Originally Posted by sandrock
Kickers are rated at RMS. What you see as the designation on those amps, are the RMS watts
those amps are rated at rms IF you have the amount of current to supply the "rated" power at their rated voltage (some rate at 12 volts , while others rate at 14.4). starve the amp of current and you will never reach rated rms power.
keep in mind you have to figure in efficiency when you want to know how much current you amp wants to reach "rated" power.
since it'* a class d amp, efficiency is going to be about 80%, depending on design
1250/.80=1562.5 (its going to take 1564 watts for this amp to make 1250)
so what this tells us is that for your amp to produce its 1250 watts, you will need at least 108.5 amps of current and you have to have it running on 14.4 volts, which is supplied while the car is running.
dont go with a capacitor, get your current supply up man!