Review: VirSyn’s Cube Synth makes Additive Synthesis a Breeze

Over the last year or so, I’ve been focused on recording the new Church of Hed album, Electric Sepulcher, with hardware synths typically being my gear of choice compared to the venerable iPad 2. As such, I am about a year late with this profile of VirSyn’s excellent Cube Synth, which brings the esoteric world of additive synthesis within a finger swipe of any iPad owner. Users of other VirSyn iOS apps should feel right at home with the familiar interface.

Cube Synth for the iPad Features

  • Easy to Program Additive Synth Engine
  • Four Morphable Sound Sources in Each Patch
  • Up to 512 Partials per Voice
  • 8 Voices either Monophonic or Polyphonic
  • 400 Factory Presets featuring a Wide Array of Sounds
  • Harmonic/Inharmonic/Noise Spectra
  • Morphable Filters and Tempo Synced Envelopes
  • VirSyn’s Powerful Arpeggiator and Six Effects
  • Support for Audiobus 2, Inter-App Audio, Core MIDI, Virtual MIDI
  • iOS version 5.1 and greater
  • Available at the iTunes App Store for $11.99

Cube Synth’s powerful and intuitive controls make it easy to create new additive patches or modify the well-designed factory set. If additive synthesis always seemed too daunting, a few hours with this app will change your mind.

Additive Synthesis at the Touch of a Finger

In a sentence, additive synthesis creates sounds by mixing together any number of sine wave harmonics — known as partials. This allows for a wide range of sonic possibilities, but the difficulty in programming hundreds of individual sine waves for one patch made this form of synthesis less popular than its subtractive cousin. I own one hardware additive synth — the Kawai K5000W — and programming it can be tedious yet ultimately rewarding.

Cube Synth Main Screen

Cube Synth features a clear user interface with excellent use of the iPad’s touch gestures.

Cube Synth leverages the iPad’s touchscreen to make additive synthesis a relative breeze. A simple finger swipe is used to set the level for multiple partials and to control morphing filters and envelopes. Controlling the morphing with an envelope gives a patch the sense of motion typical of this form of synthesis.

Each patch uses four different sound sources; while another touch controlled 2D section located in the middle of the main interface screen lets you morph between these sound sources with your finger. Cube Synth also lets you use two dedicated envelopes for the X and Y axes. A global brightness control offers additional tweaking possibilities.

Tapping the label for one of the four sound sources (labeled from A to D) brings up another screen to manage that source’s partials as mentioned earlier. Other tabs on this pop-up screen allow easy touch programming of each partial group’s pan position, attack, decay, filter, and noise. Deep additive synthesis with a finger swipe! Boom!

Cube Synth Partials

You can edit a source’s partial set with a simple finger swipe.

A tools dialog provides the ability to copy and paste partial groups as well as load new ones from a collection covering vocal, natural, analog, and special sources.

Another User Friendly VirSyn Mobile App

You are able to program envelopes (volume and the X and Y sound source morphing mentioned above) in one of Cube Synth’s other screens accessible from the menu at the top of the interface. Once again, finger taps and swipes offer a wide range of easy control. This screen also allows you to pair modulation sources with the brightness, volume, and envelope time parameters and set the number of voices, portamento, and keyboard tracking for a patch.

Loading presets and saving your own patches is simple; accomplished by tapping on the patch name at the top of the screen. You are also able to make sound recordings and use AudioCopy, SoundCloud, or iTunes file sharing to share audio files. The latter works for sharing patches as well.

Cube Synth includes the excellent VirSyn arpeggiator/sequencer also found in their miniTera app. Creating weird time signatures is a breeze — a big plus in my book! Each patch saves its own arpeggiation, plus you can share separately between patches. Tap on the dice to create a random arpeggiation.

Cube Synth Arp Screen

Weirdo time signatures are a breeze with Cube’s Synth’s arpeggiator/sequencer.

Six effects — EQ, phaser, delay, overdrive, ensemble, chorus, and reverb — round out Cube Synth’s robust synth engine.

Cube Synth Effects

Cube Synth features six effects.

If you are an iPad owner interested in additive synthesis, Cube Synth needs to be in your app collection. If offers a user friendly path into this rewarding form of sound creation. Recommended!


  1. […] tablet music apps and more towards hardware synths and effects. It’s been a year and a half since the last iOS article. This somewhat parallels my own shift as well. My last Church of Hed album, Brandenburg Heights, […]