There are basically two types of sound "control". The first is a product to absorb sound, as in a recording studio or a movie theater, where you are trying to minimise echo/reverb. You can cover every inch of your wall in eggcrate if you want, but it wont do much to eliminate sound from the outside. Foam is typically light and airy, fairly good at insulating, bad at BLOCKING sound.
To block sound, you need mass, think concrete basement, bunker, cave, etc., You can scream to the top of your lungs and sound does not get out through the earth or concrete walls. Ironically, they are very good insulators as well and can act as heat sinks to help manage temperature, but are obviously not usable in any way for an RV application.
The best "lightweight" product you are going to find for use as a sound deadener or blocker is a mass laminated vinyl product (MLV). Everyone knows "Dynamat" and while they are more of a marketing company and certainly not the top of the game, The idea is sound, no pun intended. A good quality MLV that you can actually see some results from, is going to be about one pound per square foot.
On the foam, you want a closed cell foam for inside the wall use. Phenolic foam has an excellent R-value (upto R-7 per inch) but can be expensive and somewhat difficult to find (not carried in home improvement stores)
Liquid or semi-liquid sound and heat control products such as Spectrum's Sound Sludge and LIzard Skin (heat and sound) are also viable options.
To block sound, you need mass, think concrete basement, bunker, cave, etc., You can scream to the top of your lungs and sound does not get out through the earth or concrete walls. Ironically, they are very good insulators as well and can act as heat sinks to help manage temperature, but are obviously not usable in any way for an RV application.
The best "lightweight" product you are going to find for use as a sound deadener or blocker is a mass laminated vinyl product (MLV). Everyone knows "Dynamat" and while they are more of a marketing company and certainly not the top of the game, The idea is sound, no pun intended. A good quality MLV that you can actually see some results from, is going to be about one pound per square foot.
On the foam, you want a closed cell foam for inside the wall use. Phenolic foam has an excellent R-value (upto R-7 per inch) but can be expensive and somewhat difficult to find (not carried in home improvement stores)
Liquid or semi-liquid sound and heat control products such as Spectrum's Sound Sludge and LIzard Skin (heat and sound) are also viable options.