Can I record in Serato DJ using my Numark Mixdeck or Mixdeck Express?

Due to the configuration of these controllers, recording in Serato DJ is not possible. All controllers are built differently and in order for these controllers to give users the benefits of an affordable controller/standalone mixer (among other features) they don't provide a master audio stream back into the software to be recorded.

For the same reason, the master output will not be represented in the Master Output Level Meter and the Master Output in Serato DJ, cannot be adjusted.

To record using these controllers, you can run an RCA to 3.5mm cable from one of the controller outputs into your laptop and then use 3rd party software (e.g. Audacity) to record your mix.