Datasat RS20i, Инструкция по установке и эксплуатации

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RS20i Installation and Operating Guide Page 87
RS20i Installation & Operating Guide Document # 9301H52900 Ver. 1.00
The output preset channel name refers to the input channel only. The channel name for the output
channel (if used) will be a combination of the corresponding input and the crossover letter (for example,
Left-H).
Setup (System) > Inputs > Output Preset > Channel Names
Figure 67. Assign Channel Names Screen (with Presets)
To change or enter a new channel name select the white field next to the desired channel. A keyboard
will appear allowing you to enter text. Type in the channel name then select
OK . The channel name
will now appear in the field and in the Home Screen (in yellow text just below the channel numbers).
When a VU button is highlighted green, that channel will display VU bars on the Home screen.
To turn off the VU meter in the Home Screen simply touch the green VU symbol next to the channel
name. It will change to grey color and will no longer be displayed on the Home Screen.
4.3.8.4 Routing Crossovers
Crossover use can be attributed to the inability of most drivers to reproduce the entire audio spectrum
smoothly and efficiently. Because of this, most speaker systems are comprised of several drivers, each
of which is dedicated to the reproduction of a specific range of frequencies.
These frequencies are routed to the appropriate driver by a crossover network. This device divides the
audio spectrum into two or more frequency bands. By doing this, each driver will receive only the
frequencies that it can reproduce properly. The crossover network also prevents potentially damaging
low-frequency energy from reaching the midrange or tweeter drivers.
This frequency division process is accomplished by using high-pass and low-pass filters. A high-pass
filter passes frequencies above a pre-determined frequency and attenuates those below. This pre-
determined frequency is called the crossover point. Conversely, a low-pass filter passes frequencies
below the crossover point and attenuates those above. By cascading high-pass and low-pass filters, a
band-pass filter can be realized. Filters of this type attenuate all frequencies outside of the pass-band
created by the high and low-pass filters.
The rate at which the attenuating process takes place is dependent upon the slope of the crossover. A
typical slope for cinema sound systems is 24dB/octave. Higher numbers indicate a much steeper cutoff
rate while the lower numbers indicate a more gradual roll-off.