Boss Audio 3-Way Electronic Crossover,

Product Overview
Get even better sound using the Boss Audio BX35 3-Way Electronic Crossover. Speakers reproduce sound based on high, low, or mid-range frequencies. This process is called the crossover effect and occurs because the vast majority of audio systems cannot cover the entire spectrum sufficiently to minimize sound distortion and maintain an appropriate frequency ratio. A lot of amplifiers have either a built-in "variable" crossover so that you can set the frequency at exact sound specifications or a "fixed" crossover. By connecting the BX35 to your amplifier, you will have total control you exactly how you want your bass to sound as well as your mid level and high level frequencies, giving you a pristine listening experience.

Highlights
Boss Audio BX35 3-Way Electronic Crossover
Front, rear and subwoofer inputs and outputs
Independent gain controls for each channel
Dual input selector
Bass boost on/off switch with frequency selector: 40Hz, 80Hz or 120Hz
Frequency multiplier (x1 or x5) on high pass output
Slope Rate: 12 db/octave
Signal-To-Noise ratio: >90 db
Remote On/Off power control
LED power indicator
Subwoofer phase and stereo/mono switches