DDJ 400 PC Master Out low volume when using Rekordbox

I noticed that the volume on my PC is quite low when i use DDj 400 WASAPI + PC Master Out in rekordbox. I can evem maximize the trim level without getting any distortion. Headroom is set to 0dB and auto gain deactivated. When i select my PC soundcard as audio device in Rekordbox, its much louder. But the problem then is, i cant use the headphone pre cueing, when i dont select DDJ 400 WASAPI. When i use Virtual DJ its also much louder with the same trim level. So is there any way to fix this or is this normal?