4. Parameter Automation and External Control
Using MIDI, you can record parameter movements and recall them with the sequence. You can also control parameters using external MIDI devices.
The usage of MIDI messages depends on the host applications. Exciton is designed for the optimal control with Cubase VST and Logic Audio.
As the MIDI message usage differs among host applications, it is unknown if Exciton can be well controlled by a host application other than Cubase and Logic. But most host applications support MIDI control messages. If you uses another host application, it is worth trying with control messages. Refer to "Cubase VST" column of 5. MIDI Control Messages for detail.
4.1. Automation and External Control on Cubase VST
You can record movements of knobs and switches using MIDI system exclusive messages on Cubase VST. Parameters can be controlled using MIDI control change messages.
Following explanation is specific for using with Cubase VST 5.1.
The usage of MIDI messages differs among host applications. It may also differ among different versions of the same application. Following contents are checked with Cubase VST 5.1. But the specifications may be changed for the future versions of Cubase.
4.1.1. Automation with System Exclusive Messages
Cubase can record movements of knobs and switches with system exclusive messages. If you change knobs and switches while recording the MIDI sequence, the changes are recorded into the MIDI sequence as special exclusive messages.
This is a specific function for Cubase (other applications does not support it). Using this method, select Options - MIDI Setup - Filtering... from the pulldown menu and enable system exclusive messages on the MIDI Filter dialog box (it is disabled as default).
4.1.2. Automation and External Control with Control Messages
Using with Cubase, almost all parameters (without number of voices and MIDI input channel) can be controlled with MIDI control change messages. You can also operate Exciton with an external MIDI device using control messages.
Exciton can be operated with control changes messages. All parameters (without number of voices and MIDI input channel) are mapped to each control numbers. Please refer to 5. MIDI Control Change Messages for detail.
It is also recommended to check for MIDI Filter dialog if control change messages are filtered.
Number of voices and MIDI input channel cannot be changed by control change messages. It is a safety for avoiding wrong behaviors when unexpected MIDI messages are received.
- If the number of voices is set to the maximum on unison mode, it consumes CPU too much and the system may get unstable.
- If the MIDI input channel is changed to an unexpected value, it gets out of control.
Using control change messages, parameters can be controlled with external MIDI devices. For example, if you have a keyboard or other MIDI controller (knobs, faders, etc.) and can send breath control (#3) messages, the filter cutoff frequency can be operated with it. Assigning the MIDI output to Exciton and sending breath control messages from the MIDI controller changes the cutoff frequency of Exciton.
If the MIDI device outputs control messages with a fixed control number and the number does not match to Exciton's parameter, you can use the controller map function of Cubase. Selecting Options - MIDI Setup - System... from the menu and editing control number mappings on MIDI System Setup dialog, control change messages are converted to an appropriate control number by Cubase.
Several parameters are mapped to two control numbers (for Logic). They can be controlled with both numbers (ex. #2 and #54 for the filter cutoff frequency).
4.1.3. Differences between Two Methods
Comparing the control using system exclusive messages and using control change messages, there are advantages and disadvantages for both methods. Differences are summarized as follows.
System Exclusive | Control Change | |
---|---|---|
Recording Mouse Operations | Yes | No |
Control with External Devices | No | Yes |
Edit with the Control Editor | No | Yes |
Edit with the List Editor | Difficult[1] | Yes |
[1]It is possible to display and edit raw system exclusive messages with the list editor of Cubase. But Cubase uses a special format for parameter automation and its specification is not published (binary floating point numbers may be used). If you are a hacker, you can examine a format. But it is definitely not recommended for general musicians.
As a result, using control messages may be a little more convenient. When making a sound program, using a mouse is easier. After you save a sound program, you can record parameter movements with control messages on the control editor.
4.2. Automation and External Control on Logic Audio
Using with Logic Audio, major parameters can be controlled. They can be also controlled with external MIDI output devices. As the usage of control messages for Logic is different from Cubase (and other applications), control numbers are different. Please refer to 5. MIDI Control Messages for detail.
Following explanation is specific for using with Logic Audio 4.8.
The usage of MIDI messages differs among host applications. It may also differ among different versions of the same application. Following contents are checked with Logic Audio 4.8. But the specifications may be changed for the future versions of Logic.
Logic uses control change messages for the audio channel controls. For example, control number 3 is used for solo on/off, #7-10 are used for volume, balance, mute and pan respectively. These messages are not sent to the plugin and used for audio controls by Logic.
Messages above 64 are allocated for plugin controls. If no other effect insert is used, these messages (#65-127) are converted to the parameter value and sent to the instrument plugin. If another effect insert is used, #65-79 are used for the instrument plugin and #80-127 are used for inserts. Control change messages are multiplexed to the plugins on the audio channels by control numbers.
#64 (sustain pedal) is displayed as a instrument control (Exciton#1) on Logic. But for audio instrument channels, it is used as a normal sustain pedal message and sent to the instrument. (If #64 message were converted to a parameter value, you would not be able to use a sustain pedal).
Control change messages above 64 are converted to parameter values and sent to plugins. On the other hands, if you drag knobs or click switches and change parameters, the changes are converted to control change messages by Logic. You can record parameter movements with mouse operations for parameters mapped above #64.
As a result, if you do not use plugin inserts for the audio instrument, most parameters can be controlled. But if you use inserts, only a few parameters are controllable. To control more parameters, Exciton maps frequently used parameters to the unused area of number below 64. The mapping of available control numbers and parameters are listed on 5. MIDI Control Messages.
#0(bank select) and #1(modulation) are also unused by Logic. But they are not mapped to Exciton's parameters.
- #0 is reserved for future expansion (preset sounds to be added).
- #1 is sent by the sequencer as a reset message and cannot be used for the parameter control.
Using Logic, the following parameters cannot be controlled with MIDI.
- OSC1 Wave Type
- Unison/Legato
- Master Tune
- Output Volume
For output volume, you can use the Logic's channel volume instead (#7).
If an external MIDI controller you use outputs control change messages with a fixed control number, you can use Logic's function. For example, you can use a Transformer object on the Environment window. Logic has very powerful MIDI processing functions and almost everything you want for MIDI is possible. Please refer the manual or other books for Logic.
Parameters mapped to the unused area below #64 are not recognized as plugin parameters by Logic. As a result, MIDI messages are not sent if you move knobs or switches.
Furthermore, #120-127 cannot be used for realtime controls with the external MIDI devices. But it is possible to use them for the parameter automation with prerecorded sequences.
Above are summarized as follows.
Control Number | Recording Mouse Operations | Control with External Devices | Use with Effect Inserts |
---|---|---|---|
2, 4-6, 11-24 | No | Yes | Yes |
65-79 | Yes | Yes | Yes |
80-119 | Yes | Yes | No |
120-127 | Yes | No | No |