ISKWEZM check this out please, need suggestions!

ok here's what i got.....most of it is old stuff, but i am told it is pretty decent, and cost big bucks when it was new...sounds pretty nice, but not enough bass anymore.....
headunit:Alpine CDA 7940
frontspeakers: old Alpine D Drive components ( i thought they were crap when i looked at em, but they sound better than my MB Quart components i have in my truck)
rear speakers: Boston Acoustics 5x7 Co AX ( dont remember the series, think i paid $169 for em)
subs: (2) Polk momo 8" in a custom sealed box built into spare tire well in my hatch
amprecision Power art series 606.2 six channel (powers whole system)
EQ: Precision Power DEQ-230 1/3 octave equalizer
1 1/2 farad power cap
the car also has some silly alrm in it that does everything except remote start

anyway, i am big on sound quality, and the system, as it is now, is really not bad....i listen mostly to heavy metal type stuff, so i dont need the bass to overpower everything else, but i like it loud! what do you think could be upgraded, and the older stuff i have in the car, i was told was pretty expensive when it was new. i have done internet searches for the amp and EQ, but couldnt find anything on them......any suggestions? not looking to spend a ridiculous amount of money or anything, but i am not unrealistic....

thanks for the input guys! i am pretty much gonna have to get a different box altogether though, as the air volume etc is correct for these 2 8"s.....also most likely another (additional) amp since even if i bridge this thing, it wont power the sub i would want to get if i upgrade ( jl audio 10 w 7)
i'll get pics up one of these days, its a real nice looking setup, amp, EQ and subs are mounted in a custom box, and they even saved some paint from when the car was painted to do up the faceplate for the box