The location is mostly irrelevant to the use of a Free-air or acoustic-suspension (small sealed enclosure) woofer. The two woofers are build differently and its not ideal to interchange their applications. A true FA woofer has more self-dampening to suite the large air space behind it. If you look at the T/S parameters of both the KM104 and KMF104, you see the difference in the numbers, especially the Q numbers. This tells us they act different, even though they are both 10 woofers with identical voice coil size and power handling.

What matters as to which one you would want to use, depends on the exact spot it will go and the surrounding structure. Refer back to the moomba pic I posted on page 1. You would not want to use the KMF woofer there, because the wall is only 3/4 of the way up. So that spot is not ideal for a KMF. What you would want to go with, is the KM10 AND put a small sealed or ported enclosure behind it. Thats whats been done on that boat thats pictured.

Not so sound like im picking on Moomba, here is a pic of a G23 that was the complete opposite. They had a perfect spot for a true FA woofer, but chose to use a non-FA Polk woofer. In that case, the fix is a little easier............install and proper FA woofer, which is whats pictured.

Port locker or under helm wont dictate the use of an FA or non-FA. It has to come down to how the woofer will/can actually be installed based on the listed requirements of each woofer.

As previously noted. Any time you close a woofer, regardless of its enclosure type, in an insulated locker, you reduce its perceived output.

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