Stereo Width
Definition
The perceived breadth of the stereo image in a mix. Narrow mixes sound focused and mono-compatible; wide mixes create expansive space but may suffer phase cancellation issues in mono playback.
In Simple Terms
How wide your mix sounds—from narrow and focused to spread-out and expansive. Too narrow and the mix sounds small; too wide and it falls apart on mono speakers like phones.
In Practice
A stereo width processor on a synthesizer pad expands the side content, making the pad feel like it extends beyond the speakers while keeping centered elements tight and focused.