Sound Output U-Mix44 / Cross / Mac OS X 10.10

Hey Guys,
I'm really sad. I looked around every forum and community to find a way to get my U-Mix 44 Soundcard working correctly.
I just get 1 Output working, even if this soundcard is supported as 4x4
card.
I found a lot of ways and tutorials, but noting worked.
I also tried the step-by-step tutorial by stealthii here in the forum.
Nothing... I can't use the External Mixer Mode for my Setup.
I read every manual and every tutorial and support page and so on, but I never find a working resolution...
I also tried different Versions of Cross.
My Setup is
MacBook Pro 15" Retina Mid 2014
OS X Yosemite 10.10.2
Cross DJ 3 (latest Version)
Interface: U-Mix 44
Mixer: Behringer DJX700
Turntables: American Audio TTD2400
Turn 1 is in Input 1 from Interface
Turn 2 is in Input 2 from Interface
Mixer Chan 1 in Output 1
Mixer Chan 2 in Output 2
Like a normal DVS... (Yeah... New MacBook, old Techs^^Turns and Mixer are working really great :P )
But I just get Sound out of the 1 Chan from the interface and I really don't know how to fix this...
Thanks for your help
Greetings
Dennis
I'm really sad. I looked around every forum and community to find a way to get my U-Mix 44 Soundcard working correctly.
I just get 1 Output working, even if this soundcard is supported as 4x4
card.
I found a lot of ways and tutorials, but noting worked.
I also tried the step-by-step tutorial by stealthii here in the forum.
Nothing... I can't use the External Mixer Mode for my Setup.
I read every manual and every tutorial and support page and so on, but I never find a working resolution...

I also tried different Versions of Cross.
My Setup is
MacBook Pro 15" Retina Mid 2014
OS X Yosemite 10.10.2
Cross DJ 3 (latest Version)
Interface: U-Mix 44
Mixer: Behringer DJX700
Turntables: American Audio TTD2400
Turn 1 is in Input 1 from Interface
Turn 2 is in Input 2 from Interface
Mixer Chan 1 in Output 1
Mixer Chan 2 in Output 2
Like a normal DVS... (Yeah... New MacBook, old Techs^^Turns and Mixer are working really great :P )
But I just get Sound out of the 1 Chan from the interface and I really don't know how to fix this...

Thanks for your help
Greetings
Dennis