MSEG
The MSEG module provides a sophisticated Multiple Segment Envelope Generator that allows complex modulation envelopes to be created and edited.
Any number of breakpoints can be added to an envelope. The envelope segments linking these breakpoints can be linear or curved. A Sync function allows envelopes to be anchored to a grid derived from the host application’s tempo to create elaborate rhythmic patterns.
The MSEG display shows a graph of the envelope generator’s output. The ruler along the top shows the time, calibrated in seconds (or in beats when Sync is activated — see below). The envelope appears as series of small squares (breakpoints) joined by lines/curves representing the different envelope segments. Beginning in version 1.12, a Play Cursor scrolls across the display, tracking the progress of the envelope relative to the most recently played note.
Editing MSEG envelopes
Envelopes are created and edited in two basic ways: by adding, moving or removing breakpoints, and by adjusting the curve of the envelope segments between breakpoints.
- To move a breakpoint, simply click and drag it.
- To move a several adjacent breakpoints together as a group, first drag around the breakpoints to select them all. Then click and drag any breakpoint in the group.
- To add a breakpoint, right-click (command-click) at the place where you want the new breakpoint to appear.
- To remove a breakpoint, right-click (command-click) it.
A breakpoint’s x value (time position) and y value (level) are reported together in the parameter value display when you click the breakpoint, and the displayed values update as you drag the breakpoint.
Each envelope segment has a ‘handle’ (a square box, slightly smaller than a breakpoint) halfway along its length, which is used to adjust the curvature of the segment.
Dragging the handle upwards causes the segment to become progressively more convex; dragging it downwards causes the segment to become progressively more concave. Convex, ‘flat’ and concave envelope segments produce characteristically different effects.
Edit modes
The Mode pop-up menu allows you to choose from one of four editing modes that determine how the envelope will react to being edited.
- ‘Normal’. One breakpoint at a time can be moved, by clicking and dragging. The surrounding points remain stationary.
- ‘Slide’. Dragging a breakpoint also moves all subsequent points in the envelope, so that the relative distance between these points is preserved.
- ‘Stretch’. Dragging a breakpoint to the left compresses earlier points and stretches later points, while dragging it to the right stretches earlier points and compresses later points. In either case the total length of the envelope is preserved.
Sync
When the Sync button is activated, the time ruler along the top of the MSEG display is recalibrated in beats (calculated from the host application’s current tempo) and a grid of vertical lines (spaced at quarter-beat intervals, or less frequently when zoomed out) is superimposed. Breakpoints ‘snap’ to these grid lines when dragged or created, making it easy to create precisely-aligned rhythmic envelopes.
Loop markers
Two pale blue vertical lines also appear in the MSEG display, each with a small rectangular ‘handle’. These are the envelope loop markers.
Note: if ‘None’ is selected in the Loop pop-up menu (see below) the envelope has no loop, and the loop markers are consequently not displayed.
The marker with the higher, leftward handle controls the loop start point. The marker with the lower, rightward handle controls the loop end point.
The loop markers are moved by simply dragging them in the desired direction. For obvious reasons, the loop start marker cannot be moved to the left of the loop end marker, and the loop end marker cannot be moved to the right of the loop start marker. Loop markers always snap to the nearest breakpoint.
The loop modes, accessible from the Loop pop-up menu, are as follows:
- ‘None’. Looping is disabled.
- ‘Continuous’. The looped section plays continuously in a forward direction while a note is held, and goes on looping after the note is released.
- ‘Sustain’. The loop section is played while a note is held. When the note is released the remainder of the envelope plays.
- ‘Forward/Back’. Like ‘Continuous’ except that the looped section is played alternately forwards and backwards.
Other controls and parameters
- SnapY quantizes the breakpoint levels (or y values), limiting them to exact fractions of the available range. For instance, a SnapY setting of ‘1/3’ means that breakpoint levels will snap to the values 0, 1/3, 2/3, and 1 when dragged. A SnapY setting of ‘None’ turns quantization off and allows you to set breakpoint levels freely.
Note that the SnapY setting does not move existing breakpoint levels into alignment with quantized positions; it only affects how breakpoints respond when created or dragged.
- Current MSEG field. Alchemy provides up to 16 MSEGs (two by default), and you can access each MSEG’s control panel by selecting its number in the Current MSEG field.
- FILE. Clicking the FILE button opens a pop-up menu from which you can Load/Save MSEG presets from/to files (*.mse). A collection of useful presets is included (in the ‘Libraries’ folder within Alchemy’s data directory). You can also Copy and Paste settings between MSEGs, or choose Clear to initialise the module.
- TRIGGER. When the TRIGGER button is activated, the envelope re-triggers (starts again from the beginning) with each new note. With TRIGGER deactivated, the envelope is always running, even before the first note-on; it re-triggers on the first note of each legato group and continues its progress for subsequent notes of the group.
Example: Modulating pitch
1. First, initialise the preset (by clicking FILE in Alchemy’s title bar, and choosing ‘Clear’).
2. In the Master section, click the Coarse-Tune knob, and assign ‘MSEG 1’ as its modulator.
3. In the modulation rack, set MSEG 1’s Depth control to 24 semis.
4. If the MSEG module’s control panel is not already in view, click the MSEG button at the top of the Modulation section to access it. From the SnapY pop-up menu, choose ‘1/24’.
Now an MSEG envelope can be used to control Alchemy’s pitch in semitone increments, over a two-octave (i.e. 24-semitone) range.