x2thats happend to my l5 b4 i got my type-x. i was palying it loud and it just died; as if it was nto even connected. took it back and they told me it was blown, so i got my money back and bought somethnig else
Edit, just read your last post...
i had somethnig similar also occur to my type x. it turned out that the wires inside the box going from the sub to the metal connecters on the box got to ohot and melted, repalced with bigger wire and never had problem since then.