DP324 Unit Manual
Designed & written by Waring Hayes 11/2000
Quick Reference
Editing Parameters: press ‘A’/’COMP’/’LIMIT’
etc. for access to relevant section. 1st press
accesses that module’s threshold and most
important parameters. To scroll through a
module’s parameters, use the BACK and NEXT
keys. 2nd press accesses last viewed parameter. 3rd
press will display module overview information.
Accessing Menus: press the MENU key. Use the
BACK and NEXT keys to select the sub-menu
required, and enter using the ENTER key. This
applies to all levels of menu. ENTER always
confirms selections. Double pressing MENU will
jump to the last viewed selection.
The Menus and their Contents:
Memory Sub-menu: Used for storing and recalling
settings either module by module, or for entire
channels. Also used for storing and recalling
complete memory sets using a PC card, and
preview of memories and presets.
Configuration Sub-menu: Used for setting
expander or gate action, stereo linking, control
ganging, editing level, and naming channels.
Security Sub-menu: Used for locking the front
panel of the unit with a four digit code.
System Sub-menu: Used to view the unit’s status,
and select various global options such as
parametric EQ ‘Q’ or bandwidth units, LCD
brightness, LCD contrast, and meter mode
(meters on or off in bypass). Unit software
updates from a PC card and unit cloning are
accessible here.
Ext. Interface Sub-menu: Used to configure the
remote control interface(s).
AES/EBU Sub-menu: Used to configure the digital
audio interface(s), if fitted.
Notes:
The sidechain listen function only operates when a
module is being edited.
The input meters show level, in dB, from clipping
the input converter, prior to the input gain control.
The STEREO LED only illuminates when all
modules are stereo ganged.
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DP324 Operators Manual
Contents
QUICK REFERENCE
2
Contents
3
Important Safety Information
6
Thanks
7
Unpacking SIDD
7
Introduction
8
Features ................................................................................................................................................................. 8
Front Panel Familiarisation
10
Rear Panel Connections
11
Operating SIDD
12
Audio Function Screens – Input EQ etc.
13
Audio Function Screens – Dynamic EQ Module
16
Note about operation with WindowsTM software. ............................................................................................ 12
Preliminary Set-up ............................................................................................................................................... 12
Main Delay Screen ............................................................................................................................................... 13
ADT Screen ......................................................................................................................................................... 13
Harmonics Screen ............................................................................................................................................... 14
High Pass Filter Screen ........................................................................................................................................ 14
Low Pass Filter Screen......................................................................................................................................... 14
Parametric Filter Screens..................................................................................................................................... 15
Input Channel Summary Screen........................................................................................................................... 15
Attack/Release Screen ......................................................................................................................................... 16
Dynamic Filter Section......................................................................................................................................... 17
Operating Mode .................................................................................................................................................. 17
Dynamic Equaliser Summary Screen ................................................................................................................... 18
What does the metering show? ........................................................................................................................... 18
Audio Function Screens – Noise Gate / Expander Module
19
Attack/Release Screen ......................................................................................................................................... 20
Sidechain High Pass Filter .................................................................................................................................... 20
Sidechain Low Pass Filter..................................................................................................................................... 20
Sidechain Parametric Filters................................................................................................................................. 21
Gate/Expander Summary Screen......................................................................................................................... 22
What does the metering show? ........................................................................................................................... 22
Audio Function Screens – Compressor Module
23
Threshold/Ratio/Make-up Gain Screen................................................................................................................ 23
Attack/Release/Knee Screen ................................................................................................................................ 23
Sidechain Parametric Filters................................................................................................................................. 24
Compressor Summary Screen............................................................................................................................. 25
What does the metering show? ........................................................................................................................... 25
DP324 Operators Manual
Page 3
Audio Function Screens – Limiter Module
26
Threshold/Overshoot Screen .............................................................................................................................. 26
Attack/Release Screen ......................................................................................................................................... 26
Sidechain Parametric Filters................................................................................................................................. 27
Limiter Summary Screen ..................................................................................................................................... 28
What does the metering show? ........................................................................................................................... 28
Context Aware Sidechain Monitoring
29
The Menu System
31
Memory Sub-menu
32
Memory Configurations and Presets – How Are They Organised? ..................................................................... 32
Recalling a Preset or a User Memory .................................................................................................................. 33
Previewing a Preset or a User Memory............................................................................................................... 34
Let SIDD select the memory type for you!.......................................................................................................... 35
Storing a User Memory ....................................................................................................................................... 36
Erasing a User Memory ....................................................................................................................................... 37
PCMCIA Cards – What can they be used for?..................................................................................................... 38
Saving Memories to a PC Card............................................................................................................................ 39
Loading Memories from a PC Card ..................................................................................................................... 40
User Memory Resources ..................................................................................................................................... 40
Configuration Sub-menu
41
Global or Individual Settings ................................................................................................................................ 41
Expander / Gate Option ...................................................................................................................................... 42
What is the Difference Between Stereo Ganging and Function Linking? ............................................................. 43
Stereo Ganging .................................................................................................................................................... 44
Function Linking................................................................................................................................................... 45
SIDD’s Configurations
46
Security Sub-menu
52
Configuration Menu cntd. : Channel Routing....................................................................................................... 48
Channel Names ................................................................................................................................................... 49
Function Modes ................................................................................................................................................... 50
Locking the Unit .................................................................................................................................................. 52
Unlocking the Unit............................................................................................................................................... 52
Forgotten the Code?............................................................................................................................................ 53
System Sub-menu
55
System Status Information ................................................................................................................................... 55
LCD Contrast ...................................................................................................................................................... 55
LED Brightness .................................................................................................................................................... 56
Program Update .................................................................................................................................................. 56
Preset Update...................................................................................................................................................... 57
Wake-up Time..................................................................................................................................................... 57
Filter Q or Bandwidth (BW) ................................................................................................................................ 57
Delay in Time/Distance ....................................................................................................................................... 58
Meter Operational Mode..................................................................................................................................... 58
Unit Cloning......................................................................................................................................................... 58
Ext. Interface Sub-Menu
60
Interface Operation ............................................................................................................................................. 60
Single Unit System ............................................................................................................................................... 60
Multiple Unit System ........................................................................................................................................... 61
AES/EBU Sub-Menu
62
Digital Connections ............................................................................................................................................. 62
Routing Options................................................................................................................................................... 62
AES Diagnostics ................................................................................................................................................... 62
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DP324 Operators Manual
Typical Interface Set-ups
63
RS232 Connection (Single Unit) .......................................................................................................................... 63
RS232 Connection (Multiple Units) ..................................................................................................................... 63
RS485 Connection ............................................................................................................................................... 64
Midi Connection .................................................................................................................................................. 64
Look Ahead Delay – Pre-emptive Action
65
Operating Notes
68
Operating Level ................................................................................................................................................... 68
Grounding............................................................................................................................................................ 68
Time Alignment ................................................................................................................................................... 69
Specifications
70
Warranty
71
Options and Accessories
71
Appendices
72
Appendix 1: Limiter threshold in dB to Vrms lookup table. ............................................................................... 72
Appendix 2: Equalisation Curves ........................................................................................................................ 73
Appendix 3: Frequently Asked Questions ........................................................................................................... 75
DP324 Operators Manual
Page 5
An example of this equipment has been tested and found to comply with
the following European and international Standards for Electromagnetic
Compatibility and Electrical Safety:
Radiated Emissions (EU):
RF Immunity (EU):
Electrical Safety (EU):
EN55013-1 (1996)
EN55103-2 (1996) RF Immunity, ESD, Burst Transient,
Surge, Dips &Dwells
EN60065 (1993)
Important Safety Information
Do not remove Covers.
No user serviceable parts inside, refer servicing to qualified service personnel.
This equipment must be earthed.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
DO NOT EXPOSE TO RAIN OR MOISTURE
ATTENTION
RISQUE DE CHOC ELECTRIQUE
NE PAS ENLEVER
NE PAS EXPOSER A LA PLUIE NI A L’HUMITE
It should not be necessary to remove any protective earth or signal cable shield connections.
Do not defeat the purpose of the polarized or grounding-type plug. A polarized plug has two
blades with one wider than the other. A grounding type plug has two blades and a third
grounding prong. The wider blade and the third prong are provided for your safety. When the
provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete
outlet.
Only use this equipment with an appropriate mains cord.
In the USA the cord should comply with the requirements contained in the Standard for Cord
Sets and Power Supply Cords, UL 817, be marked VW-1, and have an ampacity rating not less
than the marked rating of the apparatus.
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DP324 Operators Manual
Thanks
Thank you for choosing SIDD for your application. Please spend a little time reading
through this manual, so that you obtain the best possible performance from the unit.
All XTA products are carefully designed and engineered for cutting-edge
performance and world class reliability. If you would like further information about
this or any other XTA product, please contact us.
We look forward to hearing from you in the near future.
Unpacking SIDD
After unpacking the unit, please check it carefully for any damage. If any is found,
immediately notify the carrier concerned - you, the consignee, must instigate any
claim. Please retain all packaging in case of future re-shipment.
DP324 Operators Manual
Page 7
Introduction
SIDD is a powerful DSP based audio processor, ideally suited for live sound
applications, where it combines the functions of a multitude of conventional products
in a compact 1U unit. To achieve this, it has two inputs and two main outputs,
together with two auxiliary outputs.
Each channel has a six band parametric equaliser and delay line, a separate variable
gain ‘A.D.T.’ delay and a harmonics generator, as well as four fully featured dynamics
modules, designed to cope with all possible processing applications.
Remote control is catered for in the form of MIDI, RS232 and RS485 ports, and
multiple user memories are provided for the storage and recall of settings. Security
lock-out is available for all controls.
SIDD is also available with optional AES/EBU digital inputs and outputs.
It has been designed for quick, intuitive adjustment through the use of multiple
controls to provide an easy-to-use interface. Alternatively, it may be controlled
externally by
XTA’s proprietary WindowsTM software, along
with up to
thirty one other units.
TM
Features
♦ Superb audio quality – carefully optimised double precision signal processing
coupled with a 40-bit internal data path ensures a dynamic range in excess of
110dB. The high sampling rate means minimal filtering providing exceptional
sonic purity.
♦ A highly accurate 6 band parametric equaliser on each input, providing +15 to
–30dB of gain at centre frequencies between 20Hz and 20kHz, with a wide
range of ‘Q’s available between 0.4 to 128. All parameters feature fine
resolution with 1/36 octave frequency steps, 0.1dB gain increments, and 100
‘Q’ settings. Any parametric section can also be set to operate as a high or
low shelving filter.
♦ A fully featured compressor with two bands of sidechain equalisation, and
featuring variable knee and ‘look-ahead’ delay for absolute control.
♦ A noise gate / expander, again with dedicated sidechain processing – high and
low pass filters plus two parametrics. The ‘look ahead’ design allows the gate
to open before the signal arrives, completely eliminating clicks.
♦ A dynamic equaliser – compress or expand only the frequency band you
choose, with unprecedented control and precision.
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DP324 Operators Manual
♦ A delay line with separate ‘A.D.T’ module that may be routed to the auxiliary
outputs. This allows for ‘staging’ of performers ‘front/back’ and ‘left/right’ of
the soundstage.
♦ A ‘brickwall’ limiter with sidechain EQ and ‘look ahead’ ability for preemptive adaptation to signal peaks, and so complete prevention of overshoot.
♦ A harmonics generator to introduce controlled levels of second and third
harmonic distortion, for simulation of ‘valve’ sound characteristics.
♦ Three velocity-sensitive encoders provide a familiar and intuitive control
format with all filter information displayed simultaneously on a 2 x 24
character backlit LCD screen.
♦ The comprehensive standard specification also includes 256 memories, PC
Card storage and remote control via MIDI, RS232 or RS485 ports, with
security lock-out.
