L
OW CUT FREQUENCY FILTER
The TRP3’s Low-Frequency filter (ref.
#
5) features two 6
dB per
octave slopes at 115 Hz and 230 Hz. This Low-Frequency filter is
intended to moderate the bass boost “proximity effect” inherent
with a ribbon microphone when used up close.
Directional microphones when moved closer on-axis to a sound
source become more sensitive to low frequencies. This proximity
effect becomes more pronounced the closer the
distance. With
some Big Ribbon™ mics, such as the AEA R44C, proximity effect
begins at six feet and is extremely pronounced at a distance of
one inch.
However, sometimes such strong low frequency content
can mask high frequency intelligibility. The TRP
3
’s high-pass filter
helps
diminish this low frequency energy. The frequencies of the
TRP3's high-pass-filter were specifically chosen to tame the
proximity on a variety of microphones in a variety of
configurations, especially AEA ribbon mics.
P
OWER SUPPLY
An external switching power supply with a grounded AC plug is
used with the TRP3 so hum fields can be kept away from the high-
gain electronics. The power supply allows the TRP3 to be used in
any country without any modifications made to the unit.
The power supply is a universal switching supply
.
I
t provide
s
3
regulated o/-18.5
VDC and 52
VDC
;
these voltages are
then
regulated internally again to provide clean power for the unit.
The power supply is not designed to be used in a wet
environment.
9
