Enclosure for Boat

[CleanSierra]

You've got right around 30" of port, with the tuning, 35" is suggested. You're damn close to what I'd give the sub for port are.

The above comment was my reasoning for suggesting sealed enclosure no cabin. Its why majority of boat installs are sealed it IB setups

[1852legend]

Jk13: Its an outboard jet boat. 18' long. Essentially just a fancy jonboat. Running big power is hard on boat batteries and alternators so I would like to avoid getting too carried away. I am very aware this is not the most ideal sub for my situation but I had it laying around from another project. Sounds like I need to bump the frequency a bit. That's the kind of info I need. I really only want to build this once. Thanks!

CleanSierra: By bumping Hz to 39.69 I was able to shrink the width back to 36". I now sit at 15Hx36Wx12D for the box and 13.5Hx2.5Wx20L for the port. This gives 33.75" of port. Question is, now that I changed the frequency, how much port would be optimum? I think I need to look further into the IB setup also. That just might be the way to go.

Thanks guys

[CleanSierra]

40" of port at that tune is suggested minimum.

[jk13]

Its an outboard jet boat. 18' long. Essentially just a fancy jonboat. Running big power is hard on boat batteries and alternators so I would like to avoid getting too carried away.

So no closed bow? No room under the helm? Make/model or pics?

I have an inboard Malibu ski boat with a Chevy 350 and a 50 amp alternator so I feel your pain in the available 12V power aspect. Multiple batteries and overnight charging on shore power is a common solution, especially with the "party cove" guys. Save one battery for starting and have a big bank of them for stereo on a Perko switch or heavy relay.

[1852legend]

Here are a few pics of the boat interior. My proposed box would sit behind the two seats facing forward (Pic 1). I do not see any other real options for sub placement. I have seen someone mount a free air sub in the storage box in front of the helm. (Pic 3). I was not impressed with the results.

Light and fast is the name of the game with these boats so hauling around a bank of batteries is not a real option unfortunately.

Thanks

[jk13]

Damn. So that's an OptiMax jet drive? I bet that boat has had some "oh shit" moments. Looks like it scoots pretty good.

I think you're on the right track with a ported box behind those seats. Maybe build it symmetrical so it can rotate and experiment with it either forward firing or down firing if possible. The depth of your woofer may not allow down firing though as that boat looks pretty shallow inside. Lots of guys like to fire woofers at the outside hull of the boat but you don't really have anything there to reflect off of. Just an angle up and out.

Not really a lot working in your favor on this one. Sub behind one seat and port behind the other may also work. Or even a parallel tuned 6th with the woofer in the middle facing sideways and a port by each seat. Gives you and your passenger the most effect at least.

[boom50cal]

Possibly think about a cap bank if you have space to snag it somewhere. One or two nice size batteries, and a decent size cap bank...maybe even a solar panel thrown in the mix to help it out somewhere. I'm assuming since the relative size of this boat, and your much more logic(polite way of saying your a bit older lol) perspective, that you will probably be sitting stationary and fishing for extended periods of time...maybe cap bank is too much. Just a pair of batteries and a solar panel.

[1852legend]

Jk13: Yep. 250XS. It gets a little sketchy at times!

Boom50cal: Hey now. Im only 27 and that boat has never even had a fishing pole in it!!! lol. Its just a toy for the weekends. I will look into the panel though. I have actually seen other guys use them. I always thought it was a waste of time but maybe they are worthwhile?

Thanks guys!