♦ AES/EBU digital input and output interfaces are available as an option.
♦ Input and output balancing transformers are also available as an option.
DP324 Operators Manual
Page 9
Front Panel Familiarisation
LCD Screen : shows
menu options, channel
information, and various
parameters as they are
adjusted.
Next Key : moves forwards through the list of available parameters.
Back Key : moves back through the list of available parameters.
Menu Key : activates the main menu. Pressing a second time selects
the last menu edited. Selection of different menus is accomplished using
the Back and Next keys, or by turning the encoder 3.
Enter Key : enters the chosen menu and confirms choices.
Bypass Key : bypasses the currently selected processing module.
Quit Key : exits the menu.
Encoders : three velocity sensitive controls allow the relative
parameter displayed on the LCD screen to be adjusted.
PC Card : PCMCIA card slot allows back-up of memory sets,
unit cloning data and facilitates the download of software
updates and preset files.
Input Meter and EQ Edit Key: displays available headroom below clipping,
before the input gain control. The red LED illuminates 3dB below the
clipping point of the input circuitry. EQ, delays, harmonics and gains are all
accessible with this key.
Module Edit Keys: pressing the required module key will display
the main parameters available for editing. The associated EDIT
LED will illuminate. Use the ‘BYPASS’ key to switch the module
in or out of the signal path whilst edit is active. ‘In’ is shown by
the ‘ACTIVE’ LED being illuminated.
Output Meter: display headroom below clipping for all modules
combined output.
Listen Key: routes the appropriate sidechain signal to the
outputs, dependant on the module being edited.
Stereo LED: Illuminates when all modules are linked for stereo operation.
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DP324 Operators Manual
Rear Panel Connections
Power Switch: turns the units mains supply off and
on.
Mains Fuse: located in a finger-proof holder
adjacent to the mains inlet. A spare fuse is also
located in this holder.
Mains Inlet: connected via a standard IEC socket.
External: RS232 standard via a 9 pin D-type connector,
for connection to a PC. Data is converted to RS485
standard and relayed to slave units via the RS485 sockets.
Midi In: 5 pin DIN socket. See page 60 for more
information.
RS485 In-Out: XLR sockets. Used for transmission of
remote control data over long distance or multiple unit
applications. See page 60 for more information.
Audio In-Out: 3 pin XLR sockets are provided for each
channel. All are fully balanced, pin 2 hot, 3 cold, 1
screen.
Always replace the fuse with the correct type and rating as shown on
the rear panel legend.
DP324 Operators Manual
Page 11
Operating SIDD
Note about operation with
TM
WindowsTM software.
The following operating information covers control of SIDD via the front panel
controls only. Please consult the manual supplied with this software for information
regarding computer control.
Preliminary Set-up
The procedure below should be followed when first installing SIDD.
Start with a clear audio path! By default, all processing modules are switched out of
circuit, and all EQ is set to 0dB. The result of this is that the signal going into the unit
should be at exactly the same level as that coming out. It’s best to introduce modules
one at a time, if a lot of processing is being applied. This way, the effects of each
module on the final signal can be carefully gauged.
Use the edit keys on each module, together with the BACK and NEXT keys to select
the parameters required for editing. Note that the default function mode is ‘Expert’
– that is, all parameters will be displayed. See page 50 for further details of how to
adjust the function mode.
Note that when in a menu, ENTER is always used to confirm selections. The current
selection is marked with an asterisk ‘*’.
Note that if no action is taken in menu mode, the unit will return to normal ‘default’
mode. Repeat the above directions to return to menu mode.
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DP324 Operators Manual
Audio Function Screens – Input EQ etc.
Pressing the key below the input meter once will
display the first of eight possible screens associated
with editing input EQ, gain and delay parameters, and
the harmonics generator. The first press will always
display the input/output gain adjustment. A second
press will display the last selected parameter screen. A third press will show an
overall channel summary, which will be explained below.
Gain Screen
Input gain is adjustable in
0.1dB increments over a
+15dB range. It is post
converter, and so does
not affect the reading
displayed on the input meter. The output gain has the same range and increment
size, but will affect the reading on the output meter, dependant on the ‘Output
Mode’ setting.
For further details on this topic, see the section entitled “Channel
Routing” on page 48.
Main Delay Screen
The main delay is
adjustable in 21uS steps
up to a maximum of
300mS.
ADT Screen
The ADT delay is
adjustable in 21uS steps
up to a maximum of
100mS. A separate gain
control is provided for
this delay tap, offering adjustment from ‘Off’, through –60dB up to 0dB in 0.5dB
steps. When the ‘Output Mode’ is set to ‘ADT’, the ‘BYPASS’ key becomes active,
allowing the contribution of the secondary delay to be removed from the signal path
(effectively setting the gain to ‘Off’ temporarily). Gain range is increased to
-60 through +15dB maximum in ‘SPLIT’ mode.
DP324 Operators Manual
Page 13
Harmonics Screen
The harmonics generator
allows both the second
and third harmonic
distortion content of the
signal to be precisely
controlled. The addition of second harmonic distortion can be used to simulate the
affect of passing the signal through a ‘valve stage’, increasing perceived warmth. Both
second and third harmonic content are variable from ‘Off’ through –60dB to 0dB in
0.5dB steps. Additionally, the ‘BYPASS’ key may be used to temporarily switch the
harmonics off.
High Pass Filter Screen
The high pass filter may
be varied over a
frequency range from
below10Hz up to 16kHz,
in 1/36th Octave steps.
Using encoder 2, the response may be switched between 12dB/Octave Bessel and
12dB/Octave Butterworth. Note that whilst the ‘BYPASS’ key may be used to switch
the high pass filter out of circuit, the BYPASS text in the bottom left corner of the
screen does not appear. Instead, ‘Flat’ appears in place of ‘HighPass’ on the top
right of the screen.
Low Pass Filter Screen
The low pass filter may
be varied over a
frequency range from
35Hz up to 22kHz, in
1/36th Octave steps.
Using encoder 2, the response may be switched between 12dB/Octave Bessel and
12dB/Octave Butterworth. Note that whilst the ‘BYPASS’ key may be used to switch
the high pass filter out of circuit, the BYPASS text in the bottom left corner of the
screen does not appear. Instead, ‘Flat’ appears in place of ‘LowPass’ on the top
right of the screen.
Note that, to avoid loosing all signal through a channel, SIDD will not
allow the high pass filter to be set to a frequency above that of the low
pass filter, and vice versa. For example, this means that it the high pass
was set to 250Hz, the low pass would not extend down to 35Hz, but would stop at
250Hz. This action is irrespective of the bypass settings of the high and low pass.
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DP324 Operators Manual
Parametric Filter Screens
Each parametric section
can be positioned at a
frequency from 20Hz to
20kHz and features a
wide range of 'Q’s to
produce response curves ranging from broad to notch. The gain control ranges from
+15dB to -30dB in 0.1dB steps. Frequency steps are 1/36th Octave resolution for
precise control. Since all filtering is achieved in DSP all settings are re-settable with
absolute accuracy and in ganged mode parameters track identically. Very narrow
band notch filters (maximum ‘Q’ of 128) can be achieved and unlike analogue filters
these tight ‘Q’ filters are entirely stable. The maximum notch depth is -30dB.
To switch a filter from parametric mode to shelving mode, set the gain of the filter to
0dB and then turn the ‘Q’ control anti-clockwise until ‘HSF’ or ‘LSF’ is displayed.
Now set the frequency and gain as required. To set the filter back to a parametric
section, just ensure that the gain is at 0dB, otherwise the ‘Q’ control will have no
effect.
Note: To show parametric filters in bandwidth (BW) rather than ‘Q’, go
into the ‘System sub-menu’, select ’filter Q or BW’, select BW.
Input Channel Summary Screen
Whilst no adjustments
can be made in this
screen, it displays all the
salient information about
the input section.
The text ‘CHANNEL’ means that this information is about the input channel
processing. (Similarly it would show ‘LIMITER’ when the same screen is selected
during limiter editing).
Beside the ‘CHANNEL’ is ‘A’ – this denotes the input being edited – either ‘A’, ‘B’ or
‘S’ when the channels are stereo ganged. For information about how to stereo gang
modules see the section entitled “Stereo Ganging of Modules” on page 44.
Lastly on the top line, the chosen name for the channel (in this case ‘BACKLINE L’).
This may be selected from a predefined list, or user defined from scratch. For details
of how to select and/or edit the name, see the section entitled “Channel Names” on
page 49.
The bottom line shows, on the left hand side, the name of the last recalled memory
for this module (‘38: VALVE SND’). Recall and storage of memories is dealt with in
detail starting on page 32.
Finally, ‘Expert’ denotes the function mode of this module. The function mode is the
level of editing complexity – ‘Basic’, ‘Normal’ or ‘Expert’. This may be selected as
described in the section entitled “Function Modes” on page 50.
DP324 Operators Manual
Page 15
Audio Function Screens – Dynamic EQ Module
Pressing the key marked ‘DynEQ’ once will display the
first of five possible screens associated with editing the
dynamic equaliser module . The first press will always
display the threshold adjustment. A second press will
display the last selected parameter screen. A third
press will show an overall channel summary, which will be explained below.
Threshold/Ratio Screen
The parameters displayed
on this first screen set the
threshold point for the
dynamic equalisation to
begin. The filter will be
applied to act as either a boost or a cut above or below this threshold. The threshold
may be adjusted over the range of –30dB to +22dB, in 0.5dB steps. The action is set
in the ‘Operating Mode’ screen, explained later in this section. The degree by which
this action is accelerated is controlled by the Ratio parameter. The maximum ratio
available will depend on the operating mode. For ‘Cut Below’ and ‘Boost Above’ and
‘Boost Above’ modes, the ratio has a maximum value of 2:1; for ‘Cut Above’ the
maximum ratio is 4:1. The ‘BYPASS’ key is also active, bypassing the entire module.
Attack/Release Screen
The envelope parameters
are displayed next –
attack and release times
for the action of the
dynamic equalisation.
Attack time covers the range 30uS up to 2.0 seconds. The release time covers the
same range. Note that SIDD will not allow release times to be less than attack times,
due to the likely ‘parameter abuse’ involved and subsequent poor performance.
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DP324 Operators Manual
Dynamic Filter Section
The dynamic filter itself is
next. Remember that
this filter should be
thought of as being two
identical filters – one in
the sidechain listening to the main signal, and one in the main signal path, dynamically
altering its contribution, based on the operating mode and envelope settings. The
frequency and ‘Q’ parameters are the same as those for any filter block, and the
‘MaxG’ parameter sets the ceiling gain of the filter. If, for example, the ‘MaxG’ was
set to +6dB and the operating mode was ‘Boost Above’, then no matter how much
above the threshold the main signal went, the filter could only apply a maximum of
6dB of boost over its selected frequency range. It is variable over a range from 6dB
up to 15dB for ‘Boost’ modes and 18dB for cut modes.
The filter behaviour may be changed from a parametric response to a high or low
shelving filter. However, this adjustment may only be made when the Ratio is set to
1:1. Turning the ‘Q’ control (on rotary 2) fully anticlockwise will select high/low
shelving responses or even full bandwidth, whereupon the dynamic EQ module acts
as a normal compressor or expander, dependant on the operating mode set.
Note: In this module above all others, using the sidechain listen facility is
crucial to the correct implementation of dynamic equalisation. See the
section entitled “Context Aware Sidechain Monitoring” on page 29.
Operating Mode
The operating mode may
only be changed when
the Ratio is set to 1:1.
Four modes are available.
These are:
‘Cut Above’ – when the signal rises above the threshold, the band of frequencies
selected by the D-EQ filter will be progressively reduced in level.
‘Boost Above’ - when the signal rises above the threshold, the band of frequencies
selected by the D-EQ filter will be progressively increased in level.
