Specifications

Processing Parameters
17
PROCESSING PARAmETERS
User Level: This parameter allows you to select between beginner and advanced modes. Beginner mode
restricts access to certain menus and controls.
The 'INPUT' menu contains all of the options and parameters relating to the control and conditioning of
the audio inputs.
Source This parameter allows you to select the between the analog and digital inputs as the source for the
processing.
Input Mode: This parameter allows you to select different mono options as well as the default Stereo option.
There is also the ability to swap the left/right channels.
Analogue Input A/D Clip Level: Allows you to set the analogue input level with reference to the
DSPXtreme's A/D converter clip celeing. This would normally be set to +24dBu if driving the DSPXtreme
from professional audio equipment. This would translate to the wide-band AGC being driven to 12dB gain
reduction by a 0VU (+4dBu) audio signal. If the input level is low, you may decrease this parameter to bring
the level up and reduce signal-to-noise ratio. Make sure that the input audio meters NEVER show clipping
under any conditions.
Right Trim: This parameter allows you to adjust the right channels gain in small increments to BALANCE
out any small gain discrepancies between the left and right channels. The range is +/- 3dB.
Input Fail Switch: This parameter allows you to turn on the silence detection system and specify a silence
time. When enabled this parameter will switch the input source from the primary to the secondary source
when a predetermined length of silence occurs.
High pass filter: This parameter allows you to select from a variety of high pass filters. You can select from
20Hz, 30Hz, 40Hz, 50Hz and 60Hz. You also have the ability to bypass the high pass filter with the 'OFF'
option. The high pass filter can be used to reduce rumble on vinyl or can be effective in removing low fre-
quency energy that could otherwise cause carrier shift (AFC LOOP) problems in older FM transmitters. We
suggest you leave the high pass filter off unless you have a reason to turn it on.
Phase Rotator: This parameter if enabled will help to reduce vocal distortion in aggressive presets by reduc-
ing asymmetry in the voice which would otherwise put more workload on the clipping stages. We recommend
enabling this option if you want competitive loudness; otherwise leave it off as the phase rotation process
does colour the sound slightly, although this coloration is often used for artistic effect.
Pre-emphasis: This parameter allows you to activate pre-emphasis when the DSPXtreme is being used to
process for FM broadcast. The available options are 50 µs, 75 µs and OFF.
The 'PROCESS' menu allows access to all of the processing blocks that make up the DSPXtreme. There
are only sub-menus inside the 'PROCESS' menu. The submenus are laid out in the same configuration
as the signal path through the DSPXtreme.
The multi-band AGC in the DSPXtreme like any automatic gain control device is designed to correct input
level fluctuations and provide a consistent level to the other DSPXtreme processing blocks that follow it. The
AGC in the DSPXtreme is designed to operate in an undetectable, unobtrusive manner similar to a trained
operator controlling a mixing desk.
'AGC BYPASS' If you will be using an outboard AGC or if a processor is placed on the other side of an
studio-to-transmitter link with the AGC unit being used in front of the link, AGC in DSPXtreme can be
bypass in order to avoid "figthing" with the preceeding AGC.
'WINDOW GATING' A separate gating control from the silence gate, the window gate slows down the
attack and decay rates when the audio waveforms level has not moved outside of a pre-defined window,
set by the window gating control. The window can be set between 1 and 6dB or the gate function can be
disabled by setting the control to OFF. The window gating prevents unnecessary gain control when the
audio waveform is already well defined or having a low peak to average ratio. The window gating also
allows faster rates to be used without the audible effects normally associated with the faster rates.