hey can you help
 

i left the lights on so the battery died... i jumped the car.. accidently touched the leads together so it died, jumped it again and was sure NOT to touch them together this time.. the car started, the sub was really weak, its a 400w rms powered by 400w rms amp both jbl. the front and rear speakers were fine.. i thought maybe my battery was just weak but i let the car run for 10 minutes without the stereo on and this morning the sub is still so WEAK.. the amp lights are on the sub is working i thought a fuse could have blown but..

why is it so quiet? i had the same sub before and it blew completely and even filled my car with smoke but they replaced it and i turned the gain down a bit
and now its just so quiet?

any ideas would be appreciated

its about half as loud as it was 1 day ago

Unplug one of the RCAs from the amp and see if it keeps playing. If it does, plug it back in and unplug the other one and see if it keeps playing.

Since you killed the battery, the deck has probably re-set all its setting back to factory defaults. If you had bass boost eq or gain setup in the deck, you'll have to re-do it again.