Offizieller Kommentar
Hi James - rekordbox allows for you to use what's called "PC MASTER" output mode where you select the DDJ-400 as your primary audio device, but you can then select whichever audio device is set as the default for your operating system (in your case, the laptop's speakers) as the secondary output. Even if you didn't have anything connected to the DDJ-400's outputs, you could use it for your headphone cueing, and the laptop speakers would play the master output audio.