Stacking multiple 'stereo' sources hard left and right creates Big Mono — width without real stereo

Big Mono occurs when many instruments (keyboards, effects devices, synths with pseudo-stereo outputs) are all panned hard left and right simultaneously. Instead of a wide, deep stereo image, the result is everything piled on the extreme left and extreme right, producing a sound that is wide but has no real stereo separation — effectively a mono signal spread to the edges. Dave Pensado identified the three ‘sacred territories’ in a mix — extreme left, center, and extreme right — that require careful justification for placement. The solution: discard the chorused side of pseudo-stereo sources, keep the dry side, and create custom stereo with pitch shifting or delay — then pan to intermediate positions (10:00 and 2:00, or narrow pairs like 9:00 and 10:30) for localization without Big Mono.

Examples

A mix with four synths, all panned hard left and hard right, sounds cluttered at the edges and empty in the middle — Big Mono. Fix: pan synth 1 to 10 o’clock / 2 o’clock, synth 2 to 9 o’clock / 3 o’clock, each at different depths. Result: width without pile-up.

Assessment

Given a mix with six pseudo-stereo synth layers all hard-panned L/R, describe the procedure to diagnose and fix Big Mono, including what you do with each stereo source and where you would re-pan them.