My Subs went out, i have no idea why, need help, i cant stand it Options

[quicknstyle]

ok, i had bought 2 12 in mtx subs in the box, with a 600w amp with all the wiring from my friend, he installed it since he knows how. it worked fine for a long time about maybe 6 or 7 months. then about last week i was driving somewhere and everything was fine. got out, did what i needed to do, but when i got back in for the drive home, i had no more bass! i have no idea why! im not exactly good at all the electrical and wiring stuff, especially when it came to this so i need some help. i check back there and there were 2 wires disconnected one from the amp, and one connected to the box, i reconnected them but it still has no power. but im pretty sure my amp is still working cuz its still charging my door speakers cuz the bass on those is so high that if i turn up the bass from the deck, it distorts really bad. so maybe someone can help me by showing my some troubleshooting tips that i can possibly do myself. i cant stand this. no music sounds good in my car. PLEASE!!!!