So I went to the place we practice where my PA is set up last night to see if I could recreate last weekend's issue. Ran the ASM12 out of the left, direct to the X32 out of the right. The patch I used was the bone stock Plexi Treble patch with the top end rolled off a little boosted with a TS. A\B'd the ASM and PA speaker and they sounded great and VERY similar, to the point that any difference was negligible. Obviously some minor tonal difference because of different speakers, eq, blah blah blah but overall VERY close and better than I can do with a mic.
So the short version......I have no idea why it sounded different? Maybe it was the sound company's PA (compression, eq, effects, etc)? Impossible to tell at this point.
Thanks to all for your input!