Riverflux Audio · Stem delivery mono-check
Check stereo stems for phase before delivery
Client stems, remix packs, and sample packs often leave your room sounding huge and arrive thin on a phone. Mono-check stereo stems and session stems for phase before you ship. PHIXER is free continuous stereo phase repair (VST3 / CLAP / AU). It is not a time-aligner.
Download PHIXER free Watch tutorial
Hard clarify: Fix polarity and timing on dual paths first. Use continuous phase rotation only when a stereo stem still hollows in mono after that hygiene. Do not "fix" creative Haas width the client asked for.
Why stems fail after delivery
- Headphones lie. Wide pads, stereo FX, and stacked one-shots can cancel when the listener folds to mono (phone, Bluetooth, club mono sum).
- Stem buses recombine. A drum stem that passed alone can fight the bass stem once the client sums groups.
- Remix / sample packs travel. Other producers will throw your stereo files into new sessions. Mono-safe delivery protects your reputation more than another 2 dB of width.
Delivery habit (client stems / remix / sample packs)
Before you bounce the pack
- True L+R or Utility Width 0% on each stereo stem (and a phone speaker pass).
- Note what disappears (kick body, bass, pad low-mids, layered FX).
- If dual-mic / DI+cab / top-bottom still late or flipped, fix polarity and timing first (phase rotation vs time-align 2025).
- Only then nudge PHIXER on residual spectral L/R fights. A/B with the plugin bypassed.
- Re-check after any stem bus glue or pack limiter. Ship only when mono still has body.
Where PHIXER sits for stem work
- On the stereo stem print when that file is the deliverable (client vocal stem, remix drum stem, sample loop).
- On a stem bus when groups recombine and cancel only when summed (stem bus / stem delivery phase).
- In a mastering-style chain after tone/glue, before limiter, then mono-check (mastering chain placement).
When not to "repair" a stem
| Situation | Right move | PHIXER? |
|---|---|---|
| Kick in/out or DI/cab still late | Time-align upstream | No |
| True mono source | Polarity only if needed | No |
| Creative Haas / width the client wants | Keep stereo art; offer a mono-safe alt if asked | Usually no |
| Stereo stem still cancels after hygiene | Continuous L/R phase by band | Yes |
Honest limits map: when not to use PHIXER.
Related guides
- Where PHIXER sits in a mastering chain
- When not to use PHIXER
- Phase rotation vs time-align 2025
- Stem bus / stem delivery phase
- PHIXER for stems
- YouTube tutorial · Intro
- Gumroad download
- Remix contest / DJ edit pack phase-check
Takeaway: Mono-check stereo stems before delivery. Polarity and timing first. Continuous phase only for leftover spectral cancel. If timing owns the problem, skip PHIXER (when not).