There are few things more satisfying than a fat bass synth, and Reason is full of go-to sounds to bring huge low-end to your mix. But for those who like to dive in and tweak some knobs in search of the perfect sound, it can be even more gratifying to design your own bass from the ground up. This sound design tutorial will focus on how to make a bass patch in Reason with Subtractor, the beloved analog-modeling synth with a fat sound and a few tricks up its sleeve.

To get started making a Subtractor bass patch, first right-click anywhere on the instrument and select “reset device” to set all controls to their default state. Then set the polyphony to 1 to make your patch monophonic for a tight bass sound. At first, you’ll hear a very basic, no-frills sawtooth wave—don’t worry, you’ll be turning this humble patch into a thick, beastly bass in no time!


Subtractor’s sound starts at its two oscillators, which feature 30 different waveform options. Here, you can also adjust each oscillator’s octave, tuning, mix level, and more. These options can produce some pretty far-out tones, but simpler is often better for bass sounds. Try using a square or sawtooth wave with rich harmonics, supplemented by a rounder triangle or sine wave an octave below that for a thick, assertive tone. To change up your sound a bit, switch the phase mode to X or – and adjust the phase knob to create unique variations on each waveform.

Analog-Style Filters

Next come Subtractor’s analog-style filters, which shape your sound by subtracting certain frequencies (this is also where Subtractor gets its name). Low-pass filters are a great choice for bass patches, because they cut out the high-end to emphasize the low-end. Subtractor has two types of low-pass filters: LP12 gradually rolls off the highs, while LP24 has a steeper cutoff. The frequency and resonance controls fine-tune the sound, and the keyboard tracking control adjusts the filter when you play higher or lower notes. A second low-pass filter can be linked to the first for even more tonal possibilities.


By now you’ve quickly built a rich bass sound with plenty of analog character, but it may still sound a little static. This is where the envelope section comes in handy—envelopes shape your sound over time, from the initial attack of each note to the decay, sustain, and release time. The amp envelope uses these parameters to control volume, while the filter envelope affects the filter frequency instead. Combined, Subtractor’s envelopes can deliver anything from funky wah-wah-type sounds to slowly morphing swells.


Oscillator, filter, and envelope combinations offer a ton of possibilities, but the fun really begins when you modulate those parameters to add motion and expression to your sound. Subtractor’s two LFOs (low-frequency oscillators) can be used to rhythmically control parameters including oscillator pitch, phase, or filter frequency, which produces a dubstep-style wobble when synced to tempo.

The mod wheel can also be assigned to different parameters, including LFO speed. Finally, Subtractor’s velocity section allows you to control how the dynamics of your playing affect the sound.

And there you have it—all the sound design knowledge you need to get started making an analog bass patch with Subtractor. Once you’ve mastered the basics, these principles can be applied to many other Reason devices and Rack Extensions, opening the door to limitless possibilities.

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