Zoom B1X Four Bass Multi Effects Processor with Expression Pedal Speaker Frequency response 30Hz 20kHz 602567643647 Frequency response 30Hz 20kHz 2 dedicated output streams for headphone monitoring The Zoom B1 FOUR and B1X FOUR take your low end to new heights with over 70 effects and amp models editing and managing effects and patches● 68 built in rhythm patterns which can be used in conjunction with the Looper● 50 memory locations for storing user created patches● Auto Save function for automatic saving of all patch parameters● PRESELECT function allows silent patch selection while the current patch remains operational● Onboard chromatic tuner● Input jack accepts standard mono bass guitar cable (both active and passive instruments supported)● Auxiliary input jack for connection of personal music players● Output jack for connection to amp or headphones● Lightweight and small enough to fit in your gig bag● Easily integrated into any existing pedal board● Runs on 4 AA batteries