Part of DVC Blown?

I had a 15" sub with DVC. i had it hooked up to an amp for about 2 months and never had a problem until last night.  I was riding down the road, playing no louder than normal, or any different then normal and all of a sudden i lost all my bass.  No pop, no static, it acted as if the amp had got too hot and shut off, so i didnt freak. i pulled over and checked the amps temp, it wasnt hot at all, and had all power.  It was late so this morning i got up checked ALL connections from HU, from batt, to amp, to speaker.  ALL GOOD. I even pull the speaker out of the box. all good. well i unhook the speaker and check to see it only one side would work and only ONE set will work.  I thought i had it connected correctly, what would cause this to happen???  

Meter the subwoofer to ensure that it still has continuity through the coil. If both coils were hooked up and 1 coil shorted, then it may have caused the amp to go into protection. There is a chance that the coil is either melted or just open ( a break in the wire), in either case hopefully you have a warranty on the subwoofer. One possible problem that you may have is a heat issue in the coils. If the coils cannot cool themselves properly, this buildup of heat will cause the voicecoils / voicecoil former to melt (distort it's shape). End result is a blown speaker. If you are listening to your favorite music and a normal and sustained listening level this may just be the case. If you have clipped the signal going into the amplifier it may also be the root cause of the problem. There can be many causes for a failure , we need more informaton to find out what it might have been in order to help prevent it again. Anyways it sounds like a new sub is in your future.Top Secret, I can tell you but then my wife will kill me.

The amp didnt go into portection cause the light stayed on power and NOT protection. I bought the speaker second hand and dont have any warrenty.    The speaker doesnt sound blown because now that i only have the working side hooked up there is no distortion, but it does seem less powerfull. Is that the only difference when you go from DVC to single???

Like Fuseblower siad..it is and isn't blown...since its a Dual Voice Coil ( DVC ) it's like two speakers...you fubared one VC . so it soounds less powerful, etc. time to get it fixed or replaced....