Subwoofer

I have a Jeep Wrangler and my Pyledriver sub had been exposed to some water last summer before I could get my soft top on.  Since then my sub has been making this ticking noise, is this a short?  Can a sub drain a battery within 12 hours?  When I went out to my car this morning it was dead and the ticking noise had increased to a rapid pace.

Is there such a thing as a waterproof sub?  Who makes them and how much are they?  Are they worth it?

unless the sub has a built-in amplifier, there's no way it could have drained the battery.  Even if it did have a built-in amp, as long as the amplifier had a proper remote turn-on connection, that wouldn't cause the battery to die.

There are speakers designed for installation in boats, but they are not "waterproof".  Just designed to be exposed to rain and occasional water splashes, not full immersion in water.  Here's a sampling of them:  http://www.crutchfield.com/cgi-bin/S-yIBzytvLeoX/ProdGroup.asp?c=10&s=0&g=79200&cc=01

Now about this ticking noise...does it come through the subwoofer?  Or is it just in the general area around the sub?  And does it only do it when the stereo is turned on? or is it a non-stop ticking that goes on even after you turn off the vehicle?   Does it vary with the stereo's volume?