Guitar dual-cab & multi-mic phase — why two cabs cancel low end in mono
Two guitar cabs (or two mics on one cab) can sound huge in headphones and thin, hollow, or scooped when the bus hits mono. That’s usually phase — not “need more distortion.”
Download PHIXER free PHIXER hub
PHIXER is free stereo phase-repair (VST3/CLAP/AU · Win/Mac/Linux) from Riverflux Audio. Frequency-aware phase rotation for L/R fights — not a polarity button, not a delay matcher, not a stereo widener. On guitar, use it after polarity and mic distance/timing are honest.
What dual-cab phase fights sound like
- Body / low mids gone in mono — thick stereo grit collapses to cardboard.
- One cab “wins” — flipping polarity on mic B suddenly restores weight.
- Blend knobs fight you — adding more of cab 2 subtracts instead of stacking.
- Reamp + cab IR stacks — printed stereo IR blends that hollow when summed.
Same physics as DI + mic and overhead/room fights: nearly identical content, different arrival times (and sometimes polarity), then frequency-dependent leftovers.
Honest fix order
- Polarity — flip each mic / cab path; keep the combination with the fullest mono sum.
- Timing / distance — nudge sample delay or physically match mic distance so transients align. Dual-cab stereo spread often needs a few samples, not a widener.
- Spectral phase (PHIXER) — only if mono still scoops after polarity + timing. Target the hollow band with From/To; keep Amount conservative.
- Stop — if the width is the point (hard-panned twin cabs as a stereo image), leave the fight and check mono with intentional thinness accepted.
When not to use PHIXER
- Mono single-mic cab takes — no L/R fight to repair.
- Obvious polarity or distance errors you haven’t checked yet.
- Intentional hard-panned dual-cab width you want to keep, mono be damned.
- Using a stereo imager to “fix” cancellation — width tools don’t restore cancelled energy. See PHIXER vs imagers.
Quick mono check
Follow the mono-check workflow: solo the dual-cab bus, flip to mono, A/B Amount. If mono body returns without killing the stereo interest, you’re in the right zone.