According the XP 80/60 Owner's manual, there are two pairs (stereo L/R) of output, one direct (no FX), and the mains with FX. This means that (proper) recording would have to be one midi track at a time.

I pointed out earlier the importance of intention. A question is begged: Why is the OP playing the XP-80's audio through the mackie instead of feeding it back into the PC and thus to Sonar?

Hmm.  If the audio is not going into Sonar, why not just turn the master volume on the XP-80 up and down?  I guess a photo would help at this point.

SuperG
According the XP 80/60 Owner's manual, there are two pairs (stereo L/R) of output, one direct (no FX), and the mains with FX. This means that (proper) recording would have to be one midi track at a time.

I pointed out earlier the importance of intention. A question is begged: Why is the OP playing the XP-80's audio through the mackie instead of feeding it back into the PC and thus to Sonar?

According to the XP-60 that I have sitting in front of me, you can specify whether each part of a performance is sent to "DIR" or "MIX" outs in effects section of a Performance, and pan each part individually in the Part section..  Hence four outs, as long as you don't mind mono and no effects.

jb101

SuperG
According the XP 80/60 Owner's manual, there are two pairs (stereo L/R) of output, one direct (no FX), 

According to the XP-60 that I have sitting in front of me, you can specify whether each part of a performance is sent to "DIR" or "MIX" outs in effects section of a Performance, and pan each part individually in the Part section..  Hence four outs, as long as you don't mind mono and no effects.

 
Correct, but not something to take for granted as most folks (not all..) would not be likely to think of doing that, and it mandates a four input interface.
 
We're still stuck on whether the OP even plans on recording or not....this whole thread pivots on that.
 

SuperG

jb101

SuperG
According the XP 80/60 Owner's manual, there are two pairs (stereo L/R) of output, one direct (no FX), 

According to the XP-60 that I have sitting in front of me, you can specify whether each part of a performance is sent to "DIR" or "MIX" outs in effects section of a Performance, and pan each part individually in the Part section..  Hence four outs, as long as you don't mind mono and no effects.

 
Correct, but not something to take for granted as most folks (not all..) would not be likely to think of doing that, and it mandates a four input interface.
 
We're still stuck on whether the OP even plans on recording or not....this whole thread pivots on that.
 

 
???

I think Konrad nailed it - why not just turn the volume on the XP80 up or down?   Regardless of whether that output is being recorded in real-time or just for monitoring the result should be the same.   For that matter, the same should apply to the mixer fader.    And now I'm confused... why would anyone try adjusting the output of multiple MIDI tracks as a group, rather than the output of the device being triggered?
 

stevec
I think Konrad nailed it - why not just turn the volume on the XP80 up or down?   Regardless of whether that output is being recorded in real-time or just for monitoring the result should be the same.   For that matter, the same should apply to the mixer fader.    And now I'm confused... why would anyone try adjusting the output of multiple MIDI tracks as a group, rather than the output of the device being triggered?
 

There's the odd case where you'd want that baked into the midi data itself, possibly in a live performance situation...

Just group the faders. 

OK, get a pedal.  Set it to CC 11 (Expression).  Set all the MIDI tracks to OMNI input.  Seems harder than a volume control but since we are all brainstorming....

daveny5
Just group the faders. 

+1