I'm working with a home theater contractor and discussing the construction of my dedicated room. In the past, I have used the hat channel, sheet rock, and green glue, and have been very pleased with the results. However, this contractor is advocating for the use of dynill, and says that for a very similar cost, could achieve superior sound isolation. I've only really seen the green glue and hat channel discussed primarily here, so I was curious of the opinions on dynill and if that would truly give me better results.

do a search on MLV mass loaded vinyl.

The general consensus over the years that I've been reading this forum is that substituting a layer of MLV under the the drywall instead of a double layers of drywall on channel does have value, but is not better and costs a lot more per sq ft than adding an extra layer of DW and GG. I have significant doubts about the superior results claim, ask for the independent data.

Just thinking about it logically, MLV adds some damped mass, but doesn't do much to decouple the drywall from the framing, since the drywall fasteners will just penetrate the MLV (of course there will be a bit less coupling between the drywall and the framing because the two aren't in direct contact).


At the same time, cheaper clips seem like they also couple the drywall fairly robustly to the framing, and yet they apparently provide huge soundproofing benefits that are only marginally less good than higher end clips that decouple more.


So intuition only goes so far. There's lots of data out there on various modes of wall construction, but not a lot on MLV, as best I can tell.