Mela – AUv3: Synth, FX, MIDI 4+

Everything is a Module
This update unifies several core concepts. A Mela preset is now powered by a root-level Stack module, containing Group modules as its submodules. In other words, the root-level lanes in a preset are Group modules arranged within this Stack.

Lane Improvements
- A lane can now be thought of as an instance of a Group module because that's exactly what it is.
- Lanes can now be toggled off or renamed just like other modules.
- Lanes were redesigned to be more compact.
- Lane headers now appear on the left, with titles aligned to module titles and an actions button.
- Tapping the title collapses the lane vertically, similar to modules.
- Up to 3 collapsed lanes can precede an expanded lane.
- If more than 3 collapsed lanes are consecutive, the next expanded lane appears below them.

Drag-and-Drop
- You now need to grab a module or lane by its header and hover it over a lane header or a module to insert it in front of it.
- The dimming effect was replaced with a dashed outline between modules/lanes to indicate the module/lane insertion location.
- Since lanes are modules of Group type, they can be dragged over any module to be inserted in front of it.
- A Group module can now become a lane by dragging and dropping on a lane header, a new lane will be inserted before it.
- If a non-Group module is dragged and dropped in front of a lane, a new lane is created before it with the module inserted.

Stack Module
- Introducing Stack, the first module that processes its submodules in parallel rather than in series, like sublanes.
- The Stack module feeds a copy of its input signals to all its submodules.
- The module's output signals depend on the Mode parameter, which has three states: Sum Audio, Merge MIDI, and Passthru.
- Sum Audio: Stack's output Audio, or the Audio components of the Poly signal, is the sum of the submodule output Audio and/or the Audio components of Poly signals.
- Sum Audio: If Stack's input and all submodule outputs are Poly signals, the module's output will also be Poly. Otherwise, it will be Audio.
- Sum Audio: The MIDI signal and non-Audio Poly signal components (unless collapsed) remain the same as Stack's input.
- Merge MIDI: Stack's output MIDI signal is a merge of the submodule output MIDI signals.
- Merge MIDI: The Audio and Pitch signals, or the Poly signal, remain the same as Stack's input.
- Passthru: The submodule outputs are ignored, and Stack's output signals are identical to its inputs.
- You may want to process multiple sublanes in parallel for more complex setups. To do this, simply stack Group modules.
- With the Stack module, you can create simple MIDI effects, such as converting notes into chords by stacking Transposer modules, or build complex sequencers by combining Group, Euclid, and others.
- You can also easily create layered synths or effects.
- Stack lets you view submodules individually or as an expanded horizontal stack.
- When viewed as a horizontal stack, unlike sublanes, vertical lines replace signal indicator arrows, indicating that the submodules are processed in parallel.
- Stack is part of Collection 4 and can be found under the Signal Router category.

Crossover Module
- The Crossover module splits the Audio signal into frequency bands using second-order crossover low- and high-pass filters.
- This makes it ideal for building custom multi-band processors, such as multi-band compressors or distortion effects.
- The module's crossover filters are designed to ensure a flat frequency response.
- To create a 2-band processor, route the same audio into two parallel instances, set one instance's Band parameter to Low and the other to High, and ensure both have the same cutoff frequency by entering identical numeric values.
- To create a 3-band processor, take the output of one of the instances and apply another crossover split, following the same approach.
- Crossover is a Mela Lab module and part of Collection 4.