‘Cut Below’ – when the signal drops below the threshold, the band of frequencies
selected by the D-EQ filter will be progressively reduced in level.
‘Boost Below’ - when the signal drops below the threshold, the band of frequencies
selected by the D-EQ filter will be progressively increased in level.
DP324 Operators Manual
Page 17
Dynamic Equaliser Summary Screen
Whilst no adjustments
can be made in this
screen, it displays all the
salient information about
the D-EQ module.
The text ‘DYNAM EQ’ means that this information is about the dynamic equaliser
module. (Similarly it would show ‘LIMITER’ when the same screen is selected during
limiter editing).
Beside the ‘DYNAM EQ’ is ‘A’ – this denotes the input being edited – either ‘A’, ‘B’ or
‘S’ when the channels are stereo ganged. For information about how to stereo gang
modules see the section entitled “Stereo Ganging of Modules” on page 44.
There may be a lower case ‘x’ displayed beside the channel identifier. This means
that the sidechains of the two dynamic equalisers are linked. This allows their effect
to track perfectly when processing a stereo signal. Linking the sidechains is covered
in the section entitled “Function Linking” on page 45.
Lastly on the top line, the chosen name for the channel (in this case ‘BACKLINE L’).
This may be selected from a predefined list, or user defined from scratch. For details
of how to select and/or edit the name, see the section entitled “Channel Names” on
page 49.
The bottom line shows, on the left hand side, the name of the last recalled memory
for this module (‘4: HF VOX BOOST’). Recall and storage of memories is dealt with in
detail starting on page 32.
Finally, ‘Expert’ denotes the function mode of this module. The function mode is the
level of editing complexity – ‘Basic’, ‘Normal’ or ‘Expert’. This may be selected as
described in the section entitled “Function Modes” on page 50.
What does the metering show?
For the dynamic EQ module,
the three green LEDs marked “6, -3, -1” will show the action of
dynamic EQ when cut is being
applied. Remember that the
amount of cut (or boost) is
dependant not only on the
‘MaxG” parameter (which puts
a limit on how much may be
applied), but also on the ratio
and the actual signal level relative to the threshold.
Similarly, the three LEDs marked “+1, +3, +6” will show dynamically applied boost,
when the operating mode is set to “Boost Below” or “Boost Above”. Under normal
conditions, when the signal has not reached the threshold (from whatever side will
cause dynamic EQ action) there will be no LEDs illuminated.
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DP324 Operators Manual
Audio Function Screens – Noise Gate / Expander Module
Pressing the key marked ‘Gt/Ex’ once will display the
first of seven possible screens associated with editing
the gate or expander module . The first press will
always display the threshold adjustment. A second
press will display the last selected parameter screen. A
third press will show an overall channel summary, which will be explained below.
The screens for the expander will display different parameters in a
few cases, compared to those for the gate. Each channel may be
independently set up to operate as either an expander or a gate. For
details of how to change the behaviour from expander to gate, see
the section entitled “Expander / Gate Option” on page 42.
Threshold/Ratio Screen
The first two parameters
displayed are dependant
on the function mode as
mentioned above. Both
the expander and the
gate have a Threshold
point, which may be set
anywhere in the range –
30dB to +22dB, in 0.5dB
steps. The gate offers
Range as its other parameter – this is the amount of attenuation applied by the gate
when the signal drops below the threshold. So, for example, if a signal was 2dB
below the threshold (which would have caused the gate to close) and the Range was
30dB, it would appear at the output at a level of 32dB below the threshold. It is
variable from 10dB down to 70dB.
The expander displays its Ratio in place of the gate Range – the ratio determines how
severely the signal is attenuated once it drops below the threshold. For example, a
ratio of 2:1 means that if the input drops 10dB below the threshold, the output will
be attenuated to effectively 20dB below. In reality, a ratio of 8:1 or above is severe
enough for the expander to behave in a very similar fashion to the gate. The ratio
may be adjusted from 1.02:1 down to 8:1.
DP324 Operators Manual
Page 19
Attack/Release Screen
The attack and release
times for the expander or
gate are displayed next.
The attack time is defined
at the time for the
expander or gate to reach its full unattenuated level again, once the signal has gone
back over the threshold. It is variable from –60uS (look ahead delay action) up to
500mS. The release time is defined as the time taken for the signal to reach its fully
attenuated state, once the signal drops below the threshold. It is variable from 0.5uS
to 2.5 seconds. Note that SIDD will not allow release times to be less than twice the
attack times, due to the likely ‘parameter abuse’ involved and subsequent poor
performance.
For further details about the negative attack time setting, and
concept of look-ahead delay, see the section entitled “Look Ahead
Delay – Pre-emptive Action” on page 65.
Sidechain High Pass Filter
The first of four filters
available in the sidechain
of the expander/gate is
displayed next. The high
pass filter acts identically
to the one in the main signal path, accessible under the input EQ sections. The high
pass filter may be varied over a frequency range from below10Hz up to 16kHz, in
1/36th Octave steps. Using encoder 3, the response may be switched between
12dB/Octave Bessel to 12dB/Octave Butterworth.
Note that the ‘BYPASS’ key is still active on this screen, but will switch
the gate/expander out of circuit not the filter. The BYPASS text in the
bottom left corner of the screen doesn’t appear, but the ‘ACTIVE’
LED associated with the gate/expander edit key will extinguish.
Sidechain Low Pass Filter
The low pass sidechain
filter may be varied over
a frequency range from
35Hz up to 22kHz, in
1/36th Octave steps.
Using encoder 2, the response may be switched between 12dB/Octave Bessel and
12dB/Octave Butterworth.
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DP324 Operators Manual
Note that, to avoid losing all signal through the sidechain, SIDD will not
allow the high pass filter to be set to a frequency above that of the low
pass filter, and vice versa. For example, this means that it the high pass
was set to 250Hz, the low pass would not extend down to 35Hz, but would stop at
250Hz. This action is irrespective of the bypass settings of the high and low pass. If
you are finding it impossible to get the gate to open, it might be that the sidechain
filters are removing a large percentage of the available energy from the signal. Use
the listen facility to check this. See the section entitled “Context Aware Sidechain
Monitoring” on page 29.
Sidechain Parametric Filters
In addition to the high
and low pass filters, there
are two bands of fully
adjustable parametric EQ
available in the sidechain.
These are designated ‘SIDE 1’ and ‘SIDE 2’ in the bottom left corner of the screen.
Each parametric section can be positioned at a frequency from 20Hz to 20kHz and
features a wide range of 'Q’s to produce response curves ranging from broad to
notch. The gain control ranges from +15dB to -30dB in 0.1dB steps. Frequency steps
are 1/36th Octave resolution for precise control.
To switch a filter from parametric mode to shelving mode, set the gain of the filter to
0dB and then turn the ‘Q’ control anti-clockwise until ‘HSF’ or ‘LSF’ is displayed.
Now set the frequency and gain as required. To set the filter back to a parametric
section, just ensure that the gain is at 0dB, otherwise the ‘Q’ control will have no
effect.
Note: To show parametric filters in bandwidth (BW) rather than ‘Q’, go
into the ‘System sub-menu’, select ’filter Q or BW’, select BW.
DP324 Operators Manual
Page 21
Gate/Expander Summary Screen
Whilst no adjustments
can be made in this
screen, it displays all the
salient information about
the gate/expander
module. The
information shown will
be dependant on the
gate/expander option.
The text ‘GATE’ means that this information is about the gate module. (Similarly it
would show ‘EXPANDER’ as shown when the gate/expander option is set to
expander).
Beside the ‘GATE’ is ‘A’ – this denotes the input being edited – either ‘A’, ‘B’ or ‘S’
when the channels are stereo ganged. For information about how to stereo gang
modules see the section entitled “Stereo Ganging of Modules” on page 44.
There may be a lower case ‘x’ displayed beside the channel identifier. This means
that the sidechains of the two dynamic equalisers are linked. This allows their effect
to track perfectly when processing a stereo signal. Linking the sidechains is covered
in the section entitled “Function Linking” on page 45.
Lastly on the top line, the chosen name for the channel (in this case ‘BACKLINE L’).
This may be selected from a predefined list, or user defined from scratch. For details
of how to select and/or edit the name, see the section entitled “Channel Names” on
page 49.
The bottom line shows, on the left hand side, the name of the last recalled memory
for this module (‘214: NOISE REDN). Recall and storage of memories is dealt with in
detail starting on page 32.
Finally, ‘Expert’ denotes the function mode of this module. The function mode is the
level of editing complexity – ‘Basic’, ‘Normal’ or ‘Expert’. This may be selected as
described in the section entitled “Function Modes” on page 50.
What does the metering show?
In gate or expander mode the 3
LEDs (green/yellow/green)
show level around the threshold
– 12dB below, at threshold, and
12dB above or more from left
to right. In gate mode the two
LEDs marked ‘OPEN’ illuminate
together when the gate opens,
and remain illuminated until the
release phase has begun (i.e.
during any Hold time that has been set.) In expander mode, they can light individually
and show gain reduction of 3dB and 6dB, right to left respectively.
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DP324 Operators Manual
Audio Function Screens – Compressor Module
Pressing the key marked ‘COMP’ once will display the
first of five possible screens associated with editing the
compressor module . The first press will always display
the threshold adjustment. A second press will display
the last selected parameter screen. A third press will
show an overall channel summary, which will be explained below.
Threshold/Ratio/Make-up Gain Screen
The threshold of the
compressor is variable
from –32dB up to
+22dB in 0.5dB steps.
The ratio may be
adjusted from 1.02:1 up to a maximum of 16:1. The application of large amounts of
compression normally necessitates some form of gain compensation, or make-up
gain. Up to 15dB of make-up gain may be applied, in 0.5dB steps, using encoder 3.
Note that the make-up gain is independent of both the input and output gain
parameters. This means that bypassing the compressor may produce a significant
change in level if heavy compression (i.e. a high ratio) has been chosen, and the likely
use of substantial make-up gain.
Attack/Release/Knee Screen
The attack and release
controls determine how
quickly the compressor
reacts to the input signal,
and how quickly it
restores the original level, after the signal has dropped below the threshold again.
The attack time is variable from –60uS (look ahead delay action) up to 152mS. The
release time is variable from 49mS to 3.2 seconds. Note that SIDD will not allow
release times to be less than twice the attack times, due to the likely ‘parameter
abuse’ involved and subsequent poor performance. The ‘Knee’ parameter allows the
onset of compression to be softened – that is then compression will begin at a lower
ratio, below the threshold set, and reach full ratio at the threshold. The knee can be
moved up to 12dB below the threshold – 0dB is ‘hard’, 12dB is ‘soft.
For further details about the negative attack time setting, and
concept of look-ahead delay, see the section entitled “Look Ahead
Delay – Pre-emptive Action” on page 65.
DP324 Operators Manual
Page 23
Sidechain Parametric Filters
There are two bands of
fully adjustable
parametric EQ available
in the sidechain. These
are designated ‘SIDE 1’
and ‘SIDE 2’ in the bottom left corner of the screen. Each parametric section can be
positioned at a frequency from 20Hz to 20kHz and features a wide range of 'Q’s to
produce response curves ranging from broad to notch. The gain control ranges from
+15dB to -30dB in 0.1dB steps. Frequency steps are 1/36th Octave resolution for
precise control.
To switch a filter from parametric mode to shelving mode, set the gain of the filter to
0dB and then turn the ‘Q’ control anti-clockwise until ‘HSF’ or ‘LSF’ is displayed.
Now set the frequency and gain as required. To set the filter back to a parametric
section, just ensure that the gain is at 0dB, otherwise the ‘Q’ control will have no
effect.
Note: To show parametric filters in bandwidth (BW) rather than ‘Q’, go
into the ‘System sub-menu’, select ’filter Q or BW’, select BW.
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DP324 Operators Manual
Compressor Summary Screen
Whilst no adjustments
can be made in this
screen, it displays all the
salient information about
the compressor module.
