Ok, first off, this has nothing to do with s.rate/bit depth. You might be triggering 16 bit samples while your project is set to 24 bit - but that has no affect on the null vs. not null.
Secondly, KBJRock > any difference that there is (and there is a difference - more on that in a bit), you will not be able to hear. With respect, if you think you hear more lows or less lows in one than the other (mixdown vs. playing back and triggering MIDI data), you are imagining things. This is assuming that the levels are the same; that the master bus was at 0 when the mixdown was done. If it wasn’t - that’s a different story.
Finally, there is this. When you trigger mulitple Kontakt samples in succession, they do not always play back exactly the same. Why, I don’t know. I do not know if this is a Kontakt thing, or a Cubase thing. I have not tried this with PLAY…maybe I should. This is evidenced by loading a drum patch in Kontakt, creating a MIDI file which triggers a bunch of samples from that patch (they should not be RR samples - b/c then we will almost likely not have two nulling files regardless), and doing two real-time exports. Those two audio files will not null. Again, I don’t know why. AFAIC they should, but they don’t. Now, if you open say, a violin patch, and lay down say, three notes that are several seconds apart from one another, two resulting files from rt exports will null. Assuming there are no plugs with any randomness, and that there are no Kontakt inserts.
This is not a concern for me, b/c the difference is inaudible; it’s usually around -75db. Nobody can hear that.
Now the question is, how can I bounce this so that I´ll get a perfectly nulling audio track?
If you do two non-rt exports, those files will null. But a non-rt export will not null against playback, b/c remember - the samples do not always play back exactly the same.
Cheers.
–edit— just checked this in PLAY - same thing. It appears to not be a Kontakt thing, but a Cubase thing. Support ticket time.