Yep, that's right.
Inputs and outputs are those which you enabled in Preferences -> Audio -> Device. Listed as left, right, stereo pair, multichannel
(at least I think
the latter come up if your device has more than 2 I/Os. Mine, like yours, hasn't so I'm not sure there). Plus the Rearoute in and outputs if you have them installed (you have, otherwise they wouldn't be listed in your picture
)
So, if you enable the USB interface as your audio device in the prefs this is what will come up in several places in Reaper
- the routing matrix,
- track audio input selection (the same as the inputs in the routing matrix)
- audio hardware output sends in track (and master) I/O windows (the same as the outputs in the routing matrix)
Hope that helps
I can't resist to plug my main Routing Matrix niggle: MIDI in/outs are not reflected in the routing matrix - which makes the matrix represent only half of my routing. Would be quite cool if I could use the matrix to set up my projects, but I can't
.