The text ‘COMPRESS’ means that this information is about the dynamic equaliser
module. (Similarly it would show ‘LIMITER’ when the same screen is selected during
compressor editing).
Beside the ‘COMPRESS’ is ‘A’ – this denotes the input being edited – either ‘A’, ‘B’ or
‘S’ when the channels are stereo ganged. For information about how to stereo gang
modules see the section entitled “Stereo Ganging of Modules” on page 44.
There may be a lower case ‘x’ displayed beside the channel identifier. This means
that the sidechains of the two compressors are linked. This allows their effect to
track perfectly when processing a stereo signal. Linking the sidechains is covered in
the section entitled “Function Linking” on page 45.
Lastly on the top line, the chosen name for the channel (in this case ‘BACKLINE L’).
This may be selected from a predefined list, or user defined from scratch. For details
of how to select and/or edit the name, see the section entitled “Channel Names” on
page 49.
The bottom line shows, on the left hand side, the name of the last recalled memory
for this module (’12: KICK DRUM’). Recall and storage of memories is dealt with in
detail starting on page 32.
Finally, ‘Expert’ denotes the function mode of this module. The function mode is the
level of editing complexity – ‘Basic’, ‘Normal’ or ‘Expert’. This may be selected as
described in the section entitled “Function Modes” on page 50.
What does the metering show?
The group of three LEDs
(green, green, yellow) show
how close the sidechain
signal is to the threshold –
6dB below, 3dB below, and
at the threshold, left to right.
Coupled with these are the
group of four LEDs marked
“GR, 3, 6, 9”. These show
the application of gain
reduction as the signal goes over the threshold – the first LED shows 1dB of gain
reduction.
DP324 Operators Manual
Page 25
Audio Function Screens – Limiter Module
Pressing the key marked ‘LIMIT’ once will display the
first of five possible screens associated with editing the
limiter module . The first press will always display the
threshold adjustment. A second press will display the
last selected parameter screen. A third press will show
an overall channel summary, which will be explained below.
Threshold/Overshoot Screen
The limiter threshold may
be adjusted from –32dB
to +22dB in 0.5dB steps.
Linked to the setting of
the limiter threshold is
the Overshoot parameter. This is not linked to the audio signal path, except for
monitoring purposes, and sets the threshold of the ‘OVSHT’ LED for that channel.
For example, the threshold of the limiter is set to 0dB, and the overshoot threshold is
set to +6.0dB, the ‘OVSHT’ LED will light if the limiter output exceeds the threshold
by 6dB or more. This might happen if the limiter attack time is sufficiently slow so as
to allow fast transients through. The range of monitoring extends from 0dB (i.e.
exactly the same as the limiter threshold) to 12dB above it, in 0.5dB steps.
Attack/Release Screen
The attack and release
controls determine how
quickly the limiter reacts
to the input signal, and
how quickly it restores
the original level, after
the signal has dropped below the threshold again. The attack time is variable from
–60uS (look ahead delay action) up to 152mS. The release time is variable from
49mS to 3.2 seconds. Note that SIDD will not allow release times to be less than
twice the attack times, due to the likely ‘parameter abuse’ involved and subsequent
poor performance. The ‘Knee’ parameter allows the onset of compression to be
For further details about the negative attack time setting, and
concept of look-ahead delay, see the section entitled “Look Ahead
Delay – Pre-emptive Action” on page 65.
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DP324 Operators Manual
Sidechain Parametric Filters
There are two bands of
fully adjustable
parametric EQ available
in the limiter sidechain.
These are designated
‘SIDE 1’ and ‘SIDE 2’ in the bottom left corner of the screen. Each parametric
section can be positioned at a frequency from 20Hz to 20kHz and features a wide
range of 'Q’s to produce response curves ranging from broad to notch. The gain
control ranges from +15dB to -30dB in 0.1dB steps. Frequency steps are 1/36th
Octave resolution for precise control.
To switch a filter from parametric mode to shelving mode, set the gain of the filter to
0dB and then turn the ‘Q’ control anti-clockwise until ‘HSF’ or ‘LSF’ is displayed.
Now set the frequency and gain as required. To set the filter back to a parametric
section, just ensure that the gain is at 0dB, otherwise the ‘Q’ control will have no
effect.
Note: To show parametric filters in bandwidth (BW) rather than ‘Q’, go
into the ‘System sub-menu’, select ’filter Q or BW’, select BW.
DP324 Operators Manual
Page 27
Limiter Summary Screen
Whilst no adjustments
can be made in this
screen, it displays all the
salient information about
the limiter module.
The text ‘LIMITER’ means that this information is about the dynamic equaliser
module.
Beside the ‘LIMITER’ is ‘A’ – this denotes the input being edited – either ‘A’, ‘B’ or ‘S’
when the channels are stereo ganged. For information about how to stereo gang
modules see the section entitled “Stereo Ganging of Modules” on page 44.
There may be a lower case ‘x’ displayed beside the channel identifier. This means
that the sidechains of the two limiters are linked. This allows their effect to track
perfectly when processing a stereo signal. Linking the sidechains is covered in the
section entitled “Function Linking” on page 45.
Lastly on the top line, the chosen name for the channel (in this case ‘BACKLINE L’).
This may be selected from a predefined list, or user defined from scratch. For details
of how to select and/or edit the name, see the section entitled “Channel Names” on
page 49.
The bottom line shows, on the left hand side, the name of the last recalled memory
for this module (’234: PEAK STOP’). Recall and storage of memories is dealt with in
detail starting on page 32.
Finally, ‘Expert’ denotes the function mode of this module. The function mode is the
level of editing complexity – ‘Basic’, ‘Normal’ or ‘Expert’. This may be selected as
described in the section entitled “Function Modes” on page 50.
What does the metering show?
The left hand metering block
shows how close the sidechain
signal is to the threshold of
limiting. The green LEDs show
6dB and 3dB from the
threshold, the yellow LED
(marked ‘L’) on the limit
threshold, and the RED
(marked ‘L+3’) 3dB into
limiting.
As described in the section above, “Threshold/Overshoot Screen”, the ‘OVSHT’ LED
lights when the output of the limiter has gone over the threshold by an amount
determined by the ‘OVSHT’ parameter.
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DP324 Operators Manual
Context Aware Sidechain Monitoring
As with traditional dynamics processors, it is possible to listen to the ‘key’ or
sidechain signal during the setup/editing of any part of SIDD. Rather than add
unnecessary complexity to the front panel with individual keys for sidechain
monitoring of each module, both channels have one key dedicated to the listen
facility. During editing, pressing the ‘LISTEN’ key will route the sidechain from the
module being edited to the output, according to the diagram below. (For safety’s
sake, the output is dropped by 6dB in case excessive boost has been applied using the
EQ.)
The signal for each sidechain path is derived as follows.
Dynamic EQ: The output is taken from the sidechain filter of the dynamic EQ
module. This is a single parametric filter (which may be set to operate as a shelving
filter). Note that the ‘MaxG’ parameter associated with the dynamic EQ module is
not analogous to the gain of a parametric band, and so has no effect on the level
appearing when ‘LISTEN’ is invoked. The input EQ (but not delay, ADT, or
harmonics) will also be included in the sidechain signal.
Expander/Gate: The output is taken from the end of the sidechain filtering associated
with the expander/gate, which encompasses high pass, low pass, and two
parametrics. The effect of any dynamic EQ will also be included in the signal path and
so will affect the threshold setting of the expander/gate, in addition to the input EQ as
before.
Compressor: The output is taken from the second of the two parametric filters in
the compressor sidechain. It will include the effect of the dynamic EQ, input EQ and
the expander/gate, so if there does not appear to be any signal present, the gate may
be closed.
Limiter: The output is taken from the second of the two parametrics included in the
limiter sidechain. It will include the combined contributions of the input EQ, the
dynamic EQ, the expander/gate and the compressor. Additionally, as can be seen
from the diagram, this in the only sidechain monitoring point that includes the delays
and the harmonics.
Input EQ etc.: The output is effectively taken post limiter, but with effect of the
dynamic EQ, expander/gate, compressor, limiter, and delays removed. This is shown
on the diagram by the additional red dashed lines bypassing the dynamics processing,
and the delays.
DP324 Operators Manual
Page 29
Pressing ‘LISTEN’ when no module is being edited will display “NO FUNCTION
SELECTED!” and nothing will happen. Selecting a module for editing and then
pressing ‘LISTEN’ will cause the ‘LISTEN’ LED to flash in time with the corresponding
modules ‘EDIT’ LED.
Listen may be cancelled by pressing it again,
selecting another module to edit, or pressing
‘QUIT’ which will also quit the editing
procedure.
Note: If pressing ‘LISTEN’ does not appear to have any effect, it is
probably because of the ‘Output Mode’ setting. The ‘Listen’ routing can
be set to appear on the auxiliary outputs instead of the main outputs.
See the section entitled “Channel Routing” on page 48.
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DP324 Operators Manual
The Menu System
The menu system is arranged as shown in the tree diagram below.
Enter the Main Menu level
by pressing the ‘MENU’
key once.
Navigate to the required
sub-menu using the BACK
and NEXT keys.
Enter the menu by pressing
ENTER.
Navigate to the required
function using the BACK
and NEXT keys.
Select the function by
pressing ENTER again.
Most functions require
ENTER to be pressed to
confirm selection, such as
changing the
Expander/Gate option;
QUIT can always be
pressed to cancel the
current function and return
to the default screen. The
unit automatically exits
from the menu system
after approximately twenty
seconds of inactivity.
Note:
Pressing
MENU twice
from the default screen will
jump to the last selected
menu function for faster
access.
DP324 Operators Manual
Page 31
Memory Sub-menu
The functions available in the Memory Sub-menu are as follows.
Recall a Preset
Recall a User Memory
Preview a Preset
Preview a User Memory
Store a User Memory
Erase a User Memory
Load Memories < PC Card
Save Memories > PC Card
User Memory Resources
Choose an appropriate tool from the library of
available presets as a starting point
Choose settings previously created by a user for a
particular purpose
Listen to available library settings before committing
to a recall and overwriting current settings
Listen to previously created settings before recalling
and overwriting current settings
Commit a preferred configuration to memory for
later use
Clear a configuration to free up space if memory
resources become low
Backup currently stored configurations with new set
from a PCMCIA card
Copy all stored configurations onto a PCMCIA card
for archiving purposes
Find out how many memories are free and what
percentage of space is left
Memory Configurations and Presets – How Are They Organised?
In order to increase SIDD’s flexibility, each module may have its settings stored (or
recalled) individually, or an entire channel may be stored (or recalled) at once. This
will allow, for example, a preferred compressor setting to be recalled into the signal
path after the input EQ has been set up, or the limiter introduced.
Prior to any access to memories, the type of memory must be selected be it a
complete channel, or an individual module. From this point on, only memories of this
type are displayed in the available list.
Presets are stored in non-volatile memory and are a valuable resource of useful
settings for many applications. They are pre-loaded into the unit and cannot be
overwritten, although they may be adapted if necessary to suit a particular
application. The changed version may then be stored in a user memory.
There are 256 memory locations available within SIDD. These may
contain any module’s settings, or a complete channel’s worth,
although a complete channel will take up several memory slots
resources. Remember, if the memory gets too full, the entire memory set can be
copied onto a PCMCIA card for safe keeping, and the internal memory cleared and
used again. See the section entitled “Saving Memories to a PC Card” on page 39.
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DP324 Operators Manual
Recalling a Preset or a User Memory
As the sequence of events for recalling presets and user memories is virtually
identical, both will be dealt with in this section.
Selecting the memory sub-menu and then either
Recall a Preset
or
Recall a User Memory
will prompt for the choice of what type of memory is to be recalled. As explained in
the previous section this will be one of the following choices:
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
=
=
=
=
=
=
=
=
=
=
=
=
[A]Complete Chan.
