OK, that helps a little. Don't know about the apex mic.
The octacapture should have its own soft mixer - this is different than SONAR's internal mixer. It gets very confusing until you get the two coordinated. In SONAR's mixer there are three panels - tracks and buses and hardware. Each has to be hooked up to the next to make it easy to remember. The hardware in/outs will be ASIO names most likely. If you are using a different driver I don't know what the names specs are.
The octamom-capture also needs to be set up and the signal flow should be analogous to SONAR. It makes most sense if track 1 of SONAR goes to the master bus which goes to hardware output 1 (which is usually called mains). Coming in it is the same way. Octacapture input 1 should go to ASIO 1/2 (left) - yea, stereo is how the nomenclature works - which is choosen from a drop down menu in each of SONARs track.
If you are not getting a mic signal to sonar from the octa, it most likely is routing. Or input 1 & 2 just don't have preamps. Or the phantom power is switchable in 2s, not all at once. Or ... there are lots of reasons it ain't working. Those are the most obvious. Or the hardware channel is broke, like you suspect.
@
Ps, the maudio is the soundcard for all intents and purposes. Some people disable their onboard soundcard, but it at leasst needs to be disengaged from SONAR's driver choices. SONAR should be using the mauido's drivers, not MS something or other.