glossary
Mono bass means keeping the lowest frequencies centered and phase-stable.
Mono bass usually means summing or narrowing the lowest frequencies so kick, bass, and sub energy sit in the center. It does not mean the entire mix has to be mono.
The goal is a low end that survives club systems, earbuds, vinyl-style constraints, and mono playback without losing weight.
Stereo widening, chorus, unaligned layers, or phasey samples can make low frequencies unstable. When those lows are summed to mono, parts of the bass may drop or change tone.
The problem is easiest to miss on wide monitors and easiest to catch with correlation, mono checks, and focused low-end listening.
Use a crossover, mid-side EQ, or bass mono control to center only the lowest range. Leave upper harmonics wider when they help the bass read on smaller speakers.
Meter Core helps watch stereo behavior and loudness while you decide how much width the low end can keep.