[B]Complete Chan.
[A]Input EQ etc.
[B]Input EQ etc.
[A]Dynamic EQ
[B]Dynamic EQ
[A]Expander
[B]Gate
[A]Compressor
[B]Compressor
[A]Limiter
[B]Limiter
The Input EQ etc. selection refers to all the processing that may be edited under
the input EQ section. This will include the delays, the EQ, the harmonics generator,
and the input and output gains.
Note that the memory type for the selection of gate or expander
will depend on the current configuration of the gate/expander
module for that channel. If a channel is configured as a gate, then
only gate memories will be offered. Each channel may be
independently set up to operate as either an expander or a gate. For details of how
to change the behaviour from expander to gate, see the section entitled “Expander /
Gate Option” on page 42.
Press ENTER to confirm the selection of the type. The screen will show
Recall[A]Compressor
234:Memory Name
and either turning encoder 3 or using the BACK and NEXT keys will scroll through
the list of available memories of this type. Press ENTER once to select the memory.
A second press is required to confirm and complete the memory recall.
Pressing QUIT at any time will return the unit to the default screen and exit the
entire recall process.
DP324 Operators Manual
Page 33
Previewing a Preset or a User Memory
The preview feature allows memories to be sequentially loaded into the audio path
without going through the entire recall procedure every time. This allows for quick
comparisons to be made between memories, and failsafe confirmation of the settings
prior to the recall. Note that the settings loaded for any particular module are not
previewed in isolation – the rest of the signal path’s contribution will still be audible.
So, for example, if a compressor is being previewed, any input EQ, gate, dynamic EQ,
or limiter modules already in use will still be heard.
As the sequence of events for previewing presets and user memories is virtually
identical, both will be dealt with in this section.
Selecting the memory sub-menu and then either
Preview a Preset
or
Preview a User Memory
will prompt for the choice of what type of memory is to be previewed. This will be
one of the following choices:
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
=
=
=
=
=
=
=
=
=
=
=
=
[A]Complete Chan.
[B]Complete Chan.
[A]Input EQ etc.
[B]Input EQ etc.
[A]Dynamic EQ
[B]Dynamic EQ
[A]Expander
[B]Gate
[A]Compressor
[B]Compressor
[A]Limiter
[B]Limiter
The Input EQ etc. selection refers to all the processing that may be edited under
the input EQ section. This will include the delays, the EQ, the harmonics generator,
and the input and output gains.
Note that the memory type for the selection of gate or expander
will depend on the current configuration of the gate/expander
module for that channel. If a channel is configured as a gate, then
only gate memories will be offered. Each channel may be
independently set up to operate as either an expander or a gate. For details of how
to change the behaviour from expander to gate, see the section entitled “Expander /
Gate Option” on page 42.
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DP324 Operators Manual
Press ENTER to confirm the selection of the type. The screen will show
Preview[A]Compressor
234:Memory Name
and the setting appropriate to this module’s memory will be loaded into the signal
path and become immediately audible.
Remember - pressing QUIT at any time will return the unit to the
default screen and exit the entire preview process, restoring the
original settings immediately.
Now, either turning encoder 3, or using the BACK and NEXT keys will scroll through
the list of available memories of this type. Each one will become audible in turn.
Press ENTER to permanently recall the memory. Note that there is no confirmation
stage in preview mode.
Let SIDD select the memory type for you!
In any memory mode, storing, recalling or previewing – SIDD selects the most likely
type of memory you will use based on the module that you are editing. Rather than
have to choose the memory type and channel from the list every time, SIDD will start
you in the appropriate point in the list, leaving you to just press ENTER to confirm
the type selection, or change it yourself.
Knowing how SIDD does it makes the memory access even simpler.
If you are currently editing a module, for example the compressor for channel A,
press MENU, and access a memory function, SIDD will select
TYPE = [A]Compressor
in any memory menu that calls for a type selection to be made.
If you are editing a particular module, but want to quickly select a complete channel
to be saved, press QUIT to end the editing session before pressing MENU and
selecting the menu function. SIDD will then choose
TYPE = [A]Complete Chan.
based on the complete channel type based on the last channel you edited.
If you are not editing at all, pressing MENU and selecting a memory function will
always select
TYPE = [A]Complete Chan.
i.e. the start of the list of possible memory types.
Remember - pressing MENU twice from the default screen will jump to
the last selected menu function for faster access.
DP324 Operators Manual
Page 35
Storing a User Memory
Selecting the memory sub-menu and then either
Store a User Memory
will prompt for the choice of what type of memory is to be stored. This will be one
of the following choices:
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
=
=
=
=
=
=
=
=
=
=
=
=
[A]Complete Chan.
[B]Complete Chan.
[A]Input EQ etc.
[B]Input EQ etc.
[A]Dynamic EQ
[B]Dynamic EQ
[A]Expander
[B]Gate
[A]Compressor
[B]Compressor
[A]Limiter
[B]Limiter
The Input EQ etc. selection refers to all the processing that may be edited under
the input EQ section. This will include the delays, the EQ, the harmonics generator,
and the input and output gains.
Press ENTER to confirm the selection of the type. The screen will show
Store[A]Compressor
234:Memory Name
allowing selection of the memory location to store into. If the memory already has
been used, a name will appear. If the memory is currently unused, then the screen
will show
Store[A]Compressor
145: {empty}
Press ENTER to confirm the selection of the location to use. At this stage, the name
of the memory may be edited, or generated from scratch in the case of an empty
location. The screen shows
Name Memory…
145:XTA ROCK
with a cursor appearing under the first character of the name. Use encoder 1 to
select the character, and the BACK and NEXT keys to move along the name. When
satisfied with the name, press ENTER to complete the store procedure. Note that
the name does not have to be edited – the last stored name will be kept if ENTER is
pressed immediately after choosing the location. If the location was empty, then a
completely blank name will be stored.
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DP324 Operators Manual
Erasing a User Memory
Selecting the memory sub-menu and then either
Erase a User Memory
will prompt for the choice of either an individual memory
Erase a User Memory
->
Erase a User Memiory. . .?
or all user memories
Erase a User Memory
->
Erase ALL User Memiories.?
Press ENTER to confirm the selection of the type. If an individual memory has been
chosen, the screen will show
Select A Memory to Erase
234: Vocal EQ Set One
allowing selection of the memory location to erase. Use encoder 3 to choose.
Press ENTER to confirm the selection. The screen shows
Erase this Memory. . .?
Press [ENTER] to Confirm
A second press is required to confirm and complete the memory erase.
Selection of ALL memories will show
Erase ALL User Memories. . .?
Press [ENTER] to Confirm
Two presses of ENTER will now erase all memories.
Pressing QUIT at any time will return the unit to the default screen and exit the
entire recall process.
DP324 Operators Manual
Page 37
PCMCIA Cards – What can they be used for?
PC cards, or PCMCIA cards, to give them their full
title, may be used to store several types of data for
use with SIDD. These are:
Memory Set Back-ups
Preset Library Updates
Software Updates
Unit Clone Data
The type of card that SIDD uses is a
PCMCIA Type I Card, 256Kb or greater; SRAM.
XTA can supply you with these cards – the part
number is OPT-PC1.
Cards bigger than 256Kb in size may be used, but SIDD will only use the first 256K
(i.e. the first 25% in the case of a 1Mb card.) In many cases, it is actually cheaper to
buy the larger cards, rather than the smaller sizes.
It’s worth noting that a card can’t store more than one type of data at a time, with the
exception of memory sets and clone data. Four complete memory sets and one set
of clone data may be stored on a single card. However, software updates/preset
files/memory sets may not exist on the same card.
The memory on the card is kept alive by a lithium cell built into the card itself. This
has an average life of approximately five years. SIDD will warn you if you insert a card
with a battery that is low or flat. The battery should be carefully removed and
replaced as soon as possible. Most cards only allow for ten minutes or so of
unassisted backup, so be sure to have the new battery to hand when removing the
old one.
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DP324 Operators Manual
Saving Memories to a PC Card
Saving memories to a PCMCIA card will copy the entire memory set onto the card,
erasing whatever was previously stored on the card if it was a different type of data
(as described in the previous section). Four (4) memory sets may be saved on the
same card – along with a set of clone data if required.
Selecting the memory sub-menu and then
Save Memories > PC Card
will prompt for the insertion of a suitable card into the slot below the encoders, if one
has not already been inserted. The card will only go in one way. Make sure the
‘Write Protect’ switch on the back right hand corner (as seen from the fitted position)
is set to ‘Off’. SIDD will warn you if the card is protected.
The screen will then show
Save Memories > PC Card
1: Memory Set Name
Use encoder 3 to choose the location on the card for the memory set to be saved –
this may be over another previously saved set, or a new one. SIDD will warn you if
you are about to overwrite a previously saved memory set. Press ENTER to confirm
the choice of location. The screen will show
Name Memory Set…
1: Memory Set Name
with a cursor appearing under the first character of the name. Use encoder 1 to
select the character, and the BACK and NEXT keys to move along the name. When
satisfied with the name, press ENTER to complete the save procedure. Note that
the name does not have to be edited – the last saved name will be kept if ENTER is
pressed immediately after choosing the location. If the location was empty, then a
completely blank name will be stored.
NOTE: It is crucial that the ‘Write Protect’ switch on the card is set
back to the ‘On’ position before the card is removed from the unit.
Data corruption and loss of all the information on the card may
result if this is not done!
If all four memory locations on the card have been used, SIDD will warn you and
prompt for you to choose one of the locations to overwrite. If you don’t want to
overwrite any of them, press QUIT, insert a blank card, and start again.
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Loading Memories from a PC Card
Note: Before loading memories from a PC Card, note that the
entire memory contents already present in SIDD will be
overwritten. This is the case even if the memory set contains fewer
memory locations, or only locations currently unused.
Selecting the memory sub-menu and then
Load Memories < PC Card
will prompt for the insertion of a suitable card into the slot below the encoders, if one
has not already been inserted. The card will only go in one way. If the wrong type of
card is inserted (such as a clone card or program update card), SIDD will warn you
with a message.
Assuming the card is of the correct type, the screen will show
Load Memories < PC Card
1: Name of Memory Set
Use encoder 3 to choose the location on the card of the memory set to be loaded.
Press ENTER to confirm selection. The screen will show the name of the chosen set,
and require a further press of ENTER to confirm the loading of the chosen set.
User Memory Resources
As described in the previous section “Memory Configurations and Presets – How Are
They Organised?” on page 32, there are 256 available memory locations in SIDD. The
dynamic allocation of memory to these locations depends on what is stored in each.
Obviously a complete channels worth on data will take up more space than just a
limiter modules settings. Sixty (60) complete channel memories can be stored.
With this in mind, selecting the memory sub-menu and then
User Memory Resources
will display
User Memmory resources
Free Memories = 225 (89%)
If the memories are mainly complete channels worth of data, then the percentage of
free memory will be much lower than if only modules at a time have been stored.
Half the locations being free will not mean 50% of the memory is free. If you are
getting short on memory, either copy the entire memory onto a PC card(see page
39), or erase some memories you no longer need (see page 37).
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DP324 Operators Manual
Configuration Sub-menu
The functions available in the Configuration Sub-menu are as follows.
Expander / Gate Option
Stereo Ganging
Function Linking
Channel Routing
Channel Names
Function Modes
Set whether the mode of the expander/gate module
on each channel.
Set parameter ganging on each module corresponding
one on other channel
Set sidechain linking on each module with
corresponding module on other channel
Enable one channel to be used as an external
sidechain input to the other and…
Select routing of listen signal, aux delay output and
main gain position in signal path
Name each channel from a list or create name from
scratch
Select the level of editing complexity available for
each module
Global or Individual Settings
Many of the options in this menu initially ask the question
Set Globally?
