Eclipse - Fujitsu Ten CD8443 Car Satellite Radio System User Manual


 
70
How to operate the Sound Adjustment Mode
For example, when adjusting the HPF, frequencies that are
lower than the specified frequency are progressively
dampened, rather than simply not being played back at all.
The "slope" adjustment function is the function that is used to
adjust these dampening characteristics.
The slope characteristics of a filter are such that with larger
slope values (for example 12 dB/oct), the slope becomes
steeper, and so the amount of sound mixing in with
neighboring bands becomes less so that only the target band
is played back. However, it also causes the merging of sound
between speakers to become poorer and can result in greater
distortion.
20Hz
-3dB
Bass range
20kHz
fc1(LPF) fc2(HPF) fc3(LPF)
fc*: Cutoff frequency
fc4(HPF)
The frequency band that is stored by audio media such as CDs
is a fairly wide range from 20 Hz to 20 kHz, and it is difficult for
a single speaker to be able to play back all frequencies in such
a wide range.
Because of this, several speakers can be used, with different
frequency bands (such as treble, medium and bass) allotted to
each speaker so that wide frequency ranges can be played
back.
The "Crossover" function is used to allot the frequency ranges
that are to be played back by each speaker in accordance with
the installed speaker units and the layout of the speakers, in
order to obtain the maximum level of performance from the
speakers and to provide the most stable frequency
characteristics.
The crossover function includes a high-pass filter (HPF) for
playing back treble sounds, and a low-pass filter (LPF) for
playing back bass sounds. In addition, the HPF and LPF are
used in combination in order to play back sounds in the
medium range.
CROSSOVER
Medium range
Treble range