Zoook Moto69 MonsterX1 240-Watts RMS or 2400 Watts PMPO Underseat 8-inch Car Subwoofer with Inbuilt Amplifier (Black) If you are limited in space or just looking to add some bass to your system, this kit is for you. The zoook monster x1 is a compact low profile powered subwoofer system that can be added under car seat, in tight spaces or just in your trunk. This subwoofer is powered, so no need for an external amplifier, it also comes with remote bass control. It's made by zoook, so you are getting quality made subwoofer that will last you years this 240 watt subwoofer is the perfect system for you if you are looking for that all in one system that is incredibly easy to install. Just wire the subwoofer to your battery, ground it, connect it to your head unit using rca cables (wiring kit not included). The monster x1 is an all in one solution to give you great sounding bass in your vehicle without taking up a ton of space. This sub enclosure is very slim so that it can easily fit under your seat. The amplifier is built in, so installation and wiring is easy and clean. We wanted to truly make installation a breeze so we designed this unit with the user in mind from start to finish. We added high level inputs so you don't need a remote wire from your receiver to trigger the unit on and off. The smart circuit will sense that an audio signal is present and turn on your radio and a signal is present. When you turn off your music signal the amplifier built into this subwoofer system will automatically turn itself off. Using the high level input is also the fastest and easiest way to install an aftermarket amp subwoofer combination since you do not have to remove the receiver. You simply use the high level input and wire it to one of your speakers. It has a level control for the volume, a subsonic filter to filter out the really low frequencies that the human ear can not hear. This also has a low pass crossover filter, phase control, and bass boost.