i have a the only thing in keeping from my old system is the alpine head unit. i ordered a audiopipe 1500.1 and a 100.4 and kicker ks 6.5s and 6x9s for the 100.4. i need input on the subs i was thinking 2 kicker l7 12s or 2 ia lethal injection 12s they will be in about 5 cubes before displacement. i want it to be as loud as possible dont care about sq thanks for the input in advance

Either would be a good buy but if your just looking for what may get you the loudest the give us a budget to work with.

Give us a budget.

With 1500 watts and 5 cu ft to work with, try a 15" Fi Btl or Bl, or a Sundown Z15. Some Incriminator Audio subs can be a good choices too.

If you want 2 12" sub, it will be more expensive than a single 15". Think about it.