Play out live — decks, headphone cue and a controller

You want to stand behind a laptop and mix by hand. This is the whole path, in the order you'll need it.

Everything here is on the Decks screen, under DJ.

1. The audio engine starts itself

Open Decks and look at the AUDIO ENGINE bar in the library drawer. It should already say something like 4.4ms · 0 dropouts.

That's the native engine — a separate audio path built for playing live. It runs at around 4–6ms where the browser's audio sits at 10–25ms, and it starts on its own. Nothing to switch on.

OUT picks which device the room hears. It defaults to real hardware and deliberately avoids Bluetooth speakers: a Bluetooth connection adds about 200ms of delay that no software can undo, so if your default output is a Bluetooth speaker, the decks will feel wrong. Plug in, or pick a wired output.

Dropouts is the number to watch. Latency you can live with; a dropout mid-set you cannot. It should stay at 0.

If the bar says built-in audio, the engine couldn't open a device and the board has quietly fallen back to the older audio path. Everything still works; you just won't have the cue.

2. Hear the next record before the room does

You need a way to preview a track in your headphones while something else plays out. Two ways:

With an audio interface or a controller that has one

Pick it under CUE. Master goes to one output, headphones to the other. This is the better option if you have the hardware — you keep stereo on both.

With one output — Split Output

Tick SPLIT, then plug a Y-splitter (one 3.5mm plug, two sockets) into your headphone jack.

• Left channel → the room
• Right channel → your headphones

This is how most laptop DJs cue and it needs no extra gear. The trade is that both feeds are mono while it's on — you're spending the stereo image to get a cue bus.

Split and a separate cue device are mutually exclusive. Choosing one clears the other.

Then, on each deck

A 🎧 button appears on the deck pads once a cue path exists. Press it on the deck you want in your headphones. The room keeps hearing whatever is on the other deck and the crossfader.

3. Load records

The bottom of the screen is a two-pane browser.

• Left — your set folders. Press + to make a new one.
• Right — what's in the folder you picked, with a search box.

Drag a row onto a deck, or open a folder and the decks will feed themselves from it: while one deck carries the room, the free one cues the next record from that crate automatically. You still move every fader — this only stops you hunting for the next track with a crowd waiting.

All music at the top of the folder list goes back to the whole library.

You can also drop a file straight from the Finder onto a deck pad.

4. Mix

Each deck has:

Double-click any control to reset it.

The moves

Three buttons on each pad do the things a record does:

• ↺ Backspin — the record reverses and stops, the way a hand spinning a platter backwards

sounds. It decelerates rather than running at a fixed reverse speed.

• ⊙ Brake — a turntable power-off. The record slows to a halt over about a second.
• ⤴ Pull up — spins back and drops the record again from the top. The restart is timed off the

audio clock, so it lands exactly where the spin ends.

These need the engine running. If it isn't, they say so rather than doing a worse version quietly.

5. Connect a controller

Plug it in — before or after opening the app, either works.

Press the 🎹 button in the engine bar. It shows the connected device and how many controls are mapped.

Set it up

Press Set up my controller and follow the prompts. It asks for twelve things in the order your hand finds them — both channel faders, the crossfader, play, cue, bass, pitch, headphone cue — and you just move each control as it's named. Skip anything your unit doesn't have.

Two minutes and you're mapped. It binds whatever moves the most, so brushing a neighbouring knob on the way won't steal the binding.

Or map one control at a time

The panel lists every action with a learn A / learn B button. Press one, move the control.

Share it

Export… writes a small file. Anyone else with the same controller can Import… it and skip setup entirely. If you map a controller properly, that file is worth sending to whoever asks — it's how the list of supported hardware actually grows.

What isn't supported

Worth knowing before you turn up to a gig expecting it:

• CDJs and XDJ players (CDJ-2000/3000, XDJ-1000) don't speak MIDI. They use Pioneer's own

protocols and need a licensing agreement, not a setting.

• DVS / timecode vinyl isn't implemented.
• Jog wheels aren't mapped by the setup flow. Buttons, faders and knobs are; scratching needs

per-model work.

Class-compliant MIDI controllers — most DDJs, Numark Mixtrack and Party Mix, Hercules DJControl, Reloop, Novation — work through guided setup today.

If something's wrong

No sound. Check OUT is the device you're actually listening to. A virtual device like BlackHole is silent by design.

Everything feels late. You're probably on a Bluetooth output. Nothing in software fixes 200ms of codec delay.

Dropouts climbing. Something else on the machine is competing for CPU. Close it, or pick a larger buffer.

Controller does nothing. Open 🎹 and check it's listed. If it is but a control doesn't respond, learn that one control again — a shipped or shared mapping can be wrong for your firmware.