SL CastShift

Give your audio a different voice. SL CastShift is an AUv3 audio effect for iPhone and iPad that combines six transmission and media characters in one sound-design workflow: Radio, Phone, TV, Walkie, Megaphone and Codec. Start with 18 factory presets, three for each mode. Shape the result with Drive and Mix, high-pass and low-pass filters, Bass, Mid and Treble, then add Age, Distort, Bitcrush, Noise, Wow and ambience. Each preset recalls the complete sound. The AI control blends local adaptive processing using embedded neural models. Processing runs on your device, with no cloud inference or model download. Use CastShift as an AUv3 effect on an audio track in a compatible host. Feed it vocals, instruments, loops or sound effects and compare the six modes. This is an audio effect, not a MIDI instrument: it needs an audio source. The interface adapts to iPhone portrait and landscape, iPad and compact host windows. The standalone app does not automatically enable microphone-to-speaker monitoring. For processing audio from another music app, load the AUv3 extension in a compatible host.