L output not wokring for DDJ-RB

Hello.

I just bought the DDJ RB and bought the right AV/ AUX cables for it. But for some reason when I only plug in the red one the sound is good. So then the sound is just coming from the right speaker. When I plug in the other cable, the L side, the sound disapears and is very bad. The bass is almost gone and it isn't proper sound. 

I already changed the cables to new ones, because I thought the cables were the problem, they aren't.

How to fix this? Or is the L output on the master out on the console itself broken?