I own 2 X32s and consider them an incredible piece for what they cost but use them for live only. In the studio I want lower noise floor, very low latency for tracking with VSTs / amp sims and 96kHz.

I have now just started experimenting with X32 and Splat I am curious to how you have routing setup on the X32 for recording and playing back tracks in Splat?  When I first started I could not get Splat audio to play through X32. By accident I was messing around with the routing, Home tab, on the X32 and changed inputs 25-32 to card 9-16 and changed my master out on Sonar to stereo 15/16 out because that is the mains for x32 and I finally got a signal on x32 on channels 31 and 32. Does that mean even though X32 has up to 32 inputs the usb is only going to see 16 and does that mean channels 17-32 are basically 1-16 output channels?  I sure hope now

eric_peterson
We are gigging with the X32 and I use SONAR to capture the performances. It works very well and the sound is excellent! I liked it enough that I bought a second X32 and S16 for the studio.

How do you have X32 configured to use for recording with Sonar?

BMOG
... I was messing around with the routing, Home tab, on the X32 and changed inputs 25-32 to card 9-16 and changed my master out on Sonar to stereo 15/16 out because that is the mains for x32 and I finally got a signal on x32 on channels 31 and 32. Does that mean even though X32 has up to 32 inputs the usb is only going to see 16 and does that mean channels 17-32 are basically 1-16 output channels? ...

There are a couple of X32 setup options that you've probably missed:
 
On the 'Setup>>Card' screen you'll see that it has combinations of 32in/32out at the top of the list, and all other combinations of 16in/16out, 32in/8out (I use this for my Sonar config), 8in/32out 8in/8out and 2in/2out. 
 
On the 'Routing>>Home' screen, I use the 'Aux-in Remap' column set to Card 1-6.  In that way, the other four columns of Inputs 1-8, 9-16, 17-24, 25-32 are contiguously dedicated to inputs. 
 
By default, Sonar's master output will go to the 1-2 output pair of the Card 1-6 which is mapped to the Aux-In.  The physical 15/16 output of the X32 is the main-L/R and can be engaged for any input, including the Aux-In.
 
I think these facts should help you get things sorted.
 
 
 
 
 
 

The only thing I would add to Garymedia's excellent summary is that the other cause of not seeing all of the expected I/O asside from the X-usb card setting is the driver mode option under Sonar preferences. If it is set to Wasapi you will only see 16x16 irrespective of the X-32's settings. It should be set to Asio.