spectra is blepfx's spectral morphing plugin. It splits a main input and a sidechain into an envelope and a whitened harmonic layer, then morphs those layers on an XY pad. Four algorithms cover the transfer: Linear and Hilbert FFT modes, an LPC mode with a vowel character, and a zero-latency IIR vocoder bank. Formant shift runs from −24 to +24 semitones, with Smooth, Smear, Freeze, and Tilt on the same envelope.
The official price starts at $25, VAT included. A free demo is on the page and has limitations. Formats are VST3, AU, and CLAP on macOS, Windows, and Linux. There is no AAX build.
Choose spectra to paint one spectrum onto another. Choose zplane TIMBRE for dual-band formant shift without a morph, or Little AlterBoy for mono pitch, formant, and hard-tune. For the full breakdown, see the spectra first look.