SIKCVC is right...if you want your subs to sound good, you need a good HU and amps...also make sure you get a amp that can run the sub, and dont trust what they say on the boxes...cause most of the times boxes are off.

I know alpine and rockford amps say their ratings are below what they are..if they say they are a 1000W RMS amp, its probably a 1090W RMS.

A good sound sub, is one that wont destort when turned up, also one that is tuned right, and one that is running at the right Watts and Voltage...also with a decent headunit