Thinking of adding a sub?
I got an 04 XLV that I was thinking of adding a subwoofer to I am already running an amp for my 6 6.5" in cabin speakers and a kicker 450 watt amp for my tower speakers and two batteries wired in parralel will the boat charging system handle a third amp to run a sub?
To be... or not to be... A bass machine.
Think the Op needs to answer his own question on the battery situation. Everything in this thread is for the most part is speculative academics without knowing model numbers and such. What really needs to be asked is, "How hard are you going to run your system. " And how long do you want it to play... As an example, I was on a boat this weekend with a class AB tower amp powering 4 speakers, class D cabin / sub amp powering 6 cabins and a sub...
He had two stock batteries and played for almost 4 hours at moderate volumes without needing to charge the batteries. That figure can go way up or way down depending on the music volume and even types of music being played. In your particular situation - adding a subwoofer is by definition going to become a major user of battery current. With that said, It's a great idea to add a sub for one primary reason: You'll gain almost a full octave of musical information that your not presently hearing in your current configuration. You don't have to be a bass head to enjoy the bottom end musical extension that a subwoofer will add.
In all light heartedness, you need to step in front of the mirror and ask your self, "Do I want to be play harder, longer and louder..." than this scenario mentioned above. If the answer is yes, start investing in charging and bigger battery banks and a mean looking subwoofer. Several of the guys in this forum are in that category. Several are not.