If Serato DJ Pro connects to the Xone DB4 or DB2 but you get no audio, or missing waveforms while using a Windows computer, you may be running into a known issue related to the mixer firmware.
First of all, we suggest you run through the Club Kit Setup Guide as well as the Xone DB4 & DB2 DVS Connection Guide to ensure everything is set up correctly.
If the issue persists, and it's not related to set-up of DVS, it's possible you have an older firmware installed.
To resolve this, please install the latest audio firmware (which can be found in the latest driver package, dated May 2018), which is version 1.20. It can be found under the following links - then by clicking the 'Software' tab, then 'PC Device Software', then the appropriate May 2018 Windows Device Software listing: