The Modulation Matrix¶
The modulation matrix is the main focus of Reducktion’s modulation system and is located in the lower panel page accessed by the MOD link:
The matrix presents 12 ‘slots’ in which modulations can be defined. A modulation consists of a source, a target and a modulation amount. Each slot contains a source selection menu on the left, a target selection menu on the right and a central parameter display for controlling the modulation amount.
A modulation source provides a value to be applied to a modulation target. Examples include envelopes, LFOs and note velocity. Modulation sources can produce modulation values from -100 to + 100 though in most cases they are limited to a subset of this covering a total range of no more than 100. For example LFOs provide output from -50 to +50, and envelopes from 0 to +100.
Modulation sources are either bipolar, where the values generated vary from positive to negative about 0, or unipolar where the value changes between 0 and a positive of negative limit. LFOs are by default bipolar but can be made unipolar using an offset of +/- 100. Envelopes are an example of a unipolar source.
Modulation targets represent synthesizer parameters to be controlled by modulation sources. They receive modulation inputs in the range -100 to +100 though in most cases the practical range will be less than this. For example volume targets do not recognize negative values and accept input from 0 to +100.
For each of the available modulation slots the output of each assigned source is sent to the assigned target. The actual modulation value applied to the target is determined by the modulation amount.
The modulation amount is a multiplier between -100 and +100 and represents the percentage of the modulation source applied to the target. By default the amount is 0 so no modulation is applied. Setting an amount of +100 causes all of the source value to be applied to the target. Similarly -100 applies all of the source to the target but with the opposite polarity. This is relevant for envelopes and LFOs where the output can be inverted.
Modulation targets may be modulated by multiple sources. The actual value applied to the target will be the sum of all the sources (limited to a maximum of +100 and a minimum of -100.)
The modulation applied to the target will be in addition to the value already assigned to the parameter via the control panel.
Modulation Sources¶
The following modulation sources are available:
Pitch Bend - the current potion of the pitch bend controller in the range -100 to +100. Note: pitch bend is always applied to the pitch of notes played according to the setting in the control section. If the pitch bend modulation source is applied to note pitch it is in addition to that applied directly from the MIDI controller.
Mod Wheel - the current position of the mod wheel in the range 0 to +100.
Foot Pedal - the current value from a foot controller in the range 0 to +100.
Channel Pressure - the ‘aftertouch’ pressure value in the range 0 to +100. This affects all the notes currently being played.
Key Pressure - the ‘aftertouch’ pressure value in the range 0 to +100. This affects only the notes where aftertouch is being applied.
Expression - the value provided from a controller via MIDI CC 11 in the range 0 to +100.
Brightness - the value provided from a controller via MIDI CC 74 in the range 0 to +100.
Note On Vel - the velocity provided by the Note On message for the current note in the range 0 to +100.
Note Off Vel - the velocity provided by the Note Off message for the current note in the range 0 to +100.
Mod CC - the value provided from a controller via the MIDI CC value assigned to the corresponding Mod CC setting (accessible via the system menu.)
Envelope - the output of the ADSR envelopes in the range 0 to +100.
LFO - the output of the LFOs. By default this is in the range -50 to +50. This allows the LFO output to be applied symmetrical to a source such as pitch. Use the LFO offset value to shift the range up or down to address unipolar targets such as volume (0 to +100).
Constant - a constant value of +100. This allows any fixed modulation value to be applied to a target using the modulation amount control; the value applied is the same as the amount. Applying a fixed negative amount to a target can shift the output a unipolar modulator, for example an envelope, into negative values turning it into a bipolar modulator.
Alternate - a constant value of +100 or -100 alternating with each note played.
Unipolar Rnd - a random number generated for each new note in the range 0 to +100.
Bipolar Rnd - a random number generated for each new note in the range -50 to +50.
Seq Mod - a modulation value provided by the current step of the sequencer, from -100 to +100. This is 0 when the sequencer is not running.
Modulation Targets¶
The following modulation targets are available:
Osc Tune - the oscillator pitch in semitones. For each unit change in the source value the pitch will change by a semitone. The pitch can be changed continuously over its modulation range.
Osc Semi - the oscillator pitch in semitones. This is the same as Osc Tune except it can be changed only in semitone intervals.
Osc Fine - the oscillator pitch in cents. For each unit change in the source value the pitch will change by a cent.
Osc Pos - the currently selected waveform or pulse duty-cycle.
Osc Pan - the oscillator pan position.
Osc Vol - the oscillator volume.
Osc Mod - the modulation amount for the FM modulators.
Osc Ratio - the ratio for the FM modulators. Unlike the control knob, which is fixed to integral and half-integral modulation ratios, the modulation target allows ratios to be modulated over a continuous range.
Filter Cut - the filter cutoff frequency.
Filter Res - the filter resonance level.
Noise Vol - the noise generator volume.
Noise Pan - the noise generator pan position.
LFO Rate - the LFO rate.
Env Attack - the envelope attack parameter.
Env Decay - the envelope decay parameter.
Env Sustain - the envelope sustain parameter.
Env Release - the envelope release parameter.
Mod Amount - the modulation amount for each of the 12 modulation slots. This allows the modulation amount of a given slot to be controlled by a second modulation source in another slot. For example, if slot 1 contains an LFO to filter cutoff assignment, a second slot can be used to assign the mod wheel to mod amount 1. In this way the mod wheel can control the amount of modulation applied to the filter. In this case set the LFO modulation amount to +100 and use the mod amount in slot 2 to control the maximum modulation level.