Is it possible to still do keyboard splits when controlling external hardware synths?

Yes. When setting up to control external hardware, you must use the Zone Master function. The MODX can transmit on 8, count them 8 MIDI channels at a time. You will see several 8 Part Performances in the Presets… in those all 8 Parts are internal.

You can substitute an external device for one or more of the 8 KBD CTRL (Keyboard Control) Parts.
In other words, you could simultaneously play 7 internal Parts and designate one of them as an external Zone Part; or you could play 6 internal and 2 external Zones, or any combination, through to 8 external (at max).

The concept I’m explaining is you replace addressing an internal MODX Part by substituting your external device.

I set up the key range the same way I normally would but it still plays every key as if the key range isn't there.

The Key Range as you normally would set it suffices for the internal tone generator… that parameter determines what that internal Part is going to respond to… NOT what is transmitted Out via MIDI. What you want to do is work with the Zone Master function.

It will let you determine what gets transmitted by the Keyboard (versus what is received by the tone generator).

If I turn off keyboard control it doesn't send any notes to the synth, so it is able to not send notes but I can only get an all or nothing solution.

KBD CTRL icon links the Part slot so they are all receiving instructions from your keys (and controllers).

When you are setup properly the Part slots that are playing will have the KBD CTRL icon active (green). So if your goal is to play internal and external slots simultaneously, the KBD CTRL on each will need to be active (green).

Activate Zone Master
Press [UTILITY] > “Settings” > “Advanced” > set the “Zone Master” switch On.
This makes the Master Keyboard Control function globally available. This adds two pages of parameters to each and every Performance PART in your instrument. These two pages are “Zone Settings” and “Zone Transmit”

EXTRA CREDIT
Step-by-step:
Press [UTILITY]
Touch “Settings” > “Advanced” > Set the “Zone Master” = On

From the Performance [HOME] screen — let’s create a Zone/Part slot to control your external synth.
Press [CATEGORY]
Set “Bank/Favorite” = All
Set “Attribute” = All
Touch “Init” > “Init Normal (AWM2)”
Press [ENTER

Touch Part 1 in the screen to *select* it.
Press [EDIT]
You should arrive at the “Edit - Part 1” level of the architecture
You want to see Part 1 - Common” parameters ( — You can tap the Part 1 and Common boxes in the lower left corner of the screen when you need to navigate...
Touch “Part Settings” > “Zone Settings”

Turn the “Zone Switch” = On

You do not want to use this Zone for internal MODX Parts so set the “Int SW” = Off
In the “Transmit Ch” box set it to ON by selecting the MIDI Channel you want to use to communicate with the external synth
Press [ENTER]

Here you can set the NOTE LIMIT range for your external synth
If you wish to send a Bank Select, a Program Change, a Volume Setting, or a Pan position setting, leave the four option boxes ON (green)
If you do not need any of these, set the ones you are not going to use to OFF.

The MIDI SEND box in the lower right corner makes the items you are sending from this screen, “live” - typically these parameters will be output via MIDI when you recall a Performance containing this data, but if you wish to send a live message to the external synth (say make it louder) with the MIDI SEND active (green) the “MIDI VOLUME” parameter on this screen is “live”.

In the second column, tap “Zone Transmit”.
Here you can determine which of the MODX’s physical controllers are going to be output from this Zone slot…
Green is ON (active); Grey is OFF (inactive)
You may, for example, wish to defeat the Sustain Pedal, if the Zone slot is going to control a Bass in a Piano/Bass split…

Finishing touches:
select PART 1
Touch “Part Settings” > “ General” > on the top line set a “Part Category Main”, a “Part Category Sub”
and give this Part/Zone a Name that will help you recall this whenever you want to use this setup for the external synth

Press the upper [COMMON] button
Tap “General”
Tap the “Performance Name” box
Give this entire Performance a Name… something that lets you know exactly what this is (include “Ext” so you know it is for external use)

Concept - you have setup a Part/Zone slot in a New Performance that will recall a specific sound on your external synth. Or you can skip setting a specific BankSelect/ProgramChange — and simply recall this configuration anytime you wish to use the MODX as a controller for the external synth. A single Performance can hold multiple setups for your external devices, by naming and storing them this allows you to recall them as easily as you would any internal programs. For example, you could store several setups in the single MODX Performance… not necessarily for simultaneous play, but like a GALLERY Factory Program, that has several different versions of a particular sound… use it like a storage bin… you can have one for each external synth. When you need a particular one, you can grab it via the Search function.

You can Merge this (Ext) Performance with any Performance with a slot available… this will allow you to add your external synth to any MODX Performance as easily as you add an internal sound.

If you are exclusively using it for Master Control functions you can recall this anytime you wish to communicate with the external device.

Hope that helps.

Extra Credit - important concept for using Zones
When you use [CATEGORY] search to *replace* an existing Part, you can mark the option that copies the “Zone” Settings from one Performance to another. Remember: you are substituting an external device for one of the internal Parts. So an internal program must initially occupy the Part slot, then you disconnect the internal sound with the “Int SW” (Internal Switch) = Off.
When you turn the Internal Switch Off, you are free to Transmit exclusively from that slot.

If you run the audio L/R output of your external synth to the A/D Inputs of the MODX, your journey to the MODX side will be complete… the external synth now has access to 2 Insertion Effects of its own, access via Send to the Reverb and Variation Effects, as well as running through the Master FX and EQ. Additionally, since the A/D In has access to Super Knob assignment, you can treat your external synth the same as you would an internal Part. You can morph to it with the Super Knob (using an FC7 pedal allows hands-free Super Knob control).

Let us know.

That was it, Thank you so much. I didn't realize that the zone key scale settings were their own thing and not linked to the "normal" one shown on the parts. Once changed in the zone settings it is working perfectly.

For your extra credit task, I am taking it one step further. I am setting up a patch bay and the AD I/O will be connected to it, so I will be able to easily patch any one of 16 synths to the A/D input. The patchbays arrive next week.

That was it, Thank you so much. I didn't realize that the zone key scale settings were their own thing and not linked to the "normal" one shown on the parts. Once changed in the zone settings it is working perfectly.

When you see the Part Note Limit ranges, think Tone Generator receiving. When you are in the Zone Settings, the Note Limit ranges are dealing with the Keyboard transmitting.

For your extra credit task, I am taking it one step further. I am setting up a patch bay and the AD I/O will be connected to it, so I will be able to easily patch any one of 16 synths to the A/D input. The patchbays arrive next week.

Sounds interesting. Let us know how it works out.