How far (bins) around bin/2 and bin/3 pshr scans for a sub-harmonic line. A true
half/third partial lands mid-bin in the worst case (bin/2 and bin/3 are rarely integers)
and spectral leakage smears it one bin further; ±2 covers both. Measured on the #116
live-music corpus: every false positive's sub-line sat inside this window. Deliberately
NOT wider — at low bins the window is already a large fraction of an octave, and widening
it would start reading unrelated program lines as "sub-harmonics" of real feedback.
How far (bins) around bin/2 and bin/3 pshr scans for a sub-harmonic line. A true half/third partial lands mid-bin in the worst case (bin/2 and bin/3 are rarely integers) and spectral leakage smears it one bin further; ±2 covers both. Measured on the #116 live-music corpus: every false positive's sub-line sat inside this window. Deliberately NOT wider — at low bins the window is already a large fraction of an octave, and widening it would start reading unrelated program lines as "sub-harmonics" of real feedback.