Nsgarch I think we are agreeing and disagreeing.
I agree with your comment on mass and that's why I posted the comment about two doors. However, the space between them is some benefit too, especially if a sound panel is attached. (Hals_den said aesthetics were second to performance).
This from Wired Magazine
This from University of Massachusetts, Amherst, MA.
http://www.owenscorning.com/quietzone/products/products3.asp
Specification from Owens Corning including specification of attenuation with acoustical batting and sealing.
I agree with your comment about solid core 1-3/4 doors. In fact that's what I used in my home and what I suggested in my post.
I also contend two are better than one and better still would be if they did not line up with each other, but rather were staggered. However this is likely not possible in a residence where we have to work with what we have rather than constructing from scratch.
I agree with your comment on mass and that's why I posted the comment about two doors. However, the space between them is some benefit too, especially if a sound panel is attached. (Hals_den said aesthetics were second to performance).
This from Wired Magazine
How Sound Travels
Let's look at sound, and think about how it travels in order to better understand how to stop it or contain it. Sound is made up of energized pressure waves in the air that cause objects in its path (including our eardrums) to vibrate --objects like walls, floors, doors and ceilings. (Deep bass energy is the worst, as you may have noticed when you walk past a dance club or when a car with a booming one-note subwoofer passes by your home.)
Adding loosely packed fiberglass insulation in the wall cavities of interior walls further reduces the energy passing through, in effect making the air between the walls more lossy. Staggering the wall studs (see below) on each side prevents the bass from passing through because it has to move the studs and the wall, which is very hard to do.
This from University of Massachusetts, Amherst, MA.
Sound attenuation batts soak up sound and can improve the STC rating of a wall. We carefully installed 3-1/2 inch thick sound attenuation batts (Owens Corning http://www.owenscorning.com/ 1-800-438-7465) in all stud cavities after the resilient channel was fastened to the wall. We purchased batts that were sized for steel studs. These larger batts extend into and completely fill the hollow profile of the steel studs. Language on the package claims they can improve partition STC ratings by up to 10 decibels.
http://www.owenscorning.com/quietzone/products/products3.asp
Specification from Owens Corning including specification of attenuation with acoustical batting and sealing.
I agree with your comment about solid core 1-3/4 doors. In fact that's what I used in my home and what I suggested in my post.
I also contend two are better than one and better still would be if they did not line up with each other, but rather were staggered. However this is likely not possible in a residence where we have to work with what we have rather than constructing from scratch.