Tried to find the same problem here, but so far, no luck.

I'm sending 3 tracks of horns to the Aria player from Sonar Platinum.
 
No matter how I setup the tracks (Omni, or MIDI Channel 1,2,3 all matching in Sonar and the Aria player), the volume controls are funky, doing all kinds of unexpected things at different times.
 
I can't even narrow it down to WHAT they are doing, except to say that the volume are always changing. "Sometime" the volume responds to the Aria sliders and sometimes the Aria slider respond to the corresponding Sonar volume slider and move in unison, but not always.
 
This is a commercial MIDI sequence I bought from Hit Trax and I went into the event list to delete the controller 7's and added my own controller 7 number. I also just read that the CC1 and CC11 control volumes for Garritan, so I guess I'll go back and delete those controllers too.

My question is, how can I just adjust either the Aria player volume sliders OR the Sonar track volume sliders (and maybe even move together, but this wouldn't even be THAT important), while mixing so that I can hear how to adjust the volumes WITHOUT having to go into the event list and guess at number values and enter them there?
 
It's so very slow and time consuming to do this.
 
Thanks.

These Garritan products use CC1 for volume/expression, CC7 for mixer volume, CC11 for expression (again?) and CC2 for breath control. There is a note in the documentation:
 
In addition to the Mod Wheel (CC#1) World Instruments will also respond to breath control (CC#2) and MIDI expression (CC#11) to control the function of expressive volume/timbre. Be careful to use only one at a time or the data between these controllers will cause interference. It is not necessary for the user to take any steps to activate these extra controllers. They are always active.
 
Having used these libraries, I would suggest creating midi automation lanes for, at a minimum, CC1, CC7 and CC11. Then you can use the mouse to adjust these as the song progresses, but at a minimum, you can set an initial value for each controller as a starting point.
 
Regards,
Dan

AFAIK, volume in Aria player is mapped to mod wheel. If you didn't program your midi sequence for saxes, that seems to be the case. I also would like to know how to easily remap CCs and toggle controllers on/off.

A few other points/approaches to working with Aria Player:
 
First, disable Zero Controllers When Play Stops in preferences. Otherwise, SONAR will reset Modulation and Expression to 0, silencing Aria every time you stop the transport. Additionally it's a good idea to to have one each CC1 and CC11 events at the start of the track for Controller Searchback to read. This will prevent the synth being silent when playback restarts, but you'll still want to leave Zero Controllers disabled so you can rehearse when the transport is stopped. 
 
Next, right-click any MIDI track Volume control that doesn't have parentheses around the value (indicating it's disabled), and choose Disable Control. Now you can set initial volumes in Aria's mixer, and they'll stay that way. Moving a MIDI Volume control makes it active again, and it will send CC7 every time playback starts. Usually this is a good way to set initial volumes without having to go into the plugin UI, but I would disable them for the time being until you know for certain that you want to use them.
 
Now use CC11 (or CC2 as Dan mentioned) to change performance volume of each instrument as needed, and use audio track Volumes/Automation with one track per output from Aria Multi to do final mixing.