Under seat sub install
 

Have a 4 ch 50w per ch Alpine pushing 4 Polk's from the stock head Would like to instal Kenwood under seat 150W under seat powered woofer. Can I run this off the amp or do I need to go to the head and battery. Is thi setup to much drain on the battery. Thanks

Can u be more specific? Model of sub. If its a powered sub with the amp built in it needs rca cables from head unit. Power and ground. If your using a line converter you can get y adapters to add additional outputs to the powered sub. As far as battery drain.... i think you mean strain on the electrical system. Battery drain occurs when the vehicles accessories are on and the engine is off. As far as strain. 2 small amps wont affect the stock electrical system much. So no.