PHIXER for Bass DI: DI + amp dual path that keeps low end on mono fold
DI plus amp, cab mic, or cab IR can feel huge in headphones. On phone playback, Bluetooth, club PA mono, or livestream fold, the fundamental thins and note attack softens. Polarity and timing come first. Free phase-repair helps after residual L/R fights remain on a stereo bass bed you must keep stereo. It is not a bass enhancer, and it does not replace a true mono listen on the bass bus.
Download PHIXER free YouTube tutorial
PHIXER is free stereo phase-repair (VST3/CLAP/AU · Win/Mac/Linux) from Riverflux Audio. Frequency-aware phase rotation for leftover L/R fights on stereo material. It is not a polarity button, not a delay matcher, not a widener, and not a DI reamp. Use it after hygiene, when residual spectral cancellation remains on a stereo bass bed you must keep stereo.
Three bass failure modes this page covers
- DI + amp / cab mic dual path. Fine in cans; thin fundamental on phone or mono fold. Deep guide: Bass DI + amp/cab phase.
- DI + cab IR / amp-sim wet blend. Impulse or sim latency vs dry DI that cancels mid-bass when summed.
- Synth stack cousin. Near-copies on two paths hollow the same way a stereo bass blend can. Cousin guide: PHIXER for Synth Layers.
Fast bass mono audition (about 60 seconds)
- Sum L+R on the bass bus or master (or monitor controller mono). Listen to fundamental, note attack, and mid grit.
- A/B stereo vs mono. Note what disappears: low fundamental, pick definition, cab body that was actually cancellation.
- Mute amp/cab or IR briefly. Flip polarity on each path. Note which combination restores mono weight.
- Confirm on a phone speaker or single earbud path, then again after any bus compressor / EQ / saturation pass, not only before cleanup.
Honest order of fixes (before spectral phase rotation)
1. True mono listen on the bass / program bus
Hard L+R sum or monitor mono. Habit: bass DI + amp checklist and mono check workflow.
2. Hero path before width layers
Prefer one clear hero for low end (usually DI for fundamental). Amp/cab for grit and air, not as a second stereo width layer that steals Mid from the hero.
3. Polarity if a path flips
Inverted reamp, flipped cab mic, reversed interface. Flip Ø when fundamental returns. Guide: polarity vs phase.
4. Timing / delay-align before spectral tools
Amp sim or IR latency vs dry DI needs a few samples or ms, not a widener. Prefer aligning critical lows to the hero path.
5. Only then audition residual L/R spectral fights
If a stereo bass bed must stay stereo and fold still hollows a band after the steps above, gentle frequency-aware phase rotation can help. Prove it with mono A/B. Watch the YouTube tutorial and the mono demo.
Bass path types
| Setup | Common mono failure | First fix |
|---|---|---|
| DI + cab mic | Fundamental dips when summed | Polarity; mono listen; quieter cab |
| DI + amp sim / IR | Mid-bass hollows on phone | Align latency; quieter wet |
| DI + stage mic bleed | Room delay cancels attack | Mute test; polarity; quieter bleed |
| Upright DI + mic cousin | Same dual-path scoop on fold | Upright bass guide |
| Synth stack cousin | Near-copies hollow like DI+amp | Synth layers guide |
Synth layers cousin (short version)
- Unison or stacked synth layers create the same mono-fold shape as DI + amp near-copies on a bass bed.
- Sync and polarity still come first. Spectral tools after residual L/R fights only.
- Full write-up: PHIXER for Synth Layers.
When not to reach for PHIXER
- Wrong polarity on DI or cab (flip Ø first).
- Obvious IR / amp-sim latency vs dry DI (align first).
- You only need a true mono print from one hero DI (print mono; do not fake stereo width).
- Hard-panned intentional width where stereo story matters more than mono body.
- Honesty list: When not to use PHIXER.