In our last post about using the Reason Rack plugin in your DAW, we provided a general overview and quick start guide. If you’re new to the Rack plugin and haven’t read that article yet, we highly recommend checking it out. If you’re ready for the next steps, this article will take a closer look at how signal routing works, which is one of the most important and inspiring aspects of the Rack. Without further ado, let’s plug some stuff in!
Routing overview
There are three main types of signals to be aware of when it comes to routing in the Rack. They are MIDI, audio, and CV (control voltage). Keep in mind that this is not the kind of CV that you can send out to external hardware modular synths, unless you send it out of the Rack plugin as a MIDI signal and then to a MIDI-to-CV converter and/or an appropriate DC-coupled audio interface. We’ll cover this in more detail in the next article of this series.
Audio and CV signals are routed in the Rack with virtual cables, usually on the rear panel, which you can see by hitting the Tab key or by clicking “Flip Rack” in the upper right section of the plugin. MIDI signals are not usually routed using cables.
Some devices have their own internal routing structure that will eventually want to explore. One example is the synthesizer device Complex-1, which gives you a detailed emulation of the routing structure of modular synthesizers, allowing you to do most of the routing on the front panel. However, in this article we’ll be looking at how signals are routed throughout the Rack generally. The routing system allows you to build effects chains, modulate the parameters of your devices, route control signals to external MIDI CCs, and more. We’ll start with MIDI.
MIDI routing
Unlike audio and CV, MIDI signals are not routed with virtual cables. The Rack plugin automatically receives and routes MIDI from whatever source is sending it to the host track in your DAW, whether that is a MIDI keyboard, your DAW’s piano roll, or a sequencer. The exception is the effect version, which will not receive MIDI if another plugin is placed before it in the signal chain of the track in your DAW.
By default, any MIDI sent to the Rack is received by all devices inside it. For more control, you can place devices inside a Combinator and use its Receive Notes settings to determine which ones respond, as well as create key or velocity splits. We’ll explain more in the next article in this series.
If you need fully independent MIDI sequencing and control for each instrument, it’s often easiest to load separate instances of the Rack plugin to your DAW project. Alternatively, you can use Player devices to sequence multiple instruments within one Rack and route their audio to separate outputs, though the number of outputs per plugin instance is limited. We’ll cover this in the next section of this article.
When loading a Player into the Rack plugin, a MIDI Out device is automatically added at the end. This allows the Rack plugin to send MIDI to any track in your DAW, or even to a hardware device if you have the appropriate MIDI/audio interface. This includes routing CV from Reason to MIDI CC values for modulating external MIDI-equipped devices. You can also add the MIDI Out device manually. It can be found in the Instruments section of the device browser, and you can learn more about it here.
There are a few things to keep in mind about MIDI and the Rack plugin:
- If you want to use the Rack as a MIDI sequencer for external plugins or instruments, we recommend using the VST3 version, since AU plugins do not natively output MIDI.
- If you add a Player device before an Instrument device, any MIDI sent to the Rack plugin will be received by the Player, not the Instrument.
- If you want to control parameters in the Rack with an external controller, you can map or expose those parameters through your DAW’s MIDI mapping system, just as you would with other plugins. The exact process will vary depending on your DAW.
Finally, some Rack devices include specifications that determine which MIDI notes trigger internal samples or sounds. To check a Rack device’s MIDI specs, refer to its dedicated section of the Reason manual.
Audio routing
At the very top of the Rack, you’ll find the I/O device, which is one of your biggest allies when it comes to audio routing. The I/O device is where audio routing between the Rack and your DAW is displayed and managed. It gives you visibility and control over how audio enters the Rack (when using the effect version of the plugin) and how it exits back to your DAW.
The Rack can send up to 32 independent audio channels (16 stereo pairs) from a single instance. When using the effect version of the plugin, you also gain access to a dedicated sidechain input. You can learn more about sidechain routing here.
