The Zoom B1X Four takes everything that makes the B1 Four a versatile and powerful bass multi-effects unit and adds even more hands-on control with a built-in expression pedal. Ideal for bassists who want expressive real-time control over effects like volume, wah, pitch, or delay, the B1X Four is compact, feature-rich, and ready for both stage and studio use. With over 70 built-in effects, 9 classic amp/cab simulations, and the ability to chain up to five effects simultaneously, this unit gives you complete command over your tone. Beyond shaping your sound, the B1X Four encourages creative exploration. A 30-second looper lets you layer basslines, while 68 built-in drum patterns provide a solid rhythmic foundation for practice or solo performance. The intuitive interface features auto save, a preselect mode for silent patch changes, and an onboard tuner for quick tune-ups. Zoom’s Guitar Lab software expands your sonic toolkit even further, offering downloadable patches and custom effect editing, all accessible via the unit’s USB connection, which also supports power and firmware updates. Designed for portability and ease of integration, the B1X Four includes a standard ¼” instrument input, auxiliary input, and a stereo output that doubles as a headphone jack. It runs on 4 AA batteries (up to 18 hours), USB bus power, or an optional Zoom AD-16 adapter. Whether you're performing live, recording, or just practicing, the B1X Four gives you dynamic tonal control and real-time effect manipulation in one compact, pedalboard-friendly unit.