3 00W Underseat Compact Subwoofer – In Phase Car Audio USW300. The key thing about the In Phase USW 300 is the performance, the little active woofer really packs a punch, the bass response is amazing, you really do get SUB Bass from it. Its extremely responsive so the music has a completely different sound once added to the car. Many people think about changing speakers in you car, my advice is just add the USW 300 and you will think you have new life in your car! Enjoy its an awesome product. This underseat subwoofer comes with it’s own wiring and amplifier. Please do not use any other kit. 5″ x 8″ Aluminium Speaker. Die Cast Aluminium construction. Variable Subwoofer crossover 40-150hz. Speaker Frequency range 40-150hz. High Level speaker input. Max Power consumption 10Amp. W 280mm x H 200mm x D 75mm.