I was wondering how to alter the formant of a voice within the er301. Like Sountoys Alterboy does, and any other formant tool
This would be very tricky without FFT tools. If I had to guess at a rough method for the ER-301:
- Make the analysis section of a vocoder (fixed filter bank with envelope followers)
- Track the three (or however many gives a good formant) strongest bands and their centroid
- Suppress those bands in the original signal using EQs
- Use peaking bandpass filters to emphasize different formants, centered on the centroid with adjustable spread
But this is maybe more like vocoding? Regardless, your limitation is probably on number of bands the ER-301 could reasonably analyze. The logic overhead here would be huge unless you write in the middle layer (LUA SDK). The Scorpio bespoke vocoder unit achieves 10 bands of analysis and modulation, for reference, and I don’t think that is fine-grained enough to effect the changes you want.