pub const BAND_FLOOR: f32 = 1e-4;Expand description
Silence floor for the band scalars and the 64-band array.
The floor is the one place an absolute magnitude survives, so it is the one place gain-portability can break: a band whose running peak sits under the floor reads 0 where a louder copy of the same track reads 1. That makes the margin, not the value, the thing to get right.
Measured against signal::dynamic_groove: the three band scalars peak at
0.020-0.109 and every one of the 64 bands peaks above 0.011. At 1e-4 that
is a 110x-1000x margin, so the same material still clears the floor a decade
below -20 dB. An earlier draft used 1e-3 and was wrong for exactly this
reason — only ~6x over real mid/treb means, so a -20 dB track lost its mid
and treble entirely and read as bass-only, defeating the portability this
whole change exists to buy.
Downward, a -80 dBFS room noise floor spreads its energy across bins and lands well under 1e-4, so it is still suppressed rather than amplified.