This post may contain affiliate links.
If you remember back to last summer, I embarked on a two part RV Soundproofing project where I installed three different kinds of materials in our RV trying to tame the noises we hear while we drive. The results from the first two parts were underwhelming, and we concluded we needed to do something about our RV’s cab-over area. That happens in this video… PART THREE!
The materials we used in the first videos were from Second Skin Audio. And even though the results from those first efforts weren’t as effective as I had hoped, the folks at Second Skin liked the videos, and offered to provide the materials to complete this third part. The good news though is that since we’re dealing with data and measurements, and things anyone else could duplicate, we don’t have to worry that their sponsorship altered the experiment.
So How Did It Go?
Knowing that a lot of time (and RV mods) had happened between the first videos and this one, I decided it didn’t make sense to compare things to those previous measurements. So we headed out to our test mile of interstate, and took a “before” reading with the sound level app on my phone. That result was 73.0 decibels – which was actually louder than where we had left things in the previous videos. I knew I hadn’t tried any sound amplification projects in the RV, so I think we can chalk that up to a slightly different RV, measured with a different phone, on a day with very different weather.
Then, it was time to tear things out so I could install the sound deadening materials. But when I got everything torn out, I realized what a truly large space it was that I was dealing with.
And once I realized I had this much space available, I thought I could make better use of it than by simply putting it back as it was. But building something different would have spelled trouble for the experiment. So I decided to steer the testing in a different direction, and try to measure the noise levels of JUST the cab and the sound deadening materials. We went for a ride with the forehead bare – just raw fiberglass on the inside. And then we went for a ride with just the sound insulation installed, no cabinetry. For both of these tests, we moved the microphone up a bit to try to capture as much of the forehead sound as possible.
For our pre-test, measuring just the empty forehead area, we got a reading of 73.3 decibels. This was louder than the first measurement, but only by 0.3 decibels. I think this points to the limitations of on-the-road testing with consumer equipmet. It was a different day, different weather, different wind, etc. Qualitatively, though, the blank forehead really did sound like an open window.
Then we installed our two sound deadening materials.
- First, we installed a layer of Second Skin Damplifier, directly against the fiberglass.
- Then we installed a one-inch layer of Second Skin’s Mega Zorbe Pro, on top of the Damplifier.
When we went back out on the road to test the forehead again, we got a reading of 69.5 decibels. I do feel like this is valid with respect to the 73.3, as we took both of those measurements on the same day in basically the same weather, just 7 hours and 30 minutes apart. Even if you discount this somewhat to account for variables which may have changed, a difference of 3.8 decibels is very significant in my book.
One nice thing about these materials, and the Mega Zorbe Pro in particular, is that they enhanced the thermal insulation in the cab-over area as well. The Mega Zorbe material has an R value of 4.16 per inch. That forehead area can get quite hot in the summer and cold in the winter, so that’s a nice bonus to all of this.
Overall, I’m happy with the results on the acoustic and thermal fronts. I’m even more happy with the large amount of space I was able to gain as a result of this mod. I’ll post up how I did that conversion in my next video.
Any questions, ask away in the comments below!