For the most part I've been happy with the system in my boat. The biggest 'issue' to me is the subwoofer.
I have a Wet Sounds XXX V2 powered by a SD2 amp (~1250w). The sub is in the Wet Sounds recommended, dual slot loaded enclosure that I built. It sounds good but it just doesn't do what I want it to do. The biggest issue is that it is installed below the captain's helm and therefore is right in front of me since I drive most of the time.
I don't care much at all for upper sub bass and have always crossed my subs over around (or depending on the sub and environment, below) 55-60hz. That works for this system and blends in nicely, especially for everyday use and while we are riding. I lose a ton of output though when we park the boat and I want to really get on it.
I recently bumped the crossover up to around 70hz and it definitely got a lot louder but it doesn't sound all that great to me, especially from the captain's helm.
I had a good friend and well respected fabricator and enclosure designer model the subwoofer and enclosure and he said that for the first time in a long time, he actually agrees with the recommended enclosure. I've seen him do some really crazy things with enclosures and subs that you wouldn't expect to perform and have literally blown people away. He designed a ported enclosure for me for a Wet Sounds free air 10" that I built for a buddy's boat a couple weeks ago by looking at the TS and it sounded incredible.
He recommended that I look at some sort of EQ and spend some time with a RTA on my boat to dial the sub in. So I started looking a little.
I'd like something that I can quickly change presets, mostly for the sub depending on whether we are driving the boat or just chilling out (more SQ with a lower crossover setting and smoother bass) or it is parked and I want to really crank on it (more SPL).
Most of the processors seem like complete overkill for the boat since I am pretty happy using the 420SQ for the in boats and tower and I really only need to tune the sub. If I want something that I can easily switch presets on the fly, I'm probably stuck with something really nice though.
I mostly want a good EQ and flexible crossover. Here's what I'm considering at the moment:
Audison bit Ten D
Arc Audio PS8
I'd love to find a Rockford Symmetry EPX2 in great condition. I loved the one I had in my car I used to compete with in the mid to late 90's. All the new processors do more that the Symmetry but the nostalgia would be cool and it really is a great piece IMO.