A preset presents the user with an augmentation scheme. Some presets allow creating sharp and distinctive variations in tone, thus easily turning objects into percussion instruments. Other presets implement an onset detection algorithm that detects hits to drive physical models of instruments, thus allowing for control of pitched instruments.
Rather than letting the users start an effects chain from scratch at the outset, the app confront them with a set of presets offering radical rather than subtle augmentations, designed to immediately immerse him in a distinct auditory experience from the outset. By easily and forcefully demonstrating what different sounds the app is capable of, we hope to encourage engagement with it.
With regards to best practices for effects such as chorus and reverb, Andy Farnell, author of Sound Design, insists “Always use them sparingly”. We followed instead the approach suggested by instrument-makers such as Hopkin: “Try to let the instrument and its sound suggest their own music”, and by Perkis:
“I don’t really think that much about this process of sound design can be automated or abstracted: it’s a matter of making very particular and arbitrary decisions. There’s no substitute for time and taste, in trying, listening, rejecting and accepting, following intuitions about what sounds good”.
The sound is mixed with a very slightly delayed copy of itself, pitch-modulated at 2856Hz, then sent through a one-pole filter with a very high gain. Contrasting sounds can be obtained by changing the modulation frequency. Percussionists found that the preset produced a sound with “rich bass”, despite the supposedly noisy emphasis of the lower frequencies by the iPhone’s microphone.
An effect similar to AriOne, though the output is mixed with a perceptibly delayed modulated version of it, creating a response to the hits. The frequency and harshness of the echoed sound can be controlled.
Soft hits drive a physical model of a marimba, slightly reverbed and combined with a delayed copy of the sound at a user-adjustable frequency.