Obviously, most of the modulation-matrix parameters are set to zero by default, but there are two exceptions: MIDI Pitch-bend messages normally adjust pitch over a range of ☒ semitones, and MIDI Mod Wheel messages control the LFO pitch modulation amount to a small degree.īear in mind that MIDI Pitch-bend messages are different to Continuous Controller messages - Pitch-bend messages can have both positive and negative values, where Continuous Controller messages have only positive values. All six modulation destinations can be seen in Figure 1, which shows how MIDI Mod Wheel messages are routed to them using the six relevant XG parameters.Ī complete list of all the modulation-matrix parameters, along with their proper XG-format names and hexadecimal SysEx messages, is given in the 'Modulation Matrix Parameters' box for reference purposes, although all these messages can also be found in Yamaha's XG MIDI specification document mentioned in the first article of this series. The MIDI control sources can also modulate the degree to which the single LFO affects any or all of pitch, filter cutoff, and amplifier level, although here you can only make a positive-polarity setting. All of these three modulation destinations can be modulated with positive or negative polarity, so the filter can close or open as the mod wheel is raised, for instance. The six possible modulation routings for MIDI Mod Wheel messages.Īny of these modulation sources can control pitch, over a range of up to 24 semitones (two octaves) filter cutoff, starting from the main cutoff setting and amplifier level, starting at the main volume setting. The two Assignable Controller sources are MIDI Continuous Controllers, the numbers of which can be set using the hexadecimal MIDI SysEx strings F0 43 10 4C 08 mm 59 xx F7 and F0 43 10 4C 08 mm 60 xx F7 respectively, where 'mm' is the multitimbral part and 'xx' the desired MIDI Continuous Controller number.įigure 1. Some of the simplest XG modules may not recognise anything more than MIDI Mod Wheel and Pitch-bend messages (and I'll mostly be using those controllers for my examples in this article), but most of the studio units I've encountered will recognise all of them.
The six MIDI control sources which can feed the matrix are Mod Wheel, Pitch-bend, Channel Aftertouch, Polyphonic Aftertouch, Assignable Controller 1, and Assignable Controller 2.
However, because only a few (if any) of these parameters are actually accessible from the front panels of most of the hardware XG modules, MIDI SysEx messages are pretty much the only way to take full advantage of the power available. The modulation possibilities available within the XG format are remarkably flexible: six MIDI message types can feed the matrix, and each of these can be routed to any or all of six destinations in the voice architecture, with individual modulation amount control - that makes 36 parameters in total.
A Closer Look At The XG Modulation Matrix Therefore, in this final instalment of Yamaha XG programming tips, I'm going to look at how you get around this using the more advanced modulation facilities tucked away in the XG MIDI specification. One problem with layering voices, though, is that the normal MIDI controllers for pitch-bend, filter cutoff, and volume control adjust all parts on the same MIDI channel in the same way. In Part 2 I looked at how you can unlock the sound-design potential of your XG sound source by layering voices.
In the final instalment of our series of XG programming tips, we take a look at how the advanced modulation parameters can bring your layered sounds to life.