When recording music on your computer, you have a lot of great software to choose from. I’ve spent quality time with several different recording apps, including Steinberg Cubase, Image-Line FL Studio, and Ableton Live — but for me, Propellerhead Reason hits a sweet spot. It has limitations, but it also has some unique strengths.

Oddly, one of its main limitations is also one of its great strengths. Unlike the typical DAW (digital audio workstation), Reason will not host third-party plug-ins in the industry-wide VST format.

If your go-to bass, piano, or compressor is a VST, you would have to use Reason side-by-side with a more conventional DAW via the ReWire protocol. The workflow would be awkward.

Instead, Reason’s third-party plug-ins are in a format called Rack Extensions. Rack Extensions work only with Reason, not with any other host program.

That’s the bad news. The good news is Rack Extensions (RE’s for short) are typically less expensive than VST plug-ins. Installation and compatibility hassles are almost unheard-of, because Propellerhead gives RE developers strict guidelines. You have hundreds of clever devices to choose from, and while many are meat-and-potatoes plug-ins such as synthesizers and reverbs, others do exotic tricks that would be difficult or impossible to manage in any other recording platform. RE’s all use a standardized user interface, which makes them easy to learn and use. Best of all, you can download any RE as a 30-day trial from the Propellerhead Shop, without paying a cent. In fact, you can download Reason itself ($399) as a 30-day trial and then grab a bunch of RE trial downloads too.

With so many RE’s to choose from, finding the most useful or great-sounding items on the Shop page can seem daunting. I’ve tried out dozens of RE’s, and purchased more than a few of them. In this article we’ll take a look at a few of the RE’s I feel are the most useful. My personal list of favorites may not be the same as yours. If you need vintage TR-808 or 909 percussion, the Quadelectra drum modules ($39 each) and System 9 sequencer ($49) would be strong candidates. If you’re performing live with Reason, the Buffre audio repeater ($85) from Peff or the Hamu control panel devices ($19 to $29) might be ideal. If you’re concerned with mastering, the Splex multiband compressor from DlogB ($29) or the ReQ131 graphic equalizer from Lab:One Recordings ($29) may be a great choice.

Unfortunately, we don’t have space for a full explanation of Reason’s features. If you’re not familiar with Reason, download the free trial version, lock yourself in your music room for a week or two, and dig in to the owner’s manual, which (groan!) is upwards of a thousand pages long. Or do yourself a favor and swing over to YouTube, where Propellerhead has more than 50 tutorial videos. Even in the absence of RE plug-ins, Reason ships with a powerful suite of synthesizers, effects, and audio recording tools. But until you start adding a few RE’s, you’ll be missing out on a lot of music-making power. So let’s see what the Shop has to offer.


Before you download a single Rack Extension, Reason supplies 22 effects processors — compression, reverb, chorus/flange/phaser, EQ, delay, a vocoder, amp models, a three-band rhythm-based gate, and pitch correction. But a mix needs some extra spice every now and then.



For processing drum sounds, either from an audio track or from a percussion synth, you just about can’t beat GSX. It splits the incoming signal into five frequency bands, which are processed independently. The crossover frequencies are not user-adjustable, one of its few shortcomings. Each band has its own attack/decay compression, a pattern for rhythm-based delays, and a variety of simple effects, such as ring modulator and LFO- modulated lowpass filter.

But you’re not limited to the onboard effects: Each band also has its own send/return insert jacks on the back panel, with which the audio can be handed off to any other Reason effect.

Four GSX presets are available at once, and you can switch among them by tapping a MIDI key, causing subtle or drastic changes in the sound. An external send can be active for one band in one preset, but not active in another preset. MIDI keys can produce a tape stop effect or a rhythmic stutter — and during the stutter, the pitch-bend wheel becomes active, allowing you to throw the stutter up or down.



Reason boasts two distortion devices on its own — Scream and Pulveriser. Both are great, but neither of them is a multiband effect. Tritone is more versatile. It splits the incoming signal into low, mid, and high bands (with user- adjustable crossover frequencies) and lets you apply any of 13 different distortion types to each band. Drive, blend, and asymmetry can be adjusted per band, and an envelope follower can be used to modulate the output level or blend of each band. The tone colors Tritone can produce are incredibly varied.



For radical delay processing, nothing tops Steerpike. This RE boasts six separate delay lines, which can be configured in various ways, such as series, parallel, and ping-pong. I’ve found its reverse delay algorithm quite musical, especially with percussion tracks. A dual LFO can modulate the delay times, with up to eight seconds of delay for each line. With the random waveform from the LFO, you can add an exotic underwater flavor to a synth pad sound. An envelope generator triggered by a rear-panel gate connection can shape the output level of each delay line, with a separate gate input for each line. Naturally, there are separate pan, level, and feedback controls for each line, and also a THD (harmonic distortion) knob for adding thickness.

In BBD mode, Steerpike emulates an old-school hardware delay line. The effective clock rate in this mode can be dropped down very low to add aliasing. Another key feature is the great freedom for setting the synchronized delay time, which can be in odd fractions of the beat such as 11/5. Extras include onboard EQ, an audio tap in/out jack for each line, and extensive rear-panel control inputs.


Reason’s own Thor, Malstrom, Subtractor, and its Kong percussion module will do an amazing variety of leads, basses, keys, and what- have-you. When you’re ready to add an RE synth, you can choose from modeled analog, FM or additive synthesis, sample playback, vintage keyboards, or various kinds of modeled sound generators. Here are a few of my favorites.



