Crossover - Eclipse CD5000 Manuel D'utilisation

CD5000_ENG.book Page 56 Wednesday, December 7, 2005 6:22 PM
Various Settings
The "time alignment" function corrects the time taken for the sound waves to reach the listener in
order to set the optimum phase for the listening position so that the sound becomes more expansive
as though it is being listened to on a sound stage.
The basic adjustment method involves measuring the actual distances to each speaker and
calculating the differences in distance relative to the most distant speaker in order to derive the
delay time for the sound from each speaker.
When this main unit is in advance mode, a simplified time alignment function is available. You can
use this function to adjust only four parameters (position selector, vehicle type, tweeter settings and
rear speaker position settings), and so you can make basic time alignment settings without
measuring the actual distances to each speaker.

Crossover

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 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.
-3dB
Bass range
20Hz
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.
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Mid range
fc1(LPF) fc2(HPF)
Treble range
fc3(LPF) fc4(HPF)
fc*: Cutoff frequency
20kHz