I have an exile audio ZLD MK2 zoned line driver/EQ for sale. It was in my boat when I purchased it and the previous owner had just got it before the sale. The ZLD MK2 is the newest one with all the improvements and it came out this year so it's the most recent Exile tech.
I can't tell you know nice it is to be able to control the output levels of your towers, cabin speakers, and sub separately. You'll never want to live without one once you've had one.
Retail price is $300 and I'll sell this one for $225 shipped.
Specs:
http://exileaudio.com/store/index.ph...er-preamp.html
Actual unit to the right of my steering wheel: