Can't internal mix mode with a DJM-900SRT!!

Hi all,

Is it possible to use the DJM-900SRT and Rekordbox INTERNAL mix mode ?

I've plugged laptop into a DJM900SRT.

In Rekordbox DJ preferences INTERNAL mix is not available, only EXTERNAL mix.

Why cripple internal mixing in Pioneers own Rekordbox when used with Pioneers own mixers?

I want to be able to use the DJM-900SRT and Rekordbox Dj with a midi controller.