i need help so any suggestions will be appreciated... k so here is my story.. when i turn my system up  my subs cut out.. good bass when the volume is low but fucks up when i turn it up(pardon me French) at first i thought it was a power issue so had the battery checked its got 750 cold cracking amps  with 12.5 volts and my alteranotrs charging capacitor is good  subs r... so maybe the amp(dude at the shop thinks its fine) but like i said its good down low and yesterday it was fine back to its old self then today it took a shit again... could it be a the deck..
have the same setup for about 2 years with no problem