Rekordbox Audio
Sync DMXDesktop with Rekordbox using live audio detection
rekordbox does not support OS2L, and its Ableton Link support is follower-oriented: it will take tempo from a Link session more readily than it will publish its own, and tempo changes tend to need a manual nudge. This is not unique to rekordbox. Most DJ applications implement Link the same limited way, so the same caveat applies to Serato and others.
You can make Link work, but you will be managing the tempo rather than leaving it alone, which is not what you want mid-set.
The better route is Direct Audio Analysis: DMXDesktop listens to rekordbox’s audio output in real time and locks onto the beat and tempo itself, with nothing to configure once it is running and no dependency on what rekordbox chooses to broadcast.
There are several ways to route rekordbox’s master audio into DMXDesktop:
Option 1: Physical Loopback (Mixer → Laptop Input)
If you are using a DJ controller or mixer with a laptop that has a line-in or mic input:
- Connect a cable from the mixer's master/booth/rec output into the laptop's audio input.
- In DMXDesktop → Settings → Audio → Live Audio, enable Direct Audio Detection.
- Select your laptop's input device, enable it, and tick Update BPM.
This is reliable, but many modern laptops no longer include a true audio input.
Option 2: PC MASTER OUT + Stereo Mix (Windows only)
If you're running Rekordbox and DMXDesktop on the same laptop:
- In Rekordbox, click the PC MASTER OUT icon (laptop symbol in the top right). This outputs audio to both your DJ hardware and your laptop's speakers.
- On Windows, open Sound Settings → Input, right-click and enable Stereo Mix (if hidden, select "Show disabled devices").
- In DMXDesktop → Settings → Audio → Live Audio, select Stereo Mix as the input, enable it, and tick Update BPM.
Option 3: Virtual Audio Cable (Windows)
For a cleaner setup without laptop speakers blasting audio:
- Install VB-Audio Cable (free/donationware).
- In Rekordbox audio settings, set Master Output to CABLE Input (VB-Audio).
- In DMXDesktop → Settings → Audio → Live Audio, select CABLE Output (VB-Audio) as the input device.
- Tick Update BPM.
This routes audio silently into DMXDesktop, with no unwanted speaker output.
Option 4: BlackHole / Loopback (macOS)
On macOS, use BlackHole (free) or Loopback (paid):
- Install BlackHole.
- Open Audio MIDI Setup → create a Multi-Output Device including both your DJ hardware and BlackHole.
- In Rekordbox audio settings, set Master Output to that Multi-Output Device.
- In DMXDesktop → Settings → Audio → Live Audio, select BlackHole as the input device and tick Update BPM.
Final Step (All Methods)
Whichever method you choose:
- Go to DMXDesktop → Settings → Audio → Live Audio
- Enable Direct Audio Detection
- Select the input device carrying Rekordbox's output
- Tick Update BPM
DMXDesktop will now analyze Rekordbox's audio in real time and sync effects to the beat.
Choosing ASIO channels
On a multi-channel ASIO interface you can pick which input channels DMXDesktop captures, and which output pair the built-in music player plays to, instead of being stuck on channels 1 and 2. Channel lists show the real names from your driver, such as "MAIN OUT L", so you can tell which socket is which.
Most ASIO drivers allow only one program to hold an interface at a time. DMXDesktop warns you when two of its own features are pointed at the same device.
More reliable tempo on difficult tracks
Live tempo detection is significantly more accurate on the material that used to defeat it: ballads, acoustic sets, brushed drums and live bands. House and techno were never the problem.
The BPM Confidence meter alongside the reading tells you when it can be trusted, so a track DMXDesktop cannot read no longer looks the same as one it has read perfectly.
It now takes a couple of seconds longer to settle at the start of a track. That is deliberate: it would rather be right a moment later than confidently wrong for the whole song.