How you set up multiple outputs from the Rack to your DAW will depend on which DAW you’re using, but we recommend trying it out with a multi-channel device like Redrum Drum Computer. By routing each channel in the instrument to an output in the I/O device and configuring tracks in your DAW to receive those outputs, you can process them separately. Note that you’ll need to disable the “To Main” option for each set of channels that you want to route out to an independent track in your DAW.
Within the Rack, routing can be done automatically or manually. When you add a device to your Rack (by double-clicking or dragging it), the device’s audio is routed automatically. If you hold down Shift while doing this, the audio is not routed, and you can set up the routing manually.
Flipping the Rack allows you to not only get a look at how audio is being routed, but to manually change routings by dragging the Rack’s virtual cables (you can learn more about manual routing here). This is great for getting creative with how you build effects chains, develop layered ensemble sounds, and more.
Keep in mind that if you want to bypass or turn off an Effect device, you can use the Bypass/On/Off switch in the top left of the device’s front panel. This is set to On by default, but setting it to Bypass allows audio to pass through unaffected. Setting it to Off will silence it completely, with no sound passing through.
CV routing
In addition to audio and MIDI, the Reason Rack plugin also lets you work with CV (control voltage) signals. These signals don’t carry sound. Instead, they are used to control and modulate the parameters of your devices, which opens up a huge range of creative possibilities.
If you flip the Rack around, you’ll notice that CV connections use smaller jacks than audio cables. These connections can be used to send modulation from one device to another. For example, you might use an LFO to modulate a filter cutoff, or an envelope to control amplitude on a different device. Gate signals are also part of this system and are typically used to trigger events like notes or envelopes.
Note that you can often use modulation sources from within an instrument as a CV source to send to other devices, even if it doesn’t appear with its own dedicated output on the rear panel. This is usually done by routing a source like an envelope or an LFO to one of the CV outputs using the instrument’s modulation matrix. In the example above, one of Europa’s envelopes is routed to CV1 Out (indicated by the white box), which is then routed to control the Dirt level in the Pulveriser Demolition effect device via the back panel.
A CV input will also often include a Trim knob, which controls how strongly the incoming signal affects the parameter. Turning it up increases the modulation depth, while turning it down reduces or disables it. Because CV is not limited to traditional signal flow, it’s one of the most powerful ways to get creative in the Rack. You can use it to build evolving sounds, complex modulation chains, or even unconventional setups where one device controls multiple others at once.
Advanced routing
There’s a lot more to routing in the Rack than classic effects chains and sequencing. A number of devices are available to help you get extra creative with audio and CV signals.
Spider Audio Merger & Splitter lets you combine multiple audio sources into one signal or split a single source into several paths. This is useful for subgrouping sounds, applying shared processing, or creating multiple variations of the same signal for more complex mixes.
Spider CV Merger & Splitter handles control signals instead of audio. It can distribute Note CV and Gate to multiple devices, combine modulation sources into a single control signal, or use inverted outputs to create opposing or crossfading modulation.
Combinator acts as a container for multiple devices and their internal routing. It allows you to build layered instruments, key and velocity splits, or complex effect chains, all of which can be saved and recalled as a single patch.
Pulsar, as we mentioned earlier, is a dual LFO device designed for modulation. Its two LFOs can modulate other devices or each other, and can operate at both low and audio rates, making it useful for everything from subtle movement to more complex, evolving modulation setups.
Mixer 14:2 gives you a central place to balance and shape multiple audio sources, but it can also play an important routing role. In addition to channel level, pan, EQ, and AUX sends, it lets you chain multiple mixers together, route shared send effects, and use CV to control channel or master levels, making it useful for building larger and more flexible setups.
One cable at a time
As you can see, the possibilities with routing in the Rack are pretty vast. If it feels a bit intimidating at first, don’t worry! It’ll all feel very intuitive the more you try out the basics. Next up in this series, we’ll be running through a few practical examples that will help you get a better handle on everything and make the Rack plugin one of the most powerful additions to your DAW. In the meantime, keep patching and playing!
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