At control panel I have assigned my sound card out 1-2 at monitor 1 and out 5-6 at monitor 2,I can not hard this two output simultaneously, is it possible ?

You are maybe talking about the control room…? in Cubase…? (Pro 8…?) VST connections…?

Yes I talking about that

No, they can only be heard individually - at least from Cubase. Your audio interface might let you route it so you can hear it on both depending on its capabilities.

Outside of the thrill hearing everything really big why do you want to do this? From an audio engineering point of view it will most likely introduce listening problems rather than giving you more accuracy.

when I working on cubase 6.5 it was possible,there my 4 stereo output was studio 1, studio 2, phone and monitor, here not founding studio out. my interface is roland octa capture

I supposed you’d have to use the cue mix. You could also use the Cubase headphones as studio 1, and output as studio 2. Set up in control room.

But unless you mean studio 1 is a different room to studio 2, where you might want to have them both on at the same time or not, there is literally no reason to use both monitors at the same time in the same room. if I’m wrong please elaborate.

I use Cubase Headphones for the input record monitoring. Then the 4 outputs are A: Mix Headphones, B: Monitors 1, C: Monitors 2, D: Hifi

On my audio interface, the master output is already the same as headphones, meaning A had to be headphones not the monitors, otherwise selecting it would still play both and i’d have to turn off my monitors. The Cubase headphones is the 2nd interface.

You have to think about it and get to truly understand how your equipment can work.