Enclosure for Boat

[1852legend]

Looking for enclosure suggestions for alpine type x 12. This sub is going in an "open" boat. I'm not positive if I am tuning to the optimum frequency for my application or not. Through research I have found that Alpines "optimum enclosure specs" are anything but optimum so I am hoping you guys can give me some advice.

All kinds of music listened to, but primarily electronic and rap.

Current power is:

1000 peak

505 RMS at 4 Ohms

Will upgrade amp by summer to 1000 RMS or more.

Here is what I have came up with. Any suggestions are much appreciated. This is my first stab at a ported box.

Box dimensions: 15Hx36Wx12D Depth is max. Open to change width. Like to stick with height.

port dimensions: 13.5Hx2.25W 28" Length (Physical port length: 25")

Wood thickness: .75

Sub displacement: .194

Common port walls: 3

Any help would be much appreciated. I have already learned quite a bit from this forum. Thanks!!!

[1852legend]

bump

[CleanSierra]

If it were me, I would probably just do a sealed enclosure on a boat.

[Soccerballzs]

Use water proof board and water proof glue! How many subs?

[CleanSierra]

What tuning frequency were you wanting or what tuning have you calculated with that port. I haven't run any of the numbers yet.

Around 35 Hz I assume

[1852legend]

175db: Since it is in a noisy environment, (running at 60 mph) I figured I wanted the most loudness possible. In my experience, sealed offers tighter, better sq, but you lose overall volume. My logic may be flawed however. The boat is garage kept, only used in fair weather, and no kids so moisture is not a major concern if that's why you suggested sealed.

Soccerballz: Just one sub. Not much spare room.

175db: You are real close with your guess. 33.96 hz is what that port gives. It was suggested to me to go with 35 hz due to the open air environment, but due to my music taste I figured 34 might be a good compromise. I am definitely open to suggestions in this area if anyone has a different opinion.

Thanks for trying to help guys. I'm happy to hear what you more experienced people have to say.

[1852legend]

I ran my numbers in torres, but couldn't post a screenshot or I would have saved you guys the hassle of running the numbers yourselves.

[CleanSierra]

My username is CleanSierra, not 175db hahaha, it made me laugh though. I haven't done any boat setups though, I'm only thinking sealed or Infinite Baffle would be the way to go in one. A single 12" sub isn't going to have CRAZY amounts I'd output, regardless of enclosure. A sealed box will have a nice flat response in the right sized enclosure and you can always make it a little on the big side, as well as stuff it with polyfill.

You can definitely do ported to though, and that tuning sounds like a good idea to me. It will be a little louder than the sealed option, especially around tuning. I would be sure to give the sub plenty of port area with the enclosure you decide to go with. You're going to want to coat the box to keep it weatherproof. You may also consider fiberglass so you can make the most out of a specific area of where you place the sub.

[1852legend]

Hahaha! Sorry, long day.

I just found a fatal flaw in my calculations. 12" deep gave me plenty of depth for the sub, but I didn't consider the fact that the port is going to extend into the box to about the center, essentially leaving me too shallow. Magnet will be hitting the port wall. I'm gonna go wider in order to both shorten the port, and get it further from center/sub mounting position.

New specs:

Box 15Hx38Wx12D

Port 13.5Hx2.25Wx24L Physical port length 21"

Port area per ft 12.95 in²

Net volume 2.35 ft³

Tuning frequency 34.28 hz

I'm a little concerned about my current port area per foot. In another post I found 14 in² per cubic ftworked well for others (Same sub). I can't seem to find any concrete info on port area however.

Any opinions?

^Thanks

[jk13]

What type of "open boat" exactly?

Ported but tuned much higher usually works well in boats--45Hz or so. No cabin gain like a car so unless you run a lot of power on a big sub you won't get that heavy bottom end, especially if the goal is sound at speed.