Lack of Power

I have two alpine type r 12 with an alpine pdx 1.1000 amp and an alpine deck. But when I turn the volume around 18-20 the subs cut off. Should I get a new battery or a capacitor? Also, what are good speakers to buy for a 2004 grand cherokee?

check your gains because my pdx 100.4 will cut out around the same volume if the gains are set even a hair to high.

wow, they just cut off ? I am thinking of getting acouple of PDX amps for my Accord, it will be fun retuning everything.

i think there is a problem with channel 3 on mine which is why it is doing that but dbr said he might not be able to fix it because he has no clue on how to open it. lol