Installation finished. Early thoughts, and preliminary sound measurements for comparison:
This project initially focused on hull liner replacement in the master stateroom. Then we decided to replace carpeting in the master, too. Then we decided to replace all carpeting. Then we decided to add carpet underlayment for sound abatement -- thanks to the thread here.
Then, once we saw how well the new hull liner looked, and how good the installer was, we decided to replace the hull liner in the guest stateroom and behind the hanging lockers, etc.
IOW, requirements creep, but it was really only a choice of doing it all now and enjoying it ourselves for longer, or doing it all later.
The installation went well. We chose the Soundown with 1/2" premium foam and the 2-lbs/Sq.Ft. mass layer. My original thought was that the boat wouldn't notice the extra weight. Almost blew it, with that decision. The two engine room hatches weigh approximately 35-lbs each, they're large enough to be awkward, and the underlayment would have added about 38-lbs each. Woof!
As it turned out, the installer was able to wrap the mass layer of the Soundown on the hatches... and then free-float that hatch carpeting/pad in the "trough" (?) created by the surrounding carpet/Soundown on the main part of the cabin sole. The result is that it looks like a wrapped hatch, I can move the carpet/pad in one step, then lift the hatch itself. The hatch pulls are underneath the carpet/pad... so normally completely invisible. We'll see if that works, but so far the hatch carpet/pad hasn't moved. I may decide to add some double sided hook-and-loop in between, if it becomes necessary... but so far, so good.
Here are the raw sound measurement numbers; I haven't done any real analysis yet:
Test # before/after =
center of pre-selected dB-C range setting: Average dB-C, Minimum, Maximum = description
1 = 60: 61, 55, 66 = saloon, AC, 1 portable fan
1 = 60: 58, 52, 67 = -3, -3, +1 dB-C
2 = 70: 72, 67, 75 = master, AC, 2 portable fans
2 = 70: 63, 58, 69 = -9, -9, -6 dB-C (?? seems spurious ??)
3 = 70: 75, 71, 78 = saloon, genset, AC, 1 portable fan
3 = 70: 72, 69, 76 = -3, -2, -2 dB-C
4 = 70: 74, 72, 76 = saloon, genset, 1 portable fan
4 = 70: 73, 69, 75 = -1, -3, -1 dB-C
5 = 70: 68, 63, 76 = master, genset, 2 portable fans
5 = 70: 62, LO*, 69 = -6, -3?, -7 dB-C (?? seems spurious ??)
6 = 90: 91, 82, 97 = engines underway, 2215 RPMs, saloon, genset, AC, 1 portable fan
6 = 90: 90, 83, 96 = -1, +1, -1 dB-C
7 = 90: 94, 85, 100 = engines underway, 2415 RPMs, saloon, genset, AC, 1 portable fan
7 = 90: 93, 84, 98 = -1, -1, -2 dB-C
8 = 80: 75, LO, 80 = engines in slip, 1205 RPMs, saloon, genset, AC, 1 portable fan
8 = 80: 75, 71, 80 = NC, +1?, NC dB-C
9 = 80: 78, LO, 84 = engines in slip, idle (625/605 RPMs, saloon, genset, AC, 1 portable fan)
9 = 80: 78, LO, 83 = NC, NC, -1 dB-C
* “LO” means lower than the lower limit of the pre-selected 20 dB-C range
-Chris