Following up on part 1 of this topic, controlling multiple synths that are being used as one involves setting up Digital Performer to output a MIDI track to more than one port/channel, and enabling the Multi-Record option in DP to specify what MIDI input device gets used for a specific MIDI track.
MIDI tracks in Digital Performer default to having only one MIDI output port/channel. If you want to use one track to control multiple synths, you will need to create a Device Group. Device Groups are combinations of MIDI outputs. You create Device Groups from the MIDI output section of a MIDI track in DP.
First, make sure that you are properly set up in Reason. Each synth should have its own MIDI channel assignment in the Adv MIDI Control section of the Hardware Interface. It is assumed that you already have setup DP for interapplication MIDI.
Create a device group by choosing the output of a MIDI track and selecting New Device Group.
In the Device Group edit window you can assign as many outputs to your device group as are defined in your Core MIDI setup. Click on the triangle below Device Group 1 and you get the MIDI output assignment popup menu. You can rename the device group by option-clicking on the name. When you’re done assigning outputs, close the edit window.
Note that if you want to edit a device group (add or subtract outputs), you need to navigate to the window via the Studio | MIDI Device Groups menu command. You can also create device groups from scratch through this command. From a track, you only have the option of creating new device groups. You can still edit old ones through the track popup, but a new device group will be created and selected for your track.
Once you’ve created a device group to control multiple synths in Reason, you’ll encounter an interesting problem. If your track with the device group is record-enabled in DP, moving any slider or knob in Reason for any of the grouped synths will change the same parameter on all the other grouped synths. For example, say you have three Subractor synths grouped in DP. Moving the Attack time of the Amplitude Envelope on any of the synths will move all the Attack time sliders of all the Amplitude envelopes on the other synths. This happens because moving one of the sliders in Reason causes a MIDI message to be sent from Reason to any application or device that is listening to MIDI messages. In DP, any record enabled track is listening to all MIDI input from any device/app on any channel.
To correct this problem, you need to enable Multi Record in DP (Studio | Multi Record). This allows you to record more than one MIDI track at a time. More importantly, it allows you to set the MIDI input for each record enabled track. We probably won’t be recording to more than MIDI track at a time, but being able to set the MIDI input to a record enabled track with a device group allows us to specify what device the track will listen to (and echo to its output device group). Choose the Korg Kontrol49 Port 2 (or Port A) device, any MIDI channel for your input. Now DP will ignore the changes you make to the front panels in Reason.