Zoom B1X FOUR Bass Multi-Effects Processor with Built-In Expression Pedal

Zoom B1X FOUR: A Bass Rig with an Expression Pedal On Board

The Zoom B1X FOUR is a bass multi-effects processor with a built-in expression pedal, and that treadle is the one reason to pick it over the B1 FOUR. A foot on the pedal rides volume for swells, opens a wah or filter sweep, or morphs an effect's depth while both hands keep playing the line. Behind the pedal sit the same tools as its sibling: more than 60 effects, nine bass amp models, and up to five effects chained in any order across 50 patches. For a bassist who wants to shape dynamics live, the expression pedal turns a fixed patch into a moving performance.

Low-End Tones That Move Under Your Foot

Nine amp models span vintage tube warmth to modern grind, and the effect set adds compression, octave, envelope filters, overdrive, chorus, and delay voiced to keep a bass's fundamental solid. Assign the expression pedal to an effect parameter and a static patch becomes expressive, sweeping a filter or swelling a synth in real time. Up to five effects run at once and store across 50 memory locations for footswitch recall. That combination covers a full set of bass tones from one compact box.

Build Grooves and Practice Smarter

A 30-second looper with unlimited overdub lets a player stack a bassline and jam over it, while 68 rhythm patterns supply a beat to lock into. The expression pedal adds live dynamics to those loops, so a practice idea already sounds like a performance. A chromatic tuner keeps the low strings in pitch without a separate pedal. For the bedroom player, it is a self-contained way to write, practice, and improve.

From Practice Room to Stage and Studio

Over USB the B1X FOUR is an audio interface, recording bass into a computer with its effects and expression moves printed in. Zoom Guitar Lab manages patches, backs them up, and expands the effect library. Four AA batteries or USB bus power keep it running from rehearsal to a fly-in gig with no amp to haul. The expression pedal, the amp models, and that portability make it a complete bass rig in a box you can carry in one hand.