Another update. Well beyond the 1k upgrade that this use to be. I have said that I was still not happy with the bass. I decided to go much further this time. My plan was to add another Polk 1040 mm on the Port side and build in hull sealed fiberglass speaker boxes for them both. I started with making the shape of the box working in the speaker hole with high density thick closed cell foam. I then filled any remaining gaps with spray foam. next was a good coating of epoxy. So far so good but working with the chopped strand mat in the speaker hold turned out to be so difficult and messy I abandoned that quickly as it would have end up with lots of air pockets and casing issues. Instead I let the epoxy cure and added more spray foam to the inside and outside of each box and another coating of epoxy with a brush. After curing I found a couple of spots where air still much leak so yet a bit more spray foam and then one last final very liberal coating of epoxy including pouring it from the top in a couple of spots. Last step was lining the inside of the boxes with MLV while the epoxy was still quite tacky. I went through half a gallon of epoxy and half a box of latex mechanics gloves in the process. Not what I originally planned, not pretty, and perhaps just a bit shy of optimum air volume but solid and sealed just the same.
I am now happy with the very hard hitting tight bass and no rattles. It sounds just as good at low volume as at high volume. I only got one photo of the enclosures because I did not want my phone anywhere near all that stickiness and I was always burning daylight to get it done. Given the amount of time and effort I highly recommend true free air subs over what I did if you are using the in hull locations.
I now have 2 pairs of mid cabin polk mm 651 powered from the jl amps, a pair polk mm 651 in the bow power from the head unit, a pair of polk mm 651 on the swim deck powered by the head unit, the factory tower tweets powered by the head unit, and two Polk 1040 mm subs power by bridged channels from the amps. The biggest difference I made in sound was adding the amps and adding speakers above the captain and co-captain cupholders.
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