Backline

What it is

Backline is the patch organizer for backline gear on the tech side of the stage — Kemper Profiler and Neural DSP Quad Cortex to start. Per song, per device, it stores the patch recall (Bank Select + Program Change for Kemper, or a scene CC for Quad Cortex) and fires it — from a big-button Performance View, or automatically when Rundown changes songs.

Requirements

• macOS
• A MIDI interface connected to your device(s) — DIN in and out on the interface if you want echo-back/capture from the hardware
• A Kemper Profiler (firmware 2.3.0 or later recommended) and/or a Neural DSP Quad Cortex
• Wired USB MIDI (no Bluetooth) for show use
• For Rundown integration: same local network, OSC on UDP port 5685

Install & first run

1. Download Backline from the Mac App Store.
2. Open Backline.
3. Add each device (Kemper and/or Quad Cortex), set its MIDI in/out ports and channel.
4. Build a setlist, and for each song set the patch recall for each device.
5. Use the Performance View to fire recalls with a tap during a show, or let Rundown drive it automatically.

Common questions

Does Backline need MIDI SysEx to work?

No. Version 1 uses Bank Select (MSB/LSB) + Program Change for the Kemper, and a scene Control Change message for the Quad Cortex — no SysEx required.

Can I use Backline without the rest of the suite?

Yes. Backline is designed to work standalone — a guitarist who's never used another Performance Percussion app gets the full product on its own.

How does Backline know when to change patches?

Either you tap a song in the Performance View, or, if Rundown is running the show on the same network, Rundown advances the setlist and Backline follows automatically.

Can I export my setlist to my Kemper's own performance list?

Yes — Backline can export a setlist to a Kemper performance list so your setlist programs the hardware directly.

Does Backline confirm the patch actually changed?

Backline listens for echo-back from the Kemper so a device's status can show as confirmed rather than just sent, and it can detect when you change patches by hand on the device (capture).

Troubleshooting

A device never confirms after firing. Check that both MIDI in and out are connected and set correctly for that device — echo-back/confirmation needs both directions.

Rundown isn't advancing Backline's recalls. Confirm both apps are on the same local network and that Backline is listening on its OSC port (5685); check for a firewall blocking local traffic.

Quad Cortex scene doesn't land after the preset change. The scene message needs to be sent after the preset change lands on the device — if it's arriving too early, increase the device's post-Program-Change delay setting in Backline until it lands reliably.

Wrong performance/slot selected on the Kemper. Double check the device's Fire Method setting (there are two supported methods) and the MIDI channel configured in Backline matches the Kemper's MIDI setting.

Known limitations

• Exact timing values (minimum safe spacing between MIDI messages, Quad Cortex scene delay) are still being tuned against real hardware — if you notice misfires, try increasing timing/delay settings for that device.
• Version 1 supports Kemper Profiler and Neural DSP Quad Cortex only; other backline devices aren't supported yet.

Still stuck?

Email [email protected] with "Backline" and your app version in the subject line.