Solidyne 542 APC, Руководство пользователя

Страница: 37 / 44

set between 2 and 6 dB below 100%, to leave headroom to
the other bands in the final sum.
4.7.2 WB Limiter
The sum of the bands occurs after the band limiter. Al-
though the bands were limited to 100%, the sum of the lim-
ited signals will generate new peaks in the resulting signal,
which will be above 100%.The function of the wide band
limiter is to stop the peaks produced in the sum of the
bands, limiting them to 100% of audio level. It is a "look
ahead" type with a delay time of 2 mS. The limiter "pre-
dicts" the attenuation necessary for the signal to remain at
100% and acts with zero attack time, which prevents har-
monic distortion. The threshold is fixed at 100% of the au-
dio modulation. The input gain adjustment (DRIVE) allows
amplifying the band mix, increasing the action of the wide
band limiter.
“Shape”
The wideband limiter increases the loudness for limiting
levels of up to 6dB. Above 6dB, no significant increase in
loudness is achieved, and instead unwanted effects in
the audio are generated, due to the effect of intermodula-
tion: the sound is heard "overprocessed", "without depth".
In order to work with higher wideband limiting levels,
minimizing undesired effects, 542APC implements ad-
vanced WBL control that modifies the limiter's behavior
by introducing soft clipping for high energy levels.
The user can adjust the degree of action of the advanced
control over the limiter, but the advanced control only
comes into play when the peak density is high, which al-
lows its action to be masked to the ear.
4.7.3 MPX cliper
At the end of the processing chain, the SUM (L+R) and
SUBTRACT (L-R) signals are trimmed separately with a
soft clipper. The threshold is located at 100% modulation.
The “DRIVE” control is critical, as it applies gain to L+R and
L-R before the clipper.
If DRIVE = 0 the clipping has practically no effect; but 1dB
of gain implies 1dB of clipping in the signal. Values of 0.5
to 1dB are tolerable for most cases. Values greater than
1dB can be used but produce a harsher sound, which
some refer to as “FM sound” (FM style). Use this tech-
nique only if it is necessary to achieve high loudness levels
in the air.
4.9 Manage the presets
The unit has 16 processing presets, and 16 free memo-
ries for the user to create their own settings. Factory pre-
sets are only-read and can not be edited.
Figure 39: Sound Presets
CURRENT PRESET is the active preset, the processing
applied to the sound on the air.
REFERENCE PRESET is to load a second preset and put
it on the air, in order to compare its sound against the
current setting. By pressing “COPY REF TO CURRENT”,
the reference preset can override the current preset
when it is a user memory.
ON AIR:
Switch the on-air preset between CURRENT and
REFERENCE.
4.8.1 Create a preset
Presets are created in the SETUP screen. To create a
new preset, the user can directly edit a user preset or can
copy a factory preset and then modify it (recommended).
Only the preset loaded as CURRENT PRESET
can be edited when it is on air. When the
REFERENCE option is on the air, editing is
disabled.
The preset loaded as a reference (REFERENCE) is used
to compare two presets, listening to the sound on the air
and visualizing the values of the processes.
To copy a factory preset proceed:
1. Load the preset that you can copy in the field REF-
ERENCE PRESET. When a read-only preset is
loaded in this field, the SAVE button changes to
EDIT - Copy to UserMem
2. Press EDIT - Copy to UserMem . A screen for
choosing the copy destination position will ap-
pear.
3. This screen also allows you to edit the name of
the preset.
4. Press the APPLY button. The factory preset will
be copied to the chosen user position. The exist-
ing user preset is overwritten.
4.9.2 Preset Manager
The Preset Manager is accessed from the main menu of
the WEB Control panel. It allows you to perform the fol-
lowing actions:
•
Export a preset to a file on the hard disk.
•
Import a preset from disk / pendrive
•
Copy factory presets to user memories.
Audio Processing Core - SOLIDYNE 542 APC Page 37