A bass synth (or bass synthesizer) is a type of synthesizer designed specifically for creating bass sounds, such as deep, punchy, or resonant low-end tones that provide the foundation of many musical genres. Bass synths are typically capable of producing a wide range of bass timbres, from smooth and rounded sub-bass frequencies to gritty, aggressive, or distorted bass lines. They often include features and sound design options that allow musicians to shape the bass character to suit various genres like funk, EDM, hip-hop, rock, and more.

These synthesizers usually have specific oscillators and filters optimized for generating and shaping low frequencies. Common controls include waveform selection, envelope shaping, filter cutoff, and resonance, which enable the user to create dynamic and powerful bass tones. Popular bass synths include classic models like the Roland TB-303, which helped define the acid house genre, and modern analog and digital options like the Moog Sub Phatty or the Novation Bass Station II. Bass synths are essential for producers seeking to craft distinctive and impactful low-end sounds in their tracks.