Solidyne 542 APC, Руководство пользователя

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✔
Turn the wheel to select BACK and press to exit.
✔
Turn the wheel to the last "BACK" icon to leave the
SETUP menu. Changes are saved automatically.
INPUTS: Set the current active input and the inputs gain.
OUTPUTS: Set the level for the audio outputs.
STEREO GENERATOR
Set the level for the pilot tone;
the moduation index for RDS
sub-carrier and the levels for
MPX-1 and MPX-2 (in volts
peak to peak).
FM RECEIVER
Allows to set the FM band type
and tuned frequency.
ETHERNET
Allows connection to a LAN
to access the internal WEB
screens. By default, the de-
vice comes in DHCP mode.
The home screen displays the
current IP address.
3.2.4 FM RECEIVER
The internal FM receiver allows to tune in a FM station and
analyze the main transmission aspects. There are three
screens that display transmission data: FM MONITOR, FM
MODULATION MONITOR and RDS ANALYZER.
Figure 14: FM receiver
3.3 Processing Presets
The presets store all the values and settings of the
sound processing stages, which defines the sound on
the air.
The factory presets was created to meet different needs
of broadcasters. Some presets focus on sound quality,
others ones prioritize the loudness, the bass-boost, treble
enhancement, or the intelligibility of voice. Presets from
01 to 03 are made for voices. Presets from 04 to 13 are
for general purpose and are sorted by their loudness
level, from lowest to highest. The user can copy and edit
a factory preset to create their own preset, as is detailed
later.
At next the concept behind the presets are described.
We recommend to rear carefully the following notes.
3.3.1 VOICE PRESETS
The VOICE presets are set to process the voices. When the
microphones go on-air, the 542APC can switch the preset
to process the audio with a preset designed for the voices
(see 3.11.1 Input action).
The main difference of adjustments for the voice, regard-
ing the adjustments made for the music are the times of
attack and recovery times of the AGC and compressors
and the wide-band limiter.
The wide-band AGC must recover its gain fast enough to
compensate, for example, a low-level telephone communi-
cation. This is achieved with the quick window settings, as
if the overall WB AGC times are very fast it will cause con-
stant and audible level fluctuations.
The hold threshold is set to values between 6 to 8 dB
higher than the values used for music, to avoid constant
level changes. To make this preset, we use program signal
containing a mix of announcers and promotional cuts and
ads.
The attack of the WB AGC must also be fast, but a very
fast time will cause audible level changes because of
screams or laughter that can occur in front of the micro-
phone in some types of shows. The action of the AGC
must go unnoticed.
The multiband AGC should not have a very wide correction
range. Between 2 and 3 dB is sufficient for most purposes.
The coupling between bands should not be greater than 3
dB to avoid imbalances in the spectrum, except for the
bass band that tolerates differences of 4 to 5 dB. This is
sometimes convenient as it helps to balance the presence
of bass between different voices. Remember that you can
use the MB AGC Dynamic EQ to define an equalization pro-
file.
The attack times of the compressors must be fast, mainly
in the LOW band, to contain the great impulses that take
place in the attacks of the word, when the compressors
begin to work. If the attack times are slow, excessive limi-
tation and clipping of the signal may occur at certain
speaker words, and the announcer will sound "saturated"
or "dirty" for a brief moment, when he start to speak (and
after each pause greater than the recovery time).
The recovery times are more flexibles, so they adjust ac-
cording to the type of sound that the station desire. As a
general rule, slow recovery times will produce a "soft" and
natural sound, while fast recovery times will increase the
loudness, but processing becomes more aggressive
(greater compression/limitation) and the voices sounds
harsh.
Respect to the control Drive on the limmiters, the voices
do not resist too much multiband compression. An exces-
sive processing will sound unpleasant to the ear and will
detract from the naturalness of the voices.
Audio Processing Core - SOLIDYNE 542 APC Page 17
Figure 13: Ethernet
Figure 12: FM Mode and tune
Figura 11: Stereo Coder