Review: Eventide Fission

A whole new take on effects processing
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Fission is a dual multi-effects processor plug-in with a major twist. Thanks to Eventide’s new Structural Effects technology, it can separate the transient signal from the tonal signal of your audio, process each through separate effects, and then recombine them at the output. It’s like no other effects processor on the market, and it offers enormous creative possibilities.

Fission’s GUI is divided into three sections—Transient Effects, Structural Split, and Tonal Effects—each of which can be turned on and off independently. The Transient and Tonal Effects have separate Gain controls and Solo buttons, both of which are important, as you’ll see.

The Transient and Tonal sections have separate effects processors with multiple choices, though only one effect can be active at a time in each. Some effects types are available in both the Transient and Tonal menus, while others are specific to one or the other. The Transient section offers Delay, Tap Delay, Dynamics, Phaser, Reverb, and Gate + EQ, whereas the Tonal section provides Delay, Compressor, EQ, Chorus, Reverb, Tremolo, and a 3-voice pitch shifter.

Eventide Fission is a plug-in (AAX, AU, VST) that lets you separately manipulate the transient and tonal aspects of an audio signal.

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Eventide recommends that you start by using the Source Type slider or dropdown menu to select a source type that best matches the incoming audio in order to calibrate Fission’s algorithms.

As you listen to your audio play back, you can use the Focus slider to change the balance of transient to tonal information coming from the input. In use, this parameter (which isn’t explained well in the manual) can seem somewhat counterintuitive because, with a sound that contains both tonal and transient information, pushing it closer to Transient often yields a more tonal sound and vice versa.

The Smoothing parameter can be used to reduce the sharpness of transients, whereas the Transient Decay control increases their decay. A large waveform display provides a visual representation of the transient/tonal makeup of the post-split signal on separate lines—transient information in blue and tonal in green.

You can also vary the transient/tonal balance at the end of the signal chain using the separate output gain controls for each. Moreover, the Transient or Tonal signal can be soloed at the output.

Using Structural Split, alone, offers the capability to create cool effects, including reducing the transient signal to make a tonal instrument sound like it was bowed, or cutting out most of the tonal side to create a staccato sound. Once you add the effects on top, the possibilities are endless. Delays and Tremolo can be set to the host tempo to create rhythmic complexity, while the phaser includes an LFO that can be used to create a fine, boingy modulation effect.

Fission can also change the pitch of a drum sound without affecting its transients, or apply tremolo only to the tonal section of a guitar, leaving the attacks unaffected. Any source can be manipulated and tweaked in ways that were not possible before.

To give users an idea of Fission’s potential, Eventide provides a variety of presets, including a bank of Artist Presets from Richard Devine, Suzanne Ciani, Joe Chiccarelli and many others.

Overall, Fission is a unique and powerful processor for creating completely original effects. Eventide offers a 30-day fully functional demo of the plug-in, which is definitely worth the time to check out. You won’t be disappointed.

Processes tonal and transient elements separately. Effects can be applied to either side of split signal. Adjust the balance between tonal and transient signals. Artist presets. Included in the Ensemble Subscription.

Focus slider is a bit counterintuitive.


Mike Levine is a composer, producer, and multi-instrumentalist from the New York area.