V O R S I S H D P 3 G U I
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HD P3 / Aug 2006
and “Threshold” is then undertaken to best control the artifact. It is nearly
always a compromise - as with any “garbage disposal” type processing -
between reducing the undesired artifact, and mitigating its effect on the
rest of the sound.
A less conventional use for the de-esser is as a dynamic EQ. Using it
to shape the frequency response at higher signal levels (leaving it alone at
lower levels) can be far less sonically obvious than digging a big hole with
conventional EQ. An example would be using the de-esser to control the
mid and mid-high frequencies of a music bed over which is to be laid a
voice-over; the bed can be kept loud and energetic - and still natural-
sounding - while not interfering with the important voice frequencies.
It should be noted that the de-esser is quite sensitive to changes in input
level; ensure that the input signal is at a reasonable level, and stays that
way, for best and consistent effect.
Emphasis and De-Emphasis
Emphasis is available at the HD P3’s input, and both pre-emphasis and
de-emphasis at the output.
Emphasis (also known as pre-emphasis, particularly in circumstances
where it is operating in conjunction with a complementary de-emphasis)
is the imposition on the frequency response of a system a fixed and known
frequency-dependent gain; the most usual implementation – and that used
here - is an emulation of the fixed 75uS (Americas) or 50uS (elsewhere)
high-frequency boost used in FM broadcast transmission. These, roughly
speaking, have a turnover frequency (at the 3dB gain point) of 2kHz and
3kHz respectively, with a 6dB-per-octave gain increase above.