12" sub recommendations

A little background: I currently have a Sony Xplod 12" sub that the previous owner of my boat had installed. It is running on a Sony Xplod 1200w amp. the sub is installed on the drivers side kick panel area in a custom made box. The box is sealed and is give or take 2.5 cu ft inside volume.

My main questions are:

Can I just upgrade my sub and keep it on the same amp and box? If so, what is a good recommendation for that cu ft volume sealed? (JL, Sundown, Kicker, etc)

I would prefer to keep the box just because it does fit perfectly in the kick panel area, is this to much volume for a sealed enclosure? Should I port it somehow, and if so what is the best way to go about that without destroying the box?

I do realize this is broad, and a lot of questions and scenarios but looking for some info on what some of y'all would do (David, please chime in accordingly) if in my shoes. Let me know if any more info is needed. Thanks in advance!

Originally Posted by iShredSAN

A little background: I currently have a Sony Xplod 12" sub that the previous owner of my boat had installed. It is running on a Sony Xplod 1200w amp. the sub is installed on the drivers side kick panel area in a custom made box. The box is sealed and is give or take 2.5 cu ft inside volume.

My main questions are:

Can I just upgrade my sub and keep it on the same amp and box? If so, what is a good recommendation for that cu ft volume sealed? (JL, Sundown, Kicker, etc)

I would prefer to keep the box just because it does fit perfectly in the kick panel area, is this to much volume for a sealed enclosure? Should I port it somehow, and if so what is the best way to go about that without destroying the box?

I do realize this is broad, and a lot of questions and scenarios but looking for some info on what some of y'all would do (David, please chime in accordingly) if in my shoes. Let me know if any more info is needed. Thanks in advance!

Conner,
You probably do not want to try a retro port into an existing sealed enclosure. It's a little too complicated for that.
I also am conflicted about using an existing custom box without really investigating it's construction. Any imperfection causing the enclosure to leak can spell an early demise for your sub, not to mention bad performance along the way. Cheap terminal cup, caulked wire with no terminal cup, untreated MDF, no elevation off the sole, etc.
I wouldn't necessarily try to match the Sony amplifier rms rating with a woofer because I seriously doubt the amplifier delivers that much power real world. Sony, while certainly capable of anything technical wise, probably isn't putting their best foot forward in the Xplod series, if you know what I mean.
Most 12-inch air suspension subs will work well in a sealed 1.25 cu.ft. internal enclosure which would be about 1.85 cu.ft. external. Some 12-inch subs are designed for a little less. A bass-reflex 12-inch enclosure might require about 2.85 cu.ft. external.
I would resolve the enclosure issue and have a very accurate assessment of the maximum available external displacement BEFORE selecting a particular sub driver.
When it comes time to select a sub driver, it's helpful to know what your bass performance priorities are. Type of music. Musicality/deep extension/linearity. Maximum peak output. Maximum capacity for abuse. There is no magic pill where one driver does all things. Some people like tight bass. Some like fat bass because it gives the impression of more output. There is no wrong answer. Just personal preference.

Thanks David! Your stereo knowledge amazes me. As for the box, it is treated MDF, sealed on the inside and glassed on the outside (then covered in carpet to match boat interior). The terminal cup is decent and sealed as well. I agree with the Sony amp statement and at this point would like to keep using it due funding or lack there of.

I am unsure as to what you mean by external displacement but the box internal measurements when calculated gave me 2.5 cubic ft. I listen to all types of music and have rev 10s on the tower and nice in boats as well so really just needing some better bass due to just having this single older sub. So assuming I left the current box (sealed) and want a nice clean deep bass, is it possible to give a recommendation?

I believe the sony only puts out around 400 rms or so. The box is way too big for a sealed 12. You could run a 4" aero port if you have room to make it simple. With that power I would probably run a JL 12 w3 or the Wet Sounds xs-12

Originally Posted by iShredSAN

Thanks David! Your stereo knowledge amazes me. As for the box, it is treated MDF, sealed on the inside and glassed on the outside (then covered in carpet to match boat interior). The terminal cup is decent and sealed as well. I agree with the Sony amp statement and at this point would like to keep using it due funding or lack there of.

I am unsure as to what you mean by external displacement but the box internal measurements when calculated gave me 2.5 cubic ft. I listen to all types of music and have rev 10s on the tower and nice in boats as well so really just needing some better bass due to just having this single older sub. So assuming I left the current box (sealed) and want a nice clean deep bass, is it possible to give a recommendation?

So based on the power number that Brad supplied, I also agree with using either the JL Audio 12W3 or Wetsounds XS-12. Both are balanced designs. I wouldn't want to go with a heavier mass sub or larger voice coil with that amount of power. However, either sub will allow you to grow a little if you ever do replace the Sony amplifier.

Displacement: A 12X12X12 internal enclosure is one cubic foot. With 0.75" wall that would be 13.5X13.5X13.5 resulting in 1.4 cubic feet external. The 'external' is what fits the boat and where you should begin before selecting the driver, if you are starting with a fresh box.
You can always reduce the box, but with 2.5 cu.ft. at your disposal think about a JL Audio 13W3. Surface area rules. The less that woofer has to move to create output the better it sounds. Plus, you wouldn't think that you can hear a difference in a sub with a slightly lower resonance but it does sound different. No matter how much a purist, I don't know anyone that doesn't enjoy just a little extra bump down in the deepest zone.

Awesome, thanks for the input fellas. I was wrong on the cubic feet, it is closer to 2 rather than 2.5. If i were to add a 4" aero port, is there any place in particular it needs be mounted? Can it be mounted on the top eventhough the sub is facing out of the front side? Also, is adding the port going to make a noticeable difference?

Originally Posted by iShredSAN

Awesome, thanks for the input fellas. I was wrong on the cubic feet, it is closer to 2 rather than 2.5. If i were to add a 4" aero port, is there any place in particular it needs be mounted? Can it be mounted on the top eventhough the sub is facing out of the front side? Also, is adding the port going to make a noticeable difference?

Oh sure, you could port the existing enclosure and a port will definitely make an output difference. But keep in mind there is a giant difference between a tuned port and just a tube in the box. You would have to go through a number of enclosure and port conversions with programs that may not be especially accurate.
A port on top means that water can get in but not out. In a tight under helm cavity you would ideally want the woofer and port orientation on the same plane. You also have the option of placing a significant portion of the port on the outside of the enclosure.