I inserted a soft synth, (a violin) and copied three takes from a former midi track to this new track.
The first of these takes is significantly lower in volume than the other two, on the new track.
Velocity bars are the same on all three. I've looked at events, but found no instances other than notes.
Wutthe? Wat? How?

What have you checked so far?

Exactly which soft synth?  Have you checked there is no automation present that could be doing this?

Thx, promidi!
No automation. I've checked "event viewer"(?) Nothing to indicate volume adjustments there.
Copied from a standard synth (with constant volume) to Kontakt-based violin. Also checked/compared velocity bars.

Don't know why this happened, but it's easily fixable with volume and/0r velocity adjustments.
Make sure you have put in starting volume events, using CC 7, and then expression events using CC 11. If you're using the Aria player with Garritan sounds, it's also best to put in a CC 1 event for the modwheel. In fact, it may be that that is what is causing the problem, whatever synth you are using. CC 1 controls the modwheel, so if you want to equalize the volume on the three takes, the modwheel would need to be the same. If the tracks were recorded using different synths, the volume and expression controllers would be the ticket. I use a variety of synths, and my keyboard has no modwheel, being ancient like me; but Garritan is the only library where I have to set the modwheel.

Thanks, Michael.
-Very useful, and for me, educational. That makes it very valuable. Thanks a lot!
This forum is amazing!

You're very welcome. I should elaborate a bit on the use of the CC events 1,7 and 11. 1 usually controls the modwheel on most software synths. Since my keyboard controller has no modwheel, I can adjust that with CC 1. CC 7 is what I use for starting volume. For example, on a software synth like Play or Aria, I may need to use different starting volumes for the flute, clarinet, violins, etc. Even though they're on the same software synth, some instruments may be natively louder than others. CC 7 allows you to normalize those differences. I only use CC 7 once, at the start of the piece. I usually set it at 80 or 100, or close to that. If an inst. is really way too quiet, I set it to 127. If way too loud, maybe 50 or 60. Then, I make "on the fly" adjustements with CC 11, which despite its name (expression) is really a fine-control volume adjustor. Along with velocity, these CC events allow you to have fine control over everything. Also some software synths have individual volume adjustments themselves, like Play (East West). And the synths in the mixer have overall volume levels. so there's all kinds of ways to adjust volume, which makes it confusing, but once you learn it all it all makes sense.

If you used an existing or former MIDI performance/sequence from a different synth than you are using now, I would recommend adjusting velocity or any CC's from Cakewalk's "Piano Roller Editor" window which can be opened by double clicking anywhere on the MIDI track.
 
There is also a really cool Cakewalk FX MIDI Velocity plugin that can be inserted to any MIDI track's FX bin. Same way you would add and apply an audio plugin to an audio track.

Thanks a lot guys!
I wonder if my Wacom pen tablet could do me any favours editing those parameters.. Maybe even for automation. Real estate on my desk is an exclusive feature. :)

This may not be relevant to your situation, but check if the instrument supports volume (Expression) via the mod wheel. This is common practice for orchestral instruments. Open Kontakt and see where the modwheel is positioned. If all the way down, push it up and see if your volume comes back.

Bitflipper's comment reminded me of something else, which is related: On Kontakt you need to set which controllers control which parameters. Click the advanced tab on Kontakt and set 11 to expression. Volume should by default be set to 7. I believe 1 is velocity cross-fade. I don't have my music rig on now so I'm not positive, but I'll check later and correct any of this if necessary.