I assume that's the P3SD4-10, which calls for a .4 - 1.0 C.F. enclosure. You're probably not going to get that kind of air space in a box that fits within the cubby unless you cut the whole back of that panel out and let the box extend into the body cavity. Doable, but it's you call. Or, you could buy one of the enclosures that a couple of the guys on the forums make. As far as that sub and amp being okay for each other, you should be fine. The amp RMS at 250 is about 50 watts lower than the sub's RMS, but it will still play quite loudly. It's not the most efficient sub at 83db, but the two together should still massage your back, eventually ruin your hearing, and p!ss off the cars next to you if you wanted to. And if you can get a good deal and confirmation that there isn't anything wrong with them...

I'll put it this way. I have an Athena Technologies 8" subwoofer as part of my home theater setup. It has a built in 120 watt amp. It can get REALLY loud and shake everything on the walls. I think a 10" and 250 watts in your XJ should suffice. Unless you're just going for stupid loud and trying to impress the homies and make an annoyance of yourself.

 

Yes I've got enough now to have an idea of what I'm doing. I see myself sticking with a sealed for now but ill have to read into those links you tagged for sure.
I thought about that. My thought was ill just make it as big as I can without it being intrusive and then put foam in to compensate a little. I figure I'm no looking for necessarily competition quality so what I get is what I get..
And yeah I'm thinkin this will probaly be my max size as I hate being one of those "fill in the blank" on the road.
And cheers for confirming that matchup.

 

Hey MacGyver...where did you run your supply (for the amp) on the firewall? I'd like to keep it on the passanger's side but wanted your feedback...if you could do your install again where would you go?

I got a 97 and want an easy and clean run.

 

Here's how I did mine (your 97 should be the same as my 98):

A 40 amp fused 6 gauge wire going from the stud on the front of the underhood power distribution block (where all the relays are), to a separate aftermarket fuse panel I have mounted on the firewall just for aftermarket stuff (amp, lights, etc.).

From my fuse panel (a 30 amp fuse dedicated to the amp), I have an 8 guage wire routed along the main harness that is at the top of the firewall. I have this wire in it's own loom and zip-tied to the main harness. When I get to the driver's side, I have an area beneath the brake booster where I have drilled various holes and installed rubber grommets. My 8 gauge wire passes through one of those to the interior, goes along underneath the dash (zip-tied), and then goes under the center console.

From there, I have that wire coming out from under the passenger side of the console and going under the front part of the passenger seat (behind the front seat mounts) to the amp. I also have the remote turn-on lead from the head unit and the RCA signal wires routed under the console too, but I made sure the RCA's were the shielded type and kept them a few inches from any of the power wires. I get no electrical signal interference when listening to my music.

It would have been nice to keep it on the passenger side, but for me it's just too hard to work under there (I'm a stocky build 265 pound guy) and it's difficult to see what I'm doing. There is also the risk of accidentally drilling a hole through the heater core or AC evaporator coils or AC housing/drain area, which gets really expensive, really fast. There's just more room to work with on the drivers side and less chance of royally screwing something up. Also, if you have an aftermarket alarm with auxiliary outputs that would allow you to control your lights with your remote, most of the wires the alarm attaches to anyway are on that side, so it helps having it all together.

 

I have a 10" Infinity Basslink, it's powered and super easy to install. It is pretty big, but the connections on the back of the box make it easy to remove when you need more room (super nice to be able to do). The bass is enough to shake the windows pretty good, but it can be easily adjusted with a remote dial that I mounted to the side of my seat. I've had it for 6 months, and it works great. Some people claimed that it quit after 3 weeks, but I'm not complaining!