pub const WAVE_FLOOR: f32 = 1e-3;Expand description
Silence floor for the waveform trace, in signal amplitude — a different
quantity from BAND_FLOOR, which is a band mean, and deliberately an order
of magnitude above it.
A band mean spreads a signal’s energy across bins, so a -80 dBFS room lands
well under 1e-4 there. A time-domain peak does no such spreading: -80 dBFS
is an amplitude of 1e-4, so BAND_FLOOR copied here would sit exactly
at room noise and amplify it to a full-scale trace — the one failure a floor
exists to prevent.
Measured against signal::dynamic_groove at 48 kHz, per 120 bpm beat: the
trace peaks at 0.900 through the loud phrase and at 0.206 in the two
resting beats, whose 0.04 phrase scale is the quietest material the
stimulus contains. So 1e-3 (-60 dBFS) leaves the quietest real material
206x clear of the floor, and the same material a decade down the fader
still 21x clear — levelled rather than zeroed. Downward it suppresses a
-80 dBFS room by a decade and 16-bit dither (LSB 3e-5) by two.
the_floor_clears_real_material_by_two_orders_of_magnitude is the margin,
asserted as a ratio rather than as this paragraph’s readings.