With the new Groundpounder GPX amplifiers, Crunch defines a perfect new entry-level line for car audio beginners. Affordable, straightforward, with solid technology and excellent quality. The easy-to-use GPX 4-channel amplifier offers everything you would expect from high-end amplifiers: adjustable high and low pass filters, as well as switchable bass and treble boost. This model is also part of the new "All-Inclusive" bass packages from Crunch, which include an amplifier, bass reflex subwoofer box, cable kit, and installation accessories, providing everything needed to achieve great sound in your car without the hassle of searching for well-matched components.