I took out my under seat subwoofer because when I got my stereo installed the shop botched up the wiring and the sub does not work (I think it works, just not how they hooked it up) Anyways, when I pulled out the sub I unhooked the wiring harness and turned on the stereo (had the car in "ON" with the engine off). I head no difference as I plugged in and unplugged the sub so I figured it wasnt hooked up (although wires from the harness were spliced into other wires behind the stereo). I proceeded to cut the wiring harness (I was stupid though and didnt unplug it from the sub or turn off the car. Anywho, a few sparks flew, and the stereo/radar detector/defi's shut off and came back on. what the **** did I do? do you think I hurt anything? everything seems to be working fine now. Music comes out of all the speakers, the fader and ballance all work fine.

You probably blew a fuse, I believe there is a fuse for the sub in the harness so if you blew that one it wouldn't affect anything else. Check all your other fuses, if they are ok and everything works you got lucky.
Obviously you should not do that again.
FYI cutting the harness was a mistake, you should have unplugged it from both ends and kept it intact. The sub is now worthless unless you replace the harness and it's not cheap, around $75 or so from Subaru.

You probably blew a fuse, I believe there is a fuse for the sub in the harness so if you blew that one it wouldn't affect anything else. Check all your other fuses, if they are ok and everything works you got lucky.
Obviously you should not do that again.
FYI cutting the harness was a mistake, you should have unplugged it from both ends and kept it intact. The sub is now worthless unless you replace the harness and it's not cheap, around $75 or so from Subaru.

I couldnt undo the harness, the stereo shop that installed the stereo had the wires running everywhere through the other wirse and spliced at random places.

Ok, just bear that in mind if you go to sell the sub or want to use it again.
If the shop did wiring that lousy I don't suppose you'll be going back there any more.