This is a shortcut that allows all the relevant modules to be configured identically in
one operation. This proves useful in cases where a function needs to be cleared on
all modules simultaneously. If it is required to set each module separately, select
Set Individually?
Using either encoder 3 or the BACK/NEXT keys. Press ENTER to continue.
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Expander / Gate Option
Both channels may have their expander/gate module configured independently to
operate as either a noise gate or an expander. The parameters available for each
module during editing are dependant on this setting, with gates and expanders being
treated as completely separate dynamics processors as far as memories are
concerned.
Selecting the configuration sub-menu and then
Expander / Gate Option
will show the current mode of the two channels of the unit. This is self-explanatory,
and will be one of the four following. Note that the asterisk next to one selection
indicates the current format.
Mode: A = Gated, B = Gated
Mode: A = Expand, B = Gated
Mode: A = Gated, B = Expand
Mode: A = Expand, B = Expand *
Use encoder 3 to choose a different configuration, and press ENTER. The screen will
display
Format Modified!!
Press [ENTER] to Confirm
Pressing ENTER again will, after a short delay, change the format and return to the
default screen.
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DP324 Operators Manual
What is the Difference Between Stereo Ganging and Function Linking?
These two terms are easily confused and justify a section explaining what each means
before dealing with the options themselves.
On a traditional dynamics processor, if it has at least two channels, there is often the
ability to ‘slave’ one channel to the other. Under these circumstances the left hand
channel normally becomes the ‘master’. The parameter controls for the ‘slave’
channel become redundant with both channels assuming the parameter settings of
the master channel.
Stopping at this point – this is what the ‘Stereo Ganging’ on SIDD accomplishes. The
parameters are linked from one channel to the other, so that any adjustment of one
module will set the same parameter on the other channel’s module to an identical
value. Adjustments are absolute – that is no offset will be maintained between the
same parameter on each module. If, for any reason, an offset is required gang the
modules, set the one channel, then ungang and introduce the offset value.
Parameters
will only
assume the
same value
once they
have been adjusted in the stereo gang mode. For this reason, it is best to enable the
stereo ganging prior to any editing to ensure all parameters are the same. Once any
module has been ganged, either EDIT key may be used for editing. Both EDIT LEDs
will illuminate. Note that the STEREO LED will only illuminate if all the modules are
ganged. The LISTEN function always remains independent even if entire channels are
linked.
Considering the traditional dynamics processor again – pressing the ‘Stereo’ or ‘Slave’
button not only links the controls on the front panel, but connects the sidechains of
the two channels internally. The reason for this is to maintain the same degree of
processing on both channels when treating a stereo signal. So, for example, if in the
case of a stereo limiter arrangement, one channel begins to limit by 3dB, the same
amount of limiting will be applied to the other channel. This prevents shifts in the
stereo image that would occur if the level dropped in one channel but not the other.
Stereo ganging is also
indicated on each
modules summary
information screen – the
channel ID changes from
‘A’ or ‘B’ to ‘S’ for stereo.
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SIDD’s function linking option allows the sidechains of each module to be linked to
maintain stereo image integrity. Each module can be linked independently, so that,
for example, limiters may be linked but compressors stay independent. Function
linkage is indicated on the
relevant module’s
summary information
screen, by an “x” with a
bar over it, like this.
Summarising the difference between the two functions:
Stereo Ganging Links Parameters
Function Linking Links Sidechains.
Stereo Ganging
Selecting the configuration sub-menu and then
Expander / Gate Option
will ask the question mentioned earlier about global or individual setting of the
modules. Use encoder 3 or the BACK/NEXT keys to choose global or individual.
Press ENTER to proceed.
If the gangs are to be set globally, the screen will show
Stereo Ganging
Set Stereo Ganging: ON*
Choose ON or OFF and press ENTER to confirm choice. The unit will request a
further press of ENTER before setting all the stereo gangs, and returning to the
default screen.
If the gangs are to be set individually, the screen will show
Stereo Ganging
Input Ganged = NO*
Selecting YES or NO and pressing ENTER will proceed through the Dynamic EQ,
Gate/Expander, Compressor and Limiter, finally returning to the default screen.
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DP324 Operators Manual
Function Linking
Selecting the configuration sub-menu and then
Function Linking
will go through each module in turn – select ‘Linked’ or ‘Not Linked’ as required.
Note that the Dynamic EQ module is slightly different. It offers three choices Function Linking
DynamicEQ1: No Linking
Function Linking
DynamicEQ1: Linked High
Function Linking
DynamicEQ1: Linked Low
These refer to the way the linkage will operate. If ‘Linked High’ is chosen, then the
channel with the highest sidechain signal over the threshold will determine the
amount of dynamic EQ compression or expansion applied. If ‘Linked Low’ is chosen,
the converse will be true – the channel with the lowest sidechain signal over the
threshold will determine the amount of dynamic EQ compression or expansion
applied.
For all the other modules, the choice is simply ‘Linked’ or ‘No Linking’. The sidechain
with the highest signal over the threshold will determine the gain reduction applied to
both.
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SIDD’s Configurations
To facilitate use in as many situations as possible, SIDD may be configured to operate
in several different ways. The amount of processing and overall order of the main
modules does not change, but the routing of the ADT module, and the ‘Listen’ signal
may be altered.
Configuration 1: A.D.T. Format; Gain Pre-Limiter; Listen on Mains
In this configuration, the separate delay line with gain control is set up to operate as
an auto double tracking module, which is routed back into the main signal path. This
allows for ‘thickening’ effects to be applied to the main signal after the majority of the
dynamics processing. The gain control is pre-limiter so that the limiter can be set to
operate as a ‘brickwall’ device, not allowing any signals above its threshold to pass
through. Any gain applied with the output gain control effectively moves the signal
nearer the limiter threshold. The ‘listen’ signal will appear in place of the main signal
when ‘LISTEN’ is pressed during editing of any module.
Configuration 1I: A.D.T. Format; Gain Post-Limiter; Listen on Mains
In this configuration, the main gain control is just after the limiter, so that adjusting the
gain will increase the level at the outputs, but not affect the limiter threshold. The
ADT module is the same, and the listen signal still gets switched into the main signal
path when ‘LISTEN’ is pressed.
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DP324 Operators Manual
Configuration 11I: A.D.T. Format; Gain Pre-Limiter; Listen on Auxes
In this configuration, the main gain control is just before the limiter, with the ADT
module as before. However, the listen signal now gets switched through to the
auxiliary outputs when ‘LISTEN’ is pressed, so the main signal path is not interrupted.
This allows independent monitoring of any sidechain signal during editing.
Configuration 1V: A.D.T. Format; Gain Post-Limiter; Listen on Auxes
In this configuration, the main gain control is after before the limiter, with the ADT
module as before. The listen signal is again routed to the auxiliary outputs when
‘LISTEN’ is pressed.
Configuration V: Split Format; Gain Post-Limiter; Listen on Mains
In this configuration, the main delay is moved to the post-limiter position, and the
ADT delay, is routed to the auxiliaries. Pressing ‘LISTEN’ will interrupt the main
signal path and switch in the sidechain signal, leaving the auxiliaries untouched.
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Configuration Menu cntd. : Channel Routing
The channel routing deals with not only the configuration setup described in the last
section, but also the sidechain source for the entire channel.
Selecting the configuration sub-menu and then
Channel Routing
will start by asking for the sidechain source for each channel:
Input Routing
Channel A Source: A+B*
Choosing ‘B’ for channel A’s source effectively makes channel B the external sidechain
input for channel A. This might prove useful if, for instance, the gate was being used
to trigger a bass guitar main signal, keyed from the bass drum microphone. It is also
possible to mix the two channels sidechains together – the ‘A+B’ option effectively
performs the same function as setting all the Function Linking options on.
Press ENTER to confirm selection and proceed.
After choosing the input sources for the sidechains, the output mode must be set.
This will either be ‘ADT’ or ‘SPLIT’. The screen will show
or
Output Mode
Output Mode = ADT*
Output Mode = SPLIT
Choosing SPLIT and pressing ENTER will conclude the routing options and SIDD will
ask for one final press of ENTER before updating the configuration. The outputs will
mute for a couple of seconds whilst this happens.
Choosing ADT will then proceed to the choice of limiter position.
or
Output Mode
Limiter Posn = Post Gain
Limiter Posn = Pre Gain*
Finally, the choice of routing the listen signal via the auxiliaries or the main outputs is
offered.
or
Output Mode
Listen Outputs = Main
Listen Outputs = Auxes*
One final press of ENTER will update the complete configuration. Again, the outputs
will mute for a couple of seconds whilst this happens.
Remember - pressing QUIT at any time will return the unit to the
default screen and exit the entire configuration process: no changes
take effect until all the settings have been selected.
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DP324 Operators Manual
Channel Names
The channel name
appears on the default
screen after the unit has
finished waking up, as
well as being displayed as
part of each module’s
summary information
screen.
Selecting the configuration sub-menu and then
Channel Names
will ask which channel to name. Choose the channel and press ENTER. SIDD
contains a list of predefined names covering a large number of applications. These
are designed to save the time and effort of typing one in by hand. If required, a name
can be created from scratch. Once used, it will subsequently appear as part of the list
of predefined names, allowing it to be reused again at a later stage.
Having selected the channel, the screen will show
Channel Names
Select Predefined List*
Encoder 3 can be used to change this to
Channel Names
Select User Edit*
Dealing with the predefined list first, selecting it and pressing ENTER will then display
Channel Names
Select 51:BACKLINE L :
With encoder 3 being used to scroll through the list. Press ENTER to confirm
selection of the new name.
If the user edit option was chosen, a cursor appears under the first character of the
name (whatever that currently is set to).
Channel Names
Edit Name: _ACKLINE R :
The BACK and NEXT keys move along the name and encoder 3 chooses the
character. Press ENTER when finished editing, and to accept the new name.
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Function Modes
To simplify editing in high-pressure situations, or to hide certain parameters from
user tampering, SIDD has three levels of editing complexity, known as the function
modes. These are designated ‘Expert’, ‘Normal’, and ‘Basic’.
The differences between each mode are explained in the tables below. The most
comprehensive mode – ‘Expert’ – gives access to all the editable parameters of a
module. ‘Normal’ mode dispenses with the less used features. ‘Basic’ mode offers
only a single parameter screen showing only the most important parameter(s).
Expert Mode
Input/Output Gain
Main Delay
ADT/Split Delay
Harmonics
High Pass Filter
Low Pass Filter
Parametric Filters x 6
Expert Mode
Threshold
Ratio
Attack
Release
Dynamic Filter
Operating Mode
Expert Mode
Threshold
Ratio (Range)
Attack
(Hold)
Release
Sidechain HPF
Sidechain LPF
Sidechain PEQ x 2
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Input EQ. etc.
Normal Mode
Input/Output Gain
Main Delay
ADT/Split Delay
Basic Mode
Input/Output Gain
Main Delay
High Pass Filter
Low Pass Filter
Parametric Filters
High Pass Filter
Low Pass Filter
Parametric Filters
Dynamic EQ
Normal Mode
Threshold
Ratio
Basic Mode
Threshold
Dynamic Filter
Dynamic Filter
Expander Gate (Gate Mode)
Normal Mode
Basic Mode
Threshold
Threshold
Ratio (Range)
Ratio (Range)
Attack
(Hold)
Release
Sidechain HPF
Sidechain LPF
DP324 Operators Manual
Expert Mode
Threshold
Ratio
Make-up Gain
Attack
Release
Knee
Sidechain PEQ x 2
Expert Mode
Threshold
Overshoot
Attack
Release
Sidechain PEQ x 2
Compressor
Normal Mode
Threshold
Ratio
Make-up Gain
Attack
Release
Knee
Limiter
Normal Mode
Threshold
Overshoot
Attack
Release
Basic Mode
Threshold
Ratio
Make-up Gain
Basic Mode
Threshold
The current function
mode for any module is
shown during editing, on
the module summary
information screen.
