boat system, need some advice

I am finishing up my boat install. It consists of 2 Infinity 4x75watt amps driving 8 Polk MMC650. As well, I have a 12in kicker L5 driven by a kicker KX600.1 amp (300watts @ 4ohms). The sub (and box) is from the original install last year; My problem is that after installing the second amp i lost enough room to put my sub in its original location (in front of the passengers seat and under the glove box is a rather large area). Now i think i am down to havening to buy a new box (which I'm not to excited for). My original box came with the sub and was vented. Now should i proceed with a new box being vented or not? I was under the impression vented boxes were loader and larger, verses smaller and better SQ. Keep in mind it is going on a boat and it needs to keep up with the 8 polks. Any advice is appreciated.

Vented boxes for that sub are bigger and louder but sealed boxes for that sub are not any better for sq. That’s assuming that the vented box is built correctly. It is exponentially easier to mess up a vented box design. Also your vented box needs to be designed for optimal performance in half space and not for free space or a generic predicted vehicle interior. In other words if the box you buy or have built for you is not designed for a boat you will be taking your chances on the out come.

A boat needs all the output it can get. Get the box purpose built for the application and ensure it is ported.

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