Direct radiating a 12" sub in the port walk through question.

[House324]

I have a sport nautique 200 with factory (3 pair of Polk MM650) in boat speakers,1 pair of rev10's tower speakers powered by JL mhd600 and mhd750 respectively. I replaced the old factory 10" Polk free air sub mounted in the port side of the walk-through (observer storage compartment) and replaced it with a with a loaded jl audio 12TW1-2 ported sub box powered by a mhd750 (overkill). I removed all the carpet off of the JL box and sprayed it with bed liner to weather proof it. I mounted the new enclosure so that it directly radiates out of the existing walk through speaker opening. I glued speaker cloth inside the factory trim ring to maintain a clean look.

My question is..Does it matter that the box is ported, and that the port is enclosed inside the locker? Will there be any loss/interference with having the port radiating inside the locker and the speaker radiating directly outside the compartment?

And a big thanks to all the help from contributors like Odin, DavidAnalog, MLA and others...you guys are a huge resource to these boards.

[David Analog]

Yes, it really matters. The bottom octave of bass is created almost exclusively by the port. Over that frequency range, the woofer is heavily damped by the ported enclosure, hardly moves, and produces very little in acoustic output. In this particular application, since the port output is concealed within the compartment and sealed off, you should build a new and compact sealed enclosure and convert to air suspension. It should sound better.