Selecting the configuration sub-menu and then
Function Modes
will ask the question mentioned earlier about global or individual setting of the
modules. Choose global or individual and press ENTER to proceed.
If the gangs are to be set globally, the screen will show
Function Modes
All Functions = Expert*
Choose level of editing complexity and press ENTER to confirm choice.
If the gangs are to be set individually, the screen will show
Function Modes
[A]Input EQ = Expert*
Choose level of editing complexity and press ENTER to proceed through the
Dynamic EQ, Gate/Expander, Compressor and Limiter.
Note that parameters set up and then hidden by entering a simpler
editing mode remain in effect – they are just inaccessible.
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Security Sub-menu
Please read the entire section about locking/unlocking the unit before
entering the security menu, as an inadvertent lockout may require a call
to XTA, and we’re not here 24 hours a day!
The security system built into SIDD is designed to prevent any unwanted tampering
with the front panel, via the use of a four character code.
Locking the Unit
Selecting the security sub-menu and then
Security Sub-Menu
will offer the single option to lock the unit:
Unit Security Menu:
Lock Unit
Pressing ENTER will then ask for the entry of a lock code. The module editing keys
come into play at this point, representing the set of possible letters/numbers that may
be used. The diagram below shows how the keys map to their respective characters.
It is simply a case of typing in the required code using the keys, and then confirming
the code by typing it in again. If the confirmation if wrong, the unit will not lock.
Assuming the code has been confirmed, all editing will have been disabled. It is still
possible to view all the parameters of each module by pressing the module edit keys,
and scrolling BACK and NEXT through the parameters.
Any attempt to adjust a parameter, bypass a function or enable the sidechain listen
will display the message
!! Unit is Locked !!
Unlocking the Unit
Pressing the MENU key when the unit is locked will display the message
Enter Code TO. . .
Unlock Unit [
]
Use the module editing keys to re-enter the code previously used to lock the unit.
The unit will unlock upon the entry of the last code character. There is no limit to
the number of times the password may be entered incorrectly.
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DP324 Operators Manual
Forgotten the Code?
If you forget the code used to lock your unit, it is still possible to unlock it by entering
the master code. By default, this is ‘AABB’ on all units as they leave the factory.
However, realising that this code may quickly become common knowledge, it is
possible to change this master code to a user defined one.
The procedure is as follows:
Turn on the unit with the ENTER key held in.
After running through the start-up procedure, the unit will display
Enter Master Key :
[
]
Enter the code ‘AABB’ using the module edit keys.
The unit will then display
Enter New Master Key :
[
]
Enter a new four digit code to replace the current master code.
You will be asked to re-enter the code for confirmation – after doing so the message
New Master Key is SET
will be displayed, and the unit will then start as normal. From now on, the new
master code may be used to override the lockout on the unit.
If the security override code has been changed from the default
‘AABB’, you will have to contact XTA after invoking the following
procedure:
Turn on the unit with the MENU key held in.
After running through the start-up procedure, the unit will display
Enter Set-Up Code:
[
]
Enter the code ‘8713’ using the module edit keys.
The unit will then display
Enter XTA Supplied Code:
Break Code = XXXXX [
]
and note the ‘XXXXX’ encrypted code.
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Page 53
Ring XTA and quote the code – we will give you the complimentary break code.
This code will need to be entered at the above stage to reset the master reset to
‘AABB’.
The unit may then be unlocked using ‘AABB’ as required.
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DP324 Operators Manual
System Sub-menu
The functions available in the Configuration Sub-menu are as follows.
System Status Info.
LCD Contrast
LED Brightness
Program Update
Preset Update
Wake-up Time
Filter Q or BW
Delay in Time/Distance
Meter Operational Mode
Unit Cloning
Display temperature log and service data
Adjust viewing angle of the display
Adjust brightness of metering
Install new software via PCMCIA card
Install new presets via PCMCIA card
Adjust time after power-up before audio enabled
Change parametric filter width units
Change delay units readout
Disable meters when module bypassed
Store/Recall all memory & options via PCMCIA card
System Status Information
Selecting the system sub-menu and then
System Status Info.
Will automatically begin to scroll through a variety of data relating to the operating
state of the unit. This is listed in the table below.
Display Shows…
===System OK===
==Audiocore Series==
DP324 SIDD
===Software V1.70==
XTA Presets V000
Numeric Code: 1395
Firmware No.: 268
Stack Probe: 74
Current Temper. = 23’C
Maximum Temper. = 26’C
Max Ever Temper. = 45’C
This means…
No following status information is invalid…
Unit is part of Audiocore series of processors
Model number and name
Current software version
Current preset library version
Software version’s revision sub-code
Units audio/host processor hardware revision
Host processor program health
Units internal temperature now
Units internal temperature since powered up today
Maximum temperature ever attained
LCD Contrast
Selecting the system sub-menu and then
LCD Contrast
will allow adjustment of the viewing angke of the display, from its default setting of 0
through to 100. Use encoder 3 to adjust.
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Page 55
LED Brightness
Selecting the system sub-menu and then
LED Brightness
will illuminate all the LEDs and allow adjustment of the brightness, from 0, through its
default setting of 8, to 15. Use encoder 3 to adjust.
Program Update
The operating system software may be updated from a PCMCIA card.
SIDD will warn you if
you try to load an older version than is currently running
you try to load from a card that contains the wrong type of data
you try to load from a blank or corrupted card
Selecting the system sub-menu and then
Program Update
will prompt for the insertion of a PCMCIA card containing the new version of
software. After inserting a card, press ENTER. The display will show
Loading New Software
Erasing Flash
followed by
Loading New Software
Block nnnn OF 2046
The number ‘nnnn’ will increment until the load is finished. SIDD will reboot when
finished. During the process, the meters will freeze and there will be no audio. The
entire process, from pressing ENTER until the re-boot, should take no longer than
one minute.
During the program update do NOT switch off or disturb the
power connection to the unit! The software will become
irretrievably corrupted if this happens, the unit inoperable,
and your memories may be erased!
Contact XTA if this happens for details on how to reboot your unit and avoid losing
your memory settings.
If the program card is inserted before MENU is pressed, the menu
system is bypassed and jumps to the update function directly.
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DP324 Operators Manual
Preset Update
A new library of presets may be loaded from a PCMCIA card in exactly the same
manner as a software update is loaded.
Selecting the system sub-menu and then
Preset Update
will prompt for the insertion of a PCMCIA card containing the new preset file. After
inserting a card, press ENTER. The display will show
Preset Update
Loading Presets
The unit will reboot after the load process has completed.
Wake-up Time
This is the countdown timer that appears after the unit is powered up, prior to the
audio fading up. The time is adjustable in ten second increments from zero, to sixty
seconds .
Selecting the system sub-menu and then
Wake-up Time
will display
Wake-up Time
Wake-up Time: 20 Secs *
Use encoder 3 to select the required time and press ENTER to confirm selection.
Filter Q or Bandwidth (BW)
The readout of units for the parametric filter width may be swapped between ‘Q’ (a
unitless value) and bandwidth (in octaves). ‘Q’ is simply the reciprocal (i.e. ‘one
over’) of the bandwidth.
Selecting the system sub-menu and then
Filter Q or BW
will display
Filter Q or BW
Filter Mode:
BandWdth *
Use encoder 3 to select the required time and press ENTER to confirm selection.
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Delay in Time/Distance
The readout units of the main delay and ADT/split delay may be changed from
milliseconds to either feet or metres.
Selecting the system sub-menu and then
Delay in Time/Distance
will display
Delay in Time/Distance
Display in : Time (mS)*
Use encoder 3 to select ‘Time
selection.
(mS)’, ‘Metres’
or ‘Feet’. Press ENTER to confirm
Meter Operational Mode
To minimise the possibility of confusion during high pressure live situations, SIDD’s
Meters can be set to only operate when the relevant module is in circuit. This cuts
down on the number of LEDs illuminated and makes it easier to see exactly how
much processing is being applied at any given time.
Selecting the system sub-menu and then
Meter Operational Mode
will display
Meter Operational Mode
Meters Off in Bypass *
Use encoder 3 to select ‘Meters Off
Press ENTER to confirm selection.
in Bypass’
or ‘Meters
Always Active’.
Note that the ‘OPEN’ LEDs associated with the expander/gate will
always illuminate when ‘BYPASS’ is pressed, as the gate/expander is
effectively opened. Input and output metering cannot be disabled
under any circumstances.
Unit Cloning
To configure one unit identically to another, the quickest way is with the cloning
function. This copies all memories, the current audio settings and all menu options,
with the exception of the remote interface settings and security settings. Once
written to a PCMCIA card, this card may be used to replicate the settings on any
number of units making them audibly and operationally identical to the original.
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DP324 Operators Manual
Storing Clone Data:
Selecting the system sub-menu and then
Unit Cloning
will prompt for the insertion of a PCMCIA card. After inserting a card, press ENTER.
The display will show
Unit Cloning
Make a Clone Card*
Note that if the card already contains clone data, the display will show
Unit Cloning
Clone Unit from Card*
Use encoder 3 to change to “Make a Clone Card” and press ENTER. Make sure
the ‘Write Protect’ switch on the back right hand corner (as seen from the fitted
position) is set to ‘Off’. SIDD will warn you if the card is protected.
Pressing ENTER will copy the clone data to the card. The unit will then exit to the
default screen.
NOTE: It is crucial that the ‘Write Protect’ switch on the
card is set back to the ‘On’ position before the card is
removed from the unit. Data corruption and loss of all the
information on the card may result if this is not done!
Recalling Clone Data:
Remember that all the settings in the unit will be overwritten when the
clone data is copied!
Selecting the system sub-menu and then
Unit Cloning
will prompt for the insertion of a PCMCIA card. After inserting a card, press ENTER.
The display will show
Unit Cloning
Clone Unit from Card*
Press ENTER to accept, and then again to confirm. The settings from the card will be
copied and the unit will reboot.
DP324 Operators Manual
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Ext. Interface Sub-Menu
Interface Operation
SIDD has as standard three external interface systems MIDI, RS232 and RS485. This
allows complete control via computer (cable or radio) and MIDI ‘Program Change’
command. Setting up the interface depends on whether the unit is in a single unit
system or a multiple unit system.
Single Unit System
Select
Ext. Interface Menu
and press ENTER.
A series of options will now be offered – select as shown below.
Interface Setup
External Mode:Master*
Press ENTER. Now, choose the interface to use (RS232, RS485 or MIDI)
Interface Setup
Master Source: RS232*
Press ENTER. If RS232 or RS485 was chosen, set the baud rate to match your
computers COM port setting
Interface Setup
RS232+RS485 Baud:38400*
Press ENTER. Now, choose the ID number that the unit is to use (analogous to a
MIDI channel, only there are 32 ID numbers available). It is good practice to choose
ID #1 for a single unit system.
Interface Setup
Remote ID Number = 1 *
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DP324 Operators Manual
Multiple Unit System
For multiple unit systems one unit is set as a master, this is the unit connected to the
computer. This unit should be set up as for a single unit system. The remaining units
should be set as slaves and connected via RS485 XLR connectors in a chain to the
master unit.
Set up the slave units as follows.
Select
Ext. Interface Menu
and press ENTER.
A series of options will now be offered – select as shown below.
Interface Setup
External Mode:Slave*
Press ENTER. If RS232 or RS485 was chosen, set the baud rate to match you’re the
baud rate set on the master unit.
Interface Setup
RS232+RS485 Baud:38400*
Press ENTER. Now, choose the ID number that the unit is to use (analogous to a
MIDI channel, only there are 32 ID numbers available). Normally, the master unit is
assigned to ID #1. It makes sense to assign the next unit physically connected to the
master as ID #2, and so on. This makes it easier to troubleshoot, should any units
not respond.
