About The Crossover - Alpine CDA-7998 Owner's Manual

Basic Operation

About the Crossover

Crossover:
This unit is equipped with an Active Crossover. The
crossover limits the frequencies delivered to the outputs.
Each channel is controlled independently. Thus, each
speaker pair can be driven by the frequencies for which
they have been optimally designed.
The crossover adjusts the HPF (high pass filter) or LPF
(low pass filter) of each band, and also the slope (how fast
the filter rolls off the highs or lows).
2 way mode
Cut-off frequency
(1/3 octave steps)
HPF LPF
Low range 20 Hz -
----
speaker 200 Hz
Front high
20 Hz -
range ----
200 Hz
speaker
Rear high
20 Hz -
range ----
200 Hz
speaker
Low range
(Different from actual display)
Level adjusting
(0 to - 12 dB)
NOTES
• HPF (high pass filter): Cuts the lower frequencies and allows the higher frequencies to pass.
• LPF (low pass filter): Cuts the higher frequencies and allows the lower frequencies to pass.
• Slope: The level change (in dB) for a frequency change of one octave.
• The higher the slope value, the steeper the slope becomes.
• Adjust the slope to FLAT to bypass the HP or LP filters.
• Do not use a tweeter without the HPF on or set to a low frequency, as it may cause damage to the speaker due to the low frequency
content.
• You cannot adjust the crossover frequency higher than the HPF or lower than the LPF.
8
-EN
Slope
Level
HPF LPF
FLAT, 6,
12, 18, 0 to
----
−12 dB
24 dB/oct
FLAT, 6,
0 to
----
12, 18,
−12 dB
24 dB/oct
FLAT, 6,
0 to
----
12, 18,
−12 dB
24 dB/oct
High range
Output frequency range
20 Hz
HPF cut-off
frequency
Adjustments should be made according to the reproduction
characteristics of the speakers. Depending on the
speakers, a passive network may not be necessary. If you
are unsure about this point, please consult your authorized
Alpine dealer.
3 way mode
ww frequency
(1/3 octave steps)
HPF
Low range
----
speaker
Mid range 20 Hz -
speaker 200 Hz
High range 1 kHz -
20 kHz
speaker*
∗ When setting the high range HPF filter to FLAT, do not turn up the
volume too much. This may damage the speaker.
Low range
(Different from actual display)
Slope adjusting
(Different from actual display)
LPF cut-off
frequency
Slope
LPF HPF LPF
FLAT, 6,
20 Hz -
----
12, 18,
200 Hz
24 dB/oct
FLAT, 6, FLAT, 6,
20 Hz -
12, 18, 12, 18,
20 kHz
24 dB/oct 24 dB/oct
6, 12, 18,
----
----
24 dB/oct
Mid range High range
Slope FLAT
Level
0 to
− 12 dB
0 to
−12 dB
0 to
−12 dB