6
Ultrasonic Filter
Applications: An ultrasonic filter is useful for minimizing RF interference, oscillations,
leakage or aliasing from digital devices, or other signals that are too high in pitch to hear but
may wreak havoc in an amplifier system.
Typical ultrasonic filters are set at 16 kHz or 20 kHz.
Program settings:
1 Set J201 to enable the low-pass filter by placing jumper across pins 2 and 3.
2 No jumper on J203 unless you need CD horn equalization.
3 Insert proper resistor network in RN202 socket.
CD Horn Equalization Filter
Applications: A constant directivity horn requires a 6 dB per octave boost at high frequen-
cies to provide a flat frequency response. On the MPC-X100 you must use the CD horn
equalization in conjunction with the 100 Hz high-pass filter.
Program settings:
1 Set J202 to enable the 100 Hz high-pass filter by placing jumper across pins 2 and 3.
2 Set J203 to select the EQ curve you desire: across pins 1 and 2 to +6 dB at 20 kHz, or
across pins 2 and 3 for +10 dB at 20 kHz.
MPC-X100
Subwoofer
Full-range
speaker system
F=
100 Hz
C
2-Way Active Crossover
This configuration routes the frequencies below 100 Hz to amplifier Channel 1, which will
driver the subwoofer(s), and the frequencies above to Channel 2, which will drive the full-
range (typically, woofer + high frequency as passive 2-way, or woofer + midrange + high
frequency as passive 3-way) speaker(s). Using the MPC-X100 as a crossover requires that you
drive both amplifier inputs with the same full-band signal.
Program settings:
1 On the input module, set the amplifer mode to parallel. Alternately, you could use a Y-
cable to provide the same signal to both channel inputs.
Channel 1:
2 Subsonic (infrasonic) filterIf you need subsonic (infrasonic) filtering, set J102 to enable the
high-pass filter by placing jumper across pins 2 and 3, and insert a resistor network into RN104
corresponding to the roll-off frequency you desire. If you do not want subsonic (infra-
sonic) filtering, set J102 to disable the high-pass filter by placing jumper across pins 1 and 2.