Hello! I am going to buy a new subwoofer to my car. The problem is I dont know if I need to buy one 15" subwoofer or two 12" subwoofers? Each 12" got 1500RMS 3000w max. The 15" got 3000RMS and 12000w max. I will ofcourse choose a fitting amplifier depending on wich subwoofer i buy.