You can't find any amplifier for 12v HIGH POWER .
max power out from a 12v battery is near 20w(120w). :(
But you can convert 12v to 36v or more voltage from a voltage converter and then you can find 200w(1200w) or more power amplifiers which operating in 36v.
But if you don't like to make a voltage converter,you can make a dual 20w amplifier and connect it to dual voice coil subwoofer or use multiple small subwoofers.(it wont loss the deep bass.please check .you can undeunderst why are small subwoofer wont loss bass quality.)
It's not high power. But it will enough for you if you are have a real car.
Try this for a test.
I will tell you a best and cheap power amplifier circuit for a car subwoofer.
It is very very easy and tested .I never found any fault in that amplifier circuit.
Also the circuit is very easy to make.you can make it even without a pcb :D
The amplifier circuit made by TDA1516 IC.
Components :
Ic2=tda1516
C10= 10uf
C11= 104pf
C12=16v 1000uf
R18= 1k
D1=3v LED
The amplifier circuit made by TDA1516 IC.
Components :
Ic2=tda1516
C10= 10uf
C11= 104pf
C12=16v 1000uf
R18= 1k
D1=3v LED
