I'm running Sonar X3 and Native Instruments Kontrol.  Since Kontrol doesn't really have an easily accessible volume control and I use the Setlist on Sonar 95% of the time, can I use one audio interface for Sonar and another for Kontrol and still keep it all on one computer?
 
Thanks for the help.
 
Greg

it could work fine, but personally would not try 2 interfaces on 1 computer. 
again, could work fine depending on the interface and it's settings/drivers but you could be in lot of troubles in Windows sound and Sonar/Kontakt.
Would look for another solution to control volume

Sheanes
it could work fine, but personally would not try 2 interfaces on 1 computer. 
again, could work fine depending on the interface and it's settings/drivers but you could be in lot of troubles in Windows sound and Sonar/Kontakt.
Would look for another solution to control volume

 I have 4 systems using multiple audio interfaces and onboard sound.  I use their control panels and make sure they are not mapped through Windows sound. The OP could add a low price Behringer external mixer.  

then maybe check first if a mixer would not increase the Daw roundtrip latency.
(I dont know if there's zero latency hardware mixers)
 

or maybe check with Kontakt forum/users how they control volume (if you hadn't allready)
 
 

Sheanes
then maybe check first if a mixer would not increase the Daw roundtrip latency.
(I dont know if there's zero latency hardware mixers)
 

 They are zero latency because they are analog.

curious, you would not be in and out of your interface / Daw and no digtial/analog and back converting ?
 

Another concern (in addition to latency) is something needs to be the master clock. If volume control is the primary concern, there are control surfaces, phone apps, and MIDI controllers that can be set up with this functionality more easily. Any MIDI controller with a knob/fader can be assigned to a parameter within SONAR. As soon as you head down the path of "audio interface" the latency/clock/driver usage may cause an undesired impact (but I have never attempted this either).

Kontrol is not an audio interface at least from what I can tell.

Kontrol is a new platform from Native Instruments to make all of their sounds work with a dedicated controller.  On the keyboard controller there is no volume control for the software- Native Instruments didn't think about anyone ever using the setup in a live setting (I got that info from tech support at Native Instruments).  Because of the way I do my live rig, I'm currently using 6 audio outs - pre-tracked horns, BGVs, other keys- from Sonar to send to the FOH to mix based on the room, the volume of the drummer or other players.  With the way Kontrol works, it shares the ASIO driver and lets me merge the outs from Kontrol to a pair of outs on my audio box.  The frustrating problem is that the sounds in the Kontrol insturements (Kontact, Massive, etc.) are not the same levels.  The solution Native Instruments gave was to go through my library of sounds and edit each file so that it is the volume I need it to be.  Of course this sounds good on paper, but playing live is a totally different story.
 
The only 2 options I can see are:
1.  use 2 interfaces so I can have hardware control over the Kontrol software
2.  Scrap the idea of having Kontrol on stage.