soundproofing for urban people

I took a photo recently that shows the cross-section comparison of QuietRock 525 next to QuietRock 510. QuietRock 525 (on the left) is the 5/8" sound-dampening drywall from Quiet Solution, which seems to be partially comprised of concrete. QuietRock 510 (on the right) is the 1/2" sound-dampening drywall from Quiet Solution, and seems to be comprised of two pieces of 1/4" gypsum, fused together with a membrane of other materials in between them. As I stated in my previous post, I think the most effective use of QuietRock products is to glue them with Green Glue on top of another layer of gypsum that's already affixed to the wall studs. Better still, insert insulation between the studs before you put another layer of sheetrock over the existing wall. After a month of curing, I can say that the combination of QuietRock 510 and Green Glue was the most effective of anything I've tried to date.

A QuietRock story.... At the end of this post, I'm going to link yet another YouTube video. It's a TV story about some people who tried using QuietRock to replace some of the original walls in their townhome, which was shockingly un-soundproofed, and they were featured on a home-improvement show -- so it's a bit slicker than my own photos. First, here's my own story: I live in a building that was built in the 1950s, and the contractors used the thinnest, cheapest materials with no real soundproofing whatsoever. For example, the building had no insulation in the walls or ceiling, the walls are built of 2x4 studs with a single sheet of 1/2" gypsum nailed on each side, and the floors are merely thin planks of hardwood nailed directly on top of a plywood sheet, which is nailed right on top of the wooden joists. In brief, it seems that I had moved into a wooden tent. As a consequence--if you don't add any kind of soundproofing, noise travels easily from apa