I am running my JL 12"W6 in a sealed box that sits in the back of my hundai excell. It basses good and the car rattles. I am only running one voice coil at 300 watts at the present moment but now I have a 600 watt amp and tried to run both the voice coils paralel at 2 or so ohms( I don't know the calculations for ohms) and it did not sound as good. It sounded sloppy and diustorted the bass. Are the JL's designed to run a ported or bandpass box when they run both voice coils. Should I run my voice coils in series at 8 or so ohms My amp is a MEI DA4450 and runs 600W max when bridged mono. How can I meashure the ohms it puts out when bridged.