In planning the upcoming conversion, one of the first issues I have to look at is insulation. While insulating an RV tends to be against heat loss and cold, more and more conversions nowadays incorporate some sort of soundproofing.
There are however differences in regard to RV’s that may make the use of it less desirable:
RV’s already have insulation applied and while styrofoam boards do little against noise, regular fiberglass batting does help against it.
It reduces vibration but not necessarily noise transmission.
Payload capacity of RV’s is often very limited and applying Dynamat adds almost 0.5 lb per square foot in additional weight. With a cargo van conversion and a reduced material application that would easily add another 100 lbs to the vehicle.
For many low budget conversions, cost may be prohibitive, unless you use cheaper products, such as Peel & Seal.
There are environmental consequences by introducing additional chemicals into a small confined place. Butyl and rubberized asphalt are chemical compounds.
RV’s tend to be primarily parked and not driven on a daily basis. This seriously limits any possible improvements in noise reduction.
For me personally, the choice is simple. I’m a thinker, not a listener; I hardly ever use my (car) radio or MP3-player. Noise reduction is important to me, but that can be achieved with other materials. Temperature control supersedes sound reduction by far. In the end it’s a personal choice, that should be based on your own requirements and daily use.
I’m not an expert in acoustics and these are just my personal views on a complicated issue.