To expand / correct what Dewdman42 said - you don't need to actually manually cable anything in the Environment window - just take a look at the screenshot below and do the following:
- Use the little "+" button at the upper left above the Tracks list in the Main Window to bring up the "Create New Tracks" dialog.
- In the dialog, select "Software Instrument", enable the "MultiTimbral" checkbox, and enter the desired number of MIDI channels you want for that instance, up to 16.
This will create a set of Instrument Objects in the Environment that all "point to" the same Instance of a Software Instrument, each Object on a different MIDI channel - but the entire set only uses
one of your available 255 Software Instrument slots. Since every one of those 255 slots is actually multitimbral (up to 16 MIDI channels per slot), the total number of discrete, single-MIDI-channel Software Instrument sounds you can access at any one time in a Logic project is:
4,080
Even though you'll see up to 16 Objects in your Environment, any changes you make to the controls on any one of those visible Audio Objects will be applied to all of them - they're all pointing to the same, single Instrument slot and audio path. So adjusting the channel volume fader, sends, adding processing plugins - these will apply to
all of the MIDI channels within that set. Think of it like a 16-channel "rack", or like an old Korg workstation keyboard that can have 16 separate sounds, but comes into your audio mixer via a single stereo pair. You'll have to use the individual volume settings for each Kontakt Instrument (or use MIDI Volume, aka CC#7) to adjust relative volumes between the sounds in the multi - the actual on-screen fader on the channel strip will adjust the master volume of
all 16 slots simultaneously (which is actually kind of helpful as a way to mix that whole "sub group" relative to everything else).
I use this method to address VEPro instances in 16-channel-wide "racks", and the same method works just fine for Kontakt, Omnisphere, or whatever other software instrument you use that is multitimbral. This is a great way to group sounds which can comfortably share the same audio routing, plugin chains, etc. In fact, it's a lot quicker and easier than using Track Stacks or Auxes or whatever, and might save on instances of plugins. You could put all of your "low strings - shorts" in one 16-channel Kontakt instance, have the next be "low strings - longs" etc. etc all the way to 4,080.
Of course, you may run up against Logic's dreaded "single core" issue, where
all of the instruments within any one of these multitimbral instances will need to fit on the single, last, "live" core of your CPU. So there's that little foible to look out for. If this gives you problems, it can often be reduced or eliminated by using the same approach to address a bunch of 16-channel wide VEPro Server instances, even on the same computer. Now that VEPro has the "tabbed" user interface for multiple server instances, I find this much more convenient that fiddling with the "Event Input" plugin in an effort to get around Logic's limit of 16 MIDI channels per plugin instance. I just run a new Server instance for each batch of 16 MIDI channels, and each one appears as a color-coded tab in a single VEPro window. If you do this, you can put individual instances of Kontakt in each of the 16 slots in each VEPro instance, and then you
can put individual audio plugin effects on each one, and control their relative volumes using the faders on the VEPro mixer - although they'll still return to Logic via a single, summed audio path - unless you start messing with multiple return paths, Aux Objects in Logic, etc. = more headaches. It works, but I avoid it due to hassle. Plus I think you're limited to 256 Aux objects, so you'll start running out of
those sooner or later.
When Logic and VSL both get around to fully implementing the AUv3 spec, we'll have true multi-port MIDI per plugin instance, so we'll all be rebuilding our templates when that rolls out. Hopefully around then we'll see a Logic update that raises the maximum number of available Instrument slots as well.
Another helpful tip you may or may not know already - when you want to rename all 16 of those Objects in the Environment Window, you can speed things up by selecting all 16 of them, then Command-Clicking on the first one, and entering a name like "Strings-1". If multiple Objects are selected, and a new name is entered, and the
last character in the new name is a number, Logic will helpfully increment the number for each of the selected Objects. The result will be that the 16 Environment Objects will be named "Strings-1", "Strings-2", etc. (unfortunately, leading zeros are not created, and are in fact ignored if you attempt to enter them, but no biggie)
This also works when you want to rename a bunch of audio or MIDI Regions in the Main Window, or just about anywhere else in the program where you can select and rename multiple things at once.