Nice, I have listened to both the M and MX series speakers, I found my ears prefer the improved fidelity from the M series esp... at higher volume, I have considered a subwoofer but after adding my M880's I don't need a subwoofer quite yet, mostly b/c I don't want to cut a 10"+ hole in my boat nor do I want to add a another amp to power it and when out side the boat at the local sandbar, you loose a bit of color as you say. I will admit I do miss those serious lows that only a subwoofer can offer. My JL HD amps can push the M series speakers to their recommended max RMS with ease, and the HD amps run at lower voltage input requirements, since they are power regulated amps with far better RMS that most amps. My house battery system uses 2 marine battery's. & about to add one more soon for a total of 3 batteries on the house, I use a inverter to power my 120 volt pump, for my tube's, take's seconds to fill most tubes over the standard 12 pumps another reason I want extra power on reserve since I don't use a ACR as its too much for the stators to keep up with multi batteries, I use shore power and allow my Dual Pro PS charger to recharge them. I just wanted to add some details, to give you a better understanding of my build.
updated: my HCLD's have much better reach over coaxial speakers for towers, and my REV10's do the job nicely.
I do like how Yamaha raised the speakers up higher in the rear seating area in the newer boats to be closer to our ears, for what is a better listening experience, that's my only down fall on my older boat, the speaker holes where already there so it was more efficient to make them bigger, rather than filling the hole and modify the seats to allow M880's up higher like the fronts are in my AR230.
btw I love lake Ray Roberts the water is so clean and blue, its just rare gem compared to most lakes here in the local DFW area. Do you happen to know of any good public spots to launch from besides the state park on the East side, I couldn't find a good spot on the West side of the lake.