I reversed the channels on 1 set of waves before doing the listening because of the l/r swap I read about so I don't know how much it changes the results...but for me:
B had a more pleasant bottom end - a little tighter and there was somehow more 'feel' to it even though it didn't seem any louder.
B also had a smoother top end, which I appreciated in this recording. At all levels and over the 3 tracks, I consistently preferred B. 'A' seemed to be missing precision low down and was a little bit too much up high. So in matching with the brightness of the 41s, B was it for me.
I have no clue which would be the n-box or the sonosax since I don't really know much about them and have only heard one n-box recording. It was also with 41s and was placed right by my 184>UA-5 setup. They were different for sure! Actually, come to think of it, there was way more bottom end on the 184s so... I'll guess that source 'A' is the n-box. Another unknown factor would be differences between the pairs of capsules.
Thanks for the comp Brian! How many months will you beat yourself up over the sloppy work on the channels?