Set CC1 to a higher value early in your track...by default many orchestral libraries use CC1 or CC11 for dynamic control. Some instruments might call it 'expression volume' while others might call it 'crescendo control'. Whatever volumes are set this way stay 'relative' to the main channel volume (CC 7). This way you can adjust the over all channel volume (CC 7) of a track to work it into a mix, while preserving various dynamic characteristics (CC 1, or 11, etc.) of the part itself.
Why yet another parameter to keep up with? Well...acoustical symphonic instruments are extremely 'dynamic'. The scores call for all kinds of nuances ranging from subtle changes, to really radical ones. I.E. Sforzando style attacks...crescendos, etc. Moving all this stuff around throughout a track is what makes a more realistic sounding performance, as opposed to an overpriced computerized sounding organ.
Here lately, it seems to be something of a standard for 'score translation' software (I.E. Finale, Sibelius, and CuBase score mode) to use CC1, and make frequent adjustments to it to get more realistic 'dynamics' out of the score translation. If you ever watch your VSTi's (with a proper instrument profile for your VSTi) mod wheel while one of these score packages is interpreting a score, you'll most likely see it bouncing around for nearly every single note! Of course only using note-on Velocity to get different dynamics in a phrase is still an option as well (typical for simple GM, GM2, or XG instruments).
CuBase's score translator will let you choose between CC events, note on velocity, or a combination of the two when it comes to interpreting the meaning of things like crescendo hair pins, or dynamic markings like forte, piano, etc. It's done by a combination of score editor settings, along with 'expression maps' that you make to teach the score editor how to 'interpret' marks on the score.
Better Orchestral Libraries will start steering you towards using velocity to change 'attack or articulation' styles, and use CC1 or CC11 to alter dynamics. HSO gives you 'choices'...so you can match it up to whatever your DAW or Score package requires, or what ever better fits your composition style and needs.
Don't forget that you can use the HSO UI to change the HSO dynamic mode to other forms of expression control. If you want to use the mod wheel for something else (I.E. an lfo for vibrato), you can have it use some other CC instead of CC1 (mod wheel) for expression. CC 11 is defined in the MMA MIDI standards for this purpose, and it's not unusual for people to use a breath (CC 2) or foot (CC 4) controller as well.
You can also change this behavior if you're using HSO presets with Halion 5 rather than the HSO plugin.
If you like to grab general MIDI files from various archives, you might find it a bunch easier to change HSO to velocity mode instead of mod-wheel expression. In fact, some people would rather use the note-on velocity mode anyway...it's up to you
When using CuBase I like to leave HSO (and other orchestral libraries that use CC1 or CC11 for dynamic expression) at the default settings with mod-wheel expression volume mode, but I'll run a quick logical editor pass that inserts CC1 before every note at the note value. I.E. If the MIDI note is 100, then a CC1, 100 event gets inserted right in front of the note (shows as an event at same clock value as a note on event, but it actually gets sent right before the note on so the MIDI or VSTi sets the volume relative to the master channel volume before playing the note).
Insert CC1 before every note event and set value 2 of CC1 to value 1 of the MIDI note.
What this does, is cause the volume to go up as the phrase gets higher, and down as it gets lower. Of course you can also do this backwards if you prefer (mirror MIDI note)...or even build a script to randomize or set up other sorts of dynamic patterns.
Note that it's also easy to lasso a group of events in the key editor and scale/tilt/expand/compress them...or otherwise work with them as a big unified group. Experiment by holding the mouse button while lassoing a group of events...also with things like holding ctrl or shift key while dragging (it can lock the x or y drag plane...etc).
At this point, if it's too soft, I can lasso phrases as above and drag it a bit louder...or I can run a second pass with a logical editor to raise all of the CC1 events on the entire track by a set uniform amount.
Raise all CC1 events by adding 5.
Finally, I can go in and edit any individual note dynamic levels that might need it.
If I have a phrase where the same note repeats over and over, I'll again use the logic editor to give that passage some 'random' volume and velocity settings to avoid getting a 'machine gun' effect.
Move the selected CC1 events to a random value within a given range:
If there is a lot of 'block cording' going on in a part, I'll go back and 'thin MIDI controller' data to avoid really large unwanted jumps in volume during said 'chords'. A quick visual inspection of such tracks isn't a bad idea...as too much jumping around while a chord sustains might be unwanted...just delete the CC1 events that don't work in the interest of the musical phrase.
Here you can see a violin phrase (actually two second violins on the same track [divisi style]) that has some Fp, sFz, and multiple notes/chords going on. I got the basics running some logical editors, then drew in (or recorded using my mod wheel) my crescendos and whatnot.
Don't forget that you can still change the over all mix of the track using the CuBase Mixer, or via Master Volume Control in a MIDI track or automation lane (CC7) without having to redo all your detailed general dynamic stuff that you did with CC1 (or CC 11, or whatever) events.
While this might sound like a lot of trouble, it actually only takes a few clicks to select any parts I want to do this for in the logic editor, and a few more clicks to do everything described above. The result is a more natural sounding track (in most cases).
1. Right click a MIDI track and choose 'select all events'.
2. Open the Logic Editor.
3. Build my script or load one of my logic editor presets.
4. Click apply!
5. If I haven't already, and I think I'll want my little logic script again in the future...save a preset of it.
It's really that simple
The gist of this is...make use of the CuBase logical editors! With a little practice, you'll be amazed at what all they can do. Not only does this work for CC controllers, but you can also do it with key velocity, and so much more. It really can save a whole bunch of 'single note editing', and lead to more natural/realistic sounding phrases.