are made of.
Either find a source locally (commercial insulation/drywall contractors, usually) of REAL acoustic caulk (about $3.50 per 1-QUART tube, or $7.50 each if you have to get it online) and caulk EVERYTHING as you go. You want all construction to be "boat" quality (would float indefinitely, hermetically sealed)
Home Depot carries the 1-quart caulk guns, but don't even slow down at their "wall of caulk" there's nothing there that will help you, except possibly their "drywall adhesive" which can be beaded on wood studs under the FIRST layer to even out irregularities and lessen the chance for rattles, plus it allows you to spread out the fasteners some without losing strength. I don't think it would be as beneficial on steel stud construction though.
One last thing, then I gotta run - check out the SAE site from top to bottom, it's the cheapest "consultant" you can find (free)
http://www.saecollege.de/reference_material/index.html
Click on EVERYTHING - by the time you finish, I guarantee you'll be answering questions for ME... Steve
Soooo, when a Musician dies, do they hear the white noise at the end of the tunnel??!? Hmmmm...