Eclipse SW7124DVC defect?

I got some Eclipse SW7124dvc-t4 and some Eclipse SW7104dvc-t4s from my distributor on closeout and so they didn't have a warranty. I have just blown one of the 12's (sw7124dvc.t4) and I don't have a clue why. I have it in a box that is sealed 1.3 cubes, powering it is an eclipse 32240 2/1 ch. 400w rms.    I was playing it at moderate volume (mind you the sub was properly broken in and I am a professional installer) and the sucker just started smoking and giving the pleasant aroma of fully cooked voice coil.       This wouldn't bother me, except the fact that I had installed a sw104dvc.t4 10" inch in a friends vehicle, powering it with an amp that was 650watts max and the voice coil came unravelled (It doesn't have the odor of cooked coil) and they both make the same wire scraping aluminum sound.     Is this just coincidense or something worse?   I am pretty confident that it wasn't my error, I am not saying it wasn't but hey! I'm just trying to get some feedback before I even try to talk to Eclipse and have them hang up on me because I didn't purchase it from an authorized dealer.

I have had one customer who has smoked a new generation of the aluminum drivers. It however was warrantied by my distributor due to my being an authorized dealer. A sub is not going to go poof all on it's own. I hate to say it, especially to another installer, but this was your fault (inadvertently I am sure), in either how the system was set up or used. If the sub was going to fail, it would not give you the smoke and unravelling show. This is a case of the voicecoils being heated to the point that they are melting off of the former or the former itself has become melted and distorted it's shape. If memory serves correct with these generation of sub, then the former in them is aluminum and is thermally bonded to the aluminum cone for one really large heatsink. This coupled with the vented pole piece and perimeter venting of this speaker to me says that you breached the thermal barrier of the sub thus causing the sub to fail. No warranty though, tough pill to swallow. Should have taken the blue pill instead of the red one I guess. Top Secret, I can tell you but then my wife will kill me.

Thanks for your reply.   While I am surely willing to accept the fact that I probably made a mistake, this strikes me as strange. I haven't blown a subwoofer in 6 years unless it was totally on purpose.   Combined with the fact that the subs where 2 different sizes, in two different enclosures, two different cars, two different amps, and even the number of subs was different. The sw7104dvc (10) that blew out was in a dual 10" sealed sub enclosure with a vented partition even out any differences in the woofers as no two are exactly alike.   The 12" was alone in a strong sealed box with exactly 1.44 cubes. Now, I just spoke to my friend who had the 10's in his car when one blew was using a Eclipse   34230 (I believe.... it is the 2 ch./1100wm 4ohm unbridgeable big one) in the trunk of a Deville Concourse.    He only broke them in for about 3 hours (I know, 10 hrs. is proper) and then one blew. The 12 just started SMOKING wen I was in traffc with it up at a moderate level.   The 12" still stinks! The 10" not at all. Is there anything that might point towards the actuall cause either of these failues? The 12 was plugged into an eclipse 32340 (I doubt that is the right model number but it is a 650-800 watts max amp, bridged mono 2 ohm. I am putting more of these woofers into my car and I don't want this to happen again!    Thanks