Components that count for this question are as follows:
Amp: JBL GTO-751ez
Sub/Box: Sundown SA-8v2 dual 4 ohm in 1.4 cubic feet net @ 33hz
I know the enclosure's too big, especially for the power. That's why I've been GENTLE with it. I've got a lot of amp gain to go UP before it's 'tuned' (a long, long way)-- I tuned it up using the JBL setup cd and then proceeded to crank it way the hell down (to about 1/3rd of where the setup CD put it) because I didn't need any more to get full excursion. Max (tuned) volume at the Head unit is 30 (out of 50). I only rarely break 20...never played full tilt (can't stand the highs anymore past 25, rockfords are loud as hell!)
Anyway, the sub cut out today on the way home. Dual 4 ohm sub is now reading 2.3 ohms and 3.5 ohms on the respective coils. I pulled the sub out of the box, and the coils look fine, as do the tinsels and spider so I'm hesitant to think I did any mechanical damage from the big box, but there's no burnt coil smell either. Actually smells like MDF sawdust and new woofer still. Only a few months old. Checked my connections (first thing I did, actually) and everything's good there.
Anyone have any input?
EDIT: Just measured the coils again. Dead-on 4.7 ohms per coil now. Perfect match. Either my DMM sucks (probably) or I'm a retard.