gswitz, many thanks for your reply! Good to see the Sonar forum is full of helpful users.
I have solved the problem, Akai MPK49 in fact works perfectly with ACT in Sonar X3.
To help potential Akai MPK49 users, here are the steps I did:
1) Initializing the controllers on MPK49, either manually or use the excellent Vyzex editor (came with MPK) on computer. Set each controller to "Common Channel (CC)".
2) Set the desired channel (e.g. 1A) in the Global setting on MPK49 for
assigning the "Common Channel (CC)" that individual controllers are set to.
3) Presume the MIDI driver is correctly installed, in Sonar X3, under Preferences > MIDI > Instruments, in the first "Output/Channel" set MPK49 as <default> under "Uses Instrument". Note: MPK49 is always set as <default>, read P.7 in Akai MPK49 Reference Manual.
4) Under Preferences > MIDI > Control Surfaces, create "ACT MIDI Controller 1" by clicking the yellow star button at the upper right hand corner. Choose MPK49 for "In Port" & "Out Port". Check ACT & WAI.
5) Click the "Controller/Surface Properties" at the lower left hand corner of the ACT module (right click to select ACT module if it is not in the Control Bar in Sonar), click each green assignable area to MIDI learn the MPK49 controllers. Finish this process and you can fully control the knobs, faders and buttons in Sonar X3 on Akai MPK49.
post edited by modalmojo - 2014/05/16 00:41:41