PSHR — peak-to-subharmonic power ratio, in dB: the candidate bin's level minus the
strongest spectral line near bin/2 or bin/3 (±SUBHARMONIC_RADIUS_BINS bins).
PHPR's mirror, looking DOWN the spectrum (deferred from issue #106, landed as #116): a
candidate with a strong line at f/2 or f/3 is a musical OVERTONE riding on its own
fundamental / lower partial — feedback has no sub-harmonics, a loop rings at one
frequency and leaves everything below it to the program. Sub-window bins overlapping the
candidate's own skirt (within 2 bins of bin) are skipped so a low-bin candidate never
measures itself; no measurable sub-window at all reads +Infinity (nothing below to
accuse, so the ratio can never wrongly reject).
PSHR — peak-to-subharmonic power ratio, in dB: the candidate bin's level minus the strongest spectral line near bin/2 or bin/3 (±SUBHARMONIC_RADIUS_BINS bins). PHPR's mirror, looking DOWN the spectrum (deferred from issue #106, landed as #116): a candidate with a strong line at f/2 or f/3 is a musical OVERTONE riding on its own fundamental / lower partial — feedback has no sub-harmonics, a loop rings at one frequency and leaves everything below it to the program. Sub-window bins overlapping the candidate's own skirt (within 2 bins of
bin) are skipped so a low-bin candidate never measures itself; no measurable sub-window at all reads +Infinity (nothing below to accuse, so the ratio can never wrongly reject).