Sub=Stopped working...

This is the second time this has happened to me and I'm hoping its not the same problem as last time... I've got a MTX Thunder 5500 sub and a MTX Thunder 421D Amp. Last time I blew out my sub...Car toys said it was because when they installed it they didnt use the rights wires or something that go from the amp to the sub. Also there was something wrong with the internals of the amp so they send it off to get fixed. So they beef up the wires, replace my sub and everythings good right? Well...Everythings been good for a while now and I haven't cranked up the bass as much as I used to but this morning leaving school I decide I wanted to leave bumpin :rolleyes: So I throw in a cd with some heavy bass hits and as I'm waiting for the first hit it doesn't come...So I keep listening and absolutely nothing... :uhoh: So this is how I discovered I blew my sub last time...They also said my amp might just be underpowered for that sub but they said it should be good enough... Well... If its another blown sub then wtf... It was working 2 days ago and 2 days ago I was listening to some stuff with just some normal bass hits, nothing extravagant, then I threw in Modest Mouse for the past day or whatever so I turned my sub down so that it's barely there... And now I put in more bassy music and viola its gone! Could someone tell me if my amp. Does sudden cold weather cause anything wrong? When I got home I checked out the wire connections and it all seemed right but there was condensation on the amp and the sub box... Last night it got down to freezing and my whole car and everything was covered in ice and frost so could that have caused anything? I just hope I didn't blow another sub...This is actually the 2nd they've had to replace so I dont think they're happy with me...(the first time it was because I had the thunder 6000 *older and weaker* and the inner cone came unglued so they gave me a 5500) I just hope my warranty's still good.
SOOO sorry to digress and give you a long as story but all I really need to know is:
1. Is my sub to powerful for my amp? (should I beef up my amp)
2. Does the cold weather affect things like this/if so how to prevent it again?
3. Do you think my sub is blown?
I'm gonna drive it down to car toys tomorrow I think unless someone has some kinda answer that fixes it.

what amp are you using?
Cold weather really shouldn't affect things. My previous systems have always worked fine in freezing weather.
It could be a number of things.

I said it in the previous post but its an MTX Thunder 421 D amp.

Check and compare watts from amp to speaker, if you are only running one speaker and the amp watts exceeds speaker watts cranking the volume could blow the speaker, or speakers.

The cold should not make a diffrence, I live in upstate ny by cananda and my amp has no problems hitting, even in the dead of winter right when I turn my car on.

What is your hole set up?

is the sub you're using a DVC or SVC?

DVC SVC? I'm a newb I guess... But it ends up I just blew a few fuses...Hooray for not blowing my sub!

oh, thats good lol. But SVC = Single Voice Coil and DVC = Dual Voice Coil