car aftermarket bass problem?

[Darko]

okay, i have a 06 rsx (non bose) and i have a kicker amp wired to my duel 12 inch sony xplode ported subwoofers. wired to a alpine a105, ipod is in the glove wired to a usb port in the back of the head unit. sometimes my bass will literally just stop hitting in the middle of a song, it can last for a half of a second or up to thirty seconds, i have checked and all wires are connected properly (all visible ones at least) . what could be wrong? the bass couldnt be bottoming out because it hits the same notes if i play the song again... its just in random spots. yesterday i took the head unit out and reconnected all the wires and it worked for aawhile but it happened again... what could be wrong? please help thanks.. ill take anyones two cents