Need a guiro track, but your microphone fell in the bathtub? Republik is your friend. It houses 62 multisampled percussion instruments, mostly handheld, ranging from agogo to washboard. Small household items such as saucepan and spoons are also included. With its own room ambience processing as well as basic synth parameters, Republik is well set up for adding at least a modest imitation of real hand percussion to a mix.

In multisample mode, several related sounds are assigned to adjacent keys, so you can play a pattern that has a bit of variety. By switching from multisample to a solo sample layout, you can play melodically or use a jam jar sample as a layered attack transient with a synth sound.



For old-school analog synthesis, Antidote is brilliant. Bass, leads, pads, stylish arpeggio patterns straight from Berlin — it’s the real deal. A full bank of internal effects adds vital color to Antidote’s sound or can process external audio. The arpeggiator has rear- panel outputs for driving other instruments.

At first glance, with its standard lineup of dual oscillators, multimode filter, and ADSR envelopes, Antidote may look boring, but there’s more here than meets the eye.



In theory, SubBoomBass is all about bass tones and kick drum. The reality is far broader. A dozen of the 65 waveforms are sustained synth tones. With these, waveform symmetry and width modulation can add animation, and a multimode filter with vowel and comb modes gives more tone-shaping power. The bigger group of waves is sampled percussive attacks: kicks, toms, udo, surdo, orchestral bass drum, and so on. What’s especially nice is that the 16-step sequencer turns SubBoomBass into a capable rhythm device: You can fire a different oscillator waveform for each of the two oscillators on each step of the sequence. Sequence steps can either fire notes or be rests, so you have a nice kit of percussion sounds and a full bar of sixteenth-notes with which to dial up your own patterns.



What would an aggressive rock mix be without a Hammond organ screaming in the background? Revival is a lot more than just a Hammond-inspired drawbar organ, but its sound programming options are so deep and twisted that probably most of us will just load it up, choose an organ preset, and wail. It has a built-in Leslie simulator, preamp distortion, separate drawbar sections for the attack and release, and dual drawbar sections for layering or crossfading the main body of the tone. The modulations that can be switched on or off for each drawbar are limited and rather peculiar, but they add a lot of sound power that Hammond players have never dreamed of. Hammond-style parameters such as key click and on/off vibrato sit side-by-side with synth controls such as portamento and velocity response.


One of the features that makes Reason unique is that its instruments and effects are deployed in a realistic-looking virtual “rack.” By hitting the Tab key, you can flip the rack around and look at the back panels of your devices. Here you’ll find a variety of control signal inputs and outputs, which can be connected by clicking and dragging on-screen patch cords. In some sense, the patching possibilities make Reason a single gigantic modular synthesizer. By patching one device to another, you can create complex musical events and textures.

Reason’s own control signal sources are fairly basic; mainly a step sequencer and an arpeggiator. The synths have aux outputs for their LFOs and envelope generators, with which you can add external control of almost any parameter in any device. But that’s just the start of the fun.



Like Reason’s own Matrix step sequencer, Step Note Recorder is a monophonic 32-step device, but it has numerous extra features. It will do real-time recording from a MIDI keyboard, which is handy either for data entry or possibly in live performance. It gives you control of gate width per step, stutter, and repeat output per step, rests, slide, and a choice of direction types (alternating, reverse, and so on). By controlling the Offset parameter with a rear-panel input (perhaps from an LFO), you can rotate your sequence data forward and backward, producing chaotic patterns. If you need even deeper rhythmic madness, you might want to give Robotic Bean’s Euclid Rhythm Generator ($39) a spin. Step Note has no bank of pattern memories. I’ve been told that because of the extensive real-time control that Step Note provides, a bank of patterns would not be possible under Propellerhead’s developer guidelines. All is not lost, however: Robotic Bean also has a module called the Select CV Switch ($9), which can be switched among eight different inputs from a bank of Step Note modules.



Though it’s called a step sequencer, Korde is a hybrid sequencer/arpeggiator. It accepts up to eight-note chords played on the keyboard (or more likely chords you’ve recorded into a track) and distributes them in whatever pattern you like, with one note per step. It has eight simultaneous channels of note output, each with its own gate, note pitch, and two CV signals. What’s more, each of those eight channels has its own set of eight stored patterns.

Each triggered note has octave up/down transposition. Useful editing tools are available on the front panel. In addition to setting the length of the sequence for any voice in any pattern, you can set a rhythmic division for the whole row using fractional values from 2/1 up through odd values like 11/7 — yes, it’s polyrhythm city! Still not satisfied? On the back panel are eight inputs for note value overrides. Instead of using any given note in your held chord, your pattern can be mutated by the note output from something else. If your music uses arpeggios, Korde is a device you won’t want to miss.



Most of Reason’s synthesizers, despite their other heavy-hitting features, make do with basic ADSR envelope generators. (What’s up with that?) To tackle this limitation, you may want to check out Charlotte, a freestanding module that provides a nine-stage looping envelope with a programmable curvature per segment. The tricky bit is that Reason pretty much doesn’t provide a way to use a device like Charlotte polyphonically with a single synth. Instead, you’ll need to attach Charlotte to several synths, which could be assigned the same or different sounds. Having each new key you play produce a different sound is an exciting possibility that was first heard in Oberheim’s Xpander hardware synth in the mid-’80s.

Once you’ve set up this patch, you can send notes to Charlotte and it will distribute the notes to the various instruments. This type of patching takes a bit of thought, but the results are well worth it. Charlotte also has audio in and out, allowing it to be used as an envelope-controlled VCA. Another envelope generator RE, PSDN from Alien Seed Tech ($29), lacks Charlotte’s voice distribution feature, but provides control signal inputs for controlling its two envelopes in complex ways.