Interface Setup
Remote ID Number = 2 *
For information about how to connect the units together in
various situations, see the section entitled “Typical Interface
Setups” on page 63.
DP324 Operators Manual
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AES/EBU Sub-Menu
SIDD may be factory fitted with an AES/EBU digital interface that provides digital
audio data connections for inputs, the main outputs and the auxiliary outputs.
The AES/EBU digital signal is a stereo data stream, and so only one input XLR and
two output XLR’s are used for the digital interface.
Digital Connections
Connection of AES/EBU signals is via the existing rear panel XLR connectors.
The connections are as follows:
Input A:
Input B:
Switchable between digital (stereo) input and analogue input A
Analogue input B at all times
Main Out 1:
Switchable between digital output (for main outputs 1 & 2) and main
analogue output 1
Analogue main output 2 only
Main Out 2:
Aux Out 1:
Aux Out 2:
Switchable between digital output (for aux outputs 1 & 2) and auxiliary
analogue output 1
Analogue auxiliary output 2 only
Routing Options
Selecting the AES/EBU sub-menu and then
Routing Options
allows selection of the input source – either analogue or digital, and similarly the
output source, again either analogue or digital.
AES Diagnostics
Selecting the AES/EBU sub-menu and then
AES Diagnostics
reports validity flag, clock speed and errors present in the incoming AES digital signal.
The AES options are only accessible when the interface has been fitted.
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DP324 Operators Manual
Typical Interface Set-ups
RS232 Connection (Single Unit)
A typical interface set-up might involve running an RS232 link from laptop or a
desktop computer to one SIDD set up as a master unit. The diagram below shows
this method of connection, the required menu options are also given. Note that the
RS232 cable must be a 1-1 connection type, NOT a null modem cable (which has
connections crossed internally).
RS232 Connection (Multiple Units)
If control over multiple units is required, typically the slaves will be set up to run from
the RS485 ports on the master DP324. Note the incremental ‘Remote ID Num’
option in the unit’s menu options.
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RS485 Connection
To use RS485 communication directly from a computer, a master DP324 must be
configured to receive RS485. You must have a suitable RS485 port on your computer,
or a converter connected to the serial port in use. This configuration is shown below,
along with the required menu options.
Midi Connection
To use MIDI communications, the DP324 must be configured to receive as a master
via its MIDI port. You must have a MIDI card or interface connected to your
computer. The setup is shown below.
Note that two way communication is NOT possible via the MIDI
interface – only download to the unit is possible, and no settings are
returned to the connected computer.
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Look Ahead Delay – Pre-emptive Action
One of the most significant advantages of digital signal processing over analogue is the
ability to delay the audio signal precisely and without extensive complex hardware.
The entire domain of digital signal processing is based around the combination of
delaying, multiplying, and accumulating numbers (representing samples of audio) to
implement all the filters and dynamics processing we have come to expect today.
In the case of dynamics processing, being able to delay a signal allows the processor
module to delay the main signal in relation to the sidechain (the signal being
monitored relative to the threshold), so that it can compensate for peaks prior to the
arrival of the main signal.
Consider the situation of a monitor engineer listening to a band perform1. Having no
access to dynamics processors, he has had to resort to manually ‘riding the faders’ in
an attempt to keep control of the levels. Should the level of one of the channels on
his desk reach an unacceptably high level, he will turn it down appropriately.
There is a hidden
sidechain in operation
even in this case. The
main signal path is fed
through the monitor
desk and the gain
controlled by adjusting
the fader. The sidechain
is formed by the
feedback path between
the engineer’s ears
checking the level and his
brain instructing his hand to turn the fader down if the volume goes over the
threshold he has chosen.
In this case, the delay between the signal actually going over the threshold, the
engineer registering the situation, and then turning the signal down will be in the
order of several hundred milliseconds at best. This will only be true if he is not
distracted – in reality it may be several seconds before any gain reduction is imposed
on the signal to bring it under control.
For an analogue dynamics processor, the situation is much better. Controlling the
gain electronically, and not relying on a human sidechain feedback mechanism, it can
react much more quickly.
1
XTA would like to point out that whilst SIDD might sound male, not all engineers are necessarily male. Some
might well be female, or at least have long hair.
DP324 Operators Manual
Page 65
The red waveform
represents the input to
the dynamics module,
with the dotted line
showing the threshold
for gain control to occur.
There are several peaks
towards the start of this
signal that are above the
threshold, and so the
dynamics processing
should react to these as
appropriate. (In this case
reduce the gain).
The blue waveform
show the output of the
dynamics module. The
circled peak
demonstrates that the
processor has missed the
first peak above the threshold (as it is very fast and short), but has ‘caught up’ shortly
afterwards, keeping all other peaks under control. As it is unable to predict what is
coming, this will always be a failing with analogue dynamics processing.
SIDD’s ability to predelay the sidechain allows it to predict what will be appearing in
the main signal path and react before the signal arrives, thus preventing the overshoot
seen above.
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DP324 Operators Manual
SIDD’s predelayed
sidechain is shown in
green, with the main
signal in red.
As the main signal arrives
slightly after the
sidechain, the output
from SIDD does not
suffer from the
overshoot problem.
Remember that this delay is only in the order of 10 to 60uS,and is a predelay – the
sidechain is moved back in time in relation to the main signal. Inserting a delay into
the main signal path of an analogue dynamics processor will achieve similar results,
but with the penalty of delaying the main signal by the amount of look ahead delay
introduced.
SIDD does not have to use this look ahead delay – in many cases it is preferable to
allow the overshoot. For example, compressing percussive instruments, where the
overshoot retains a degree of the original high frequency energy, stopping the sound
from becoming lifeless and dull.
Times when it is useful include:
• Preventing the limiter from ever overshooting when mastering for digital
media
• Opening the noise gate in advance to prevent clicks
• Ensuring maximum level into a desk using the compressor to level signals
without clipping the input to the channel
DP324 Operators Manual
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Operating Notes
Operating Level
With any audio signal processing equipment it is necessary to ensure adequate signal
level is used through the device, to avoid sacrificing noise performance. It is suggested
that the operating level chosen should give adequate level to just light the +12dB
LED on the headroom meter with maximum program level being used. Since the
meter is deliberately set to show clipping 3dB early, this still provides 9dB of
headroom before clipping occurs. With equalisation in use it may be necessary to
further reduce the input level, as gain within the unit may cause digital clipping,
indicated by the top red LED's lighting independently of the rest of the meter.
It should be noted that the figure quoted for the maximum input level options is the
clipping point for that option (not a safe operating level). Always ensure that this
clipping point is no lower than that for the following equipment in the signal chain,
and allow extra margin if equalisation sections are boosted.
Grounding
The Screen (shield) pins on all audio connectors are normally connected directly to
the ground pin of the IEC mains inlet. The chassis is also directly connected to this
pin. Never operate this unit without the mains safety ground connected. Signal
ground (0V) is in turn connected to the chassis ground.
To avoid ground loops, cable shields should be connected to ground at one end only.
The normal convention is that the shield is only connected at the output XLR.
Provision is also made for separately isolating each input and output shield pin
permanently within the DP324 by breaking the appropriate PCB track, where
marked with a box and an arrow next to each XLR connector using a small drill bit or
cutter. See the following diagram for details.
XLR pin 1 Isolation points (arrowed) and 10dB pads (circled)
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DP324 Operators Manual
Time Alignment
A feature of SIDD is the provision of an independently adjustable delay section for
each output. Delay time is adjustable in 21µS steps (7mm).
Please see page 13 for details of how to adjust the delay times.
To convert from units of time (i.e. milliseconds) to units of distance use the following
formula:
1 millisecond = 343mm (1.126ft) @ 20°C (68°F)
To calculate time delay for a known distance, use:
Time delay =
Distance in meters
20.06 x √273 +°C
where °C is the temperature in °C.
To simplify this equation at 20°C.
Delay time in millisecs = (Distance in meters x 2.192) or (Distance in feet x 0.955)
Note: Centigrade = (Fahrenheit –32) x 0.5555.
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Specifications
Inputs: 2 electronically balanced‹
Impedance: > 10k ohms.
CMRR : >65dB 50Hz - 10kHz.
Outputs: 4 electronically balanced‹
Source Imp: < 60ohms
Min. Load: 600ohm
Max. Level: +20dBm into 600 ohm
Frequency Resp.:+½dB 20Hz-20kHz
Dyn Range:>110dB 20Hz-20k unwtd
Distortion:< .02%@1kHz,+18dBm
Maximum Delay: 300 mS
Min Step Size: 21µS
Input Gain: +15dB in 0.1dB steps
Output Gain: -60dB - +15dB in 0.1dB
steps, and ‘Off’
Parametric Equalisation
6 per Channel
Filter Gain: +15dB to -30dB in 0.1dB
steps.
Freq. Range: 20Hz - 20kHz, 1/36
octave steps. (368 positions)
Filter Q / BW: 0.4 to 128 / 2.5 to 0.008
(Sections switched to shelving
response)
Low frequency: 20Hz - 1kHz
High frequency: 1kHz - 20kHz
Shelf gains: ±15dB in 0.1dB steps.
High and Lowpass Filters
Filters: 1 of each per output.
Freq. Range HPF: 10Hz - 16kHz
1/36 octave steps.
Freq. Range LPF: 35Hz - 22kHz
1/36 octave steps.
Responses:
Bessel/Butterworth 12db/Octave
Dynamics Processing
Dynamic EQ module x 2
Gate/Expander x 2
Compressor x 2
Limiter x 2
Additional Processing
Harmonics Generator
A.D.T.Module
Display:2x24 character backlit LCD
Input meter: 2 x 7 point, -18dB to
+18dB.
Output meter: 2 x 7 point, -18dB to
+18dB.
Gain reduction and Threshold
metering for each module.
Connectors
Inputs: 3 pin female XLR
Outputs: 3 pin male XLR.
MIDI In: 5 pin DIN
External: 9 pin DEE connector (RS232)
RS485:3 pin male XLR (out) 3 pin male
XLR (in)
Power: 3 pin IEC
Power: 60 to 250V ±15% @ 50/60Hz.
Consumption: < 20 watts.
Weight : 3.5kg. Net (4.8kg. Shipping)
Size: 1.75"(1U) x 19" x 11.8"
(44 x 482 x 300mm) excluding
connectors.
Options
‹ = Transformers available.
Optional Interfaces: AES/EBU Digital Input/Output
Due to continuing product improvement the above specifications are subject to change.
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DP324 Operators Manual
Warranty
This product is warranted against defects in components and workmanship only, for a
period of one year from the date of shipment to the end user. During the warranty
period, XTA will, at it's discretion, either repair or replace products which prove to
be defective, provided that the product is returned, shipping prepaid, to an
authorised XTA service facility.
Defects caused by unauthorised modifications, misuse, negligence, act of God or
accident, or any use of this product that is not in accordance with the instructions
provided by XTA, are not covered by this warranty.
This warranty is exclusive and no other warranty is expressed or implied. XTA is not
liable for consequential damages.
Options and Accessories
Part Number
ITX-100
OTX-100
AES-226
OPT-PC1
OPT-103A
OPT-103B
OPT-103C
Part Description
DP324 Transformer balanced inputs (factory fitted only)
DP324 Transformer balanced outputs (factory fitted only)
AES/EBU Digital inputs/outputs (factory fitted only)
‘Type I’ 256k SRAM PCMCIA card
RS232 to RS485 converter (from PC to DP324)
9 pin ‘D’ type to XLR male adaptor cable
9 pin ‘D’ type to 9 pin ‘D’ type cable. (1m)
DP324 Operators Manual
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Appendices
Appendix 1: Limiter threshold in dB to Vrms lookup table.
dB
Vrms
dB
Vrms
+22
9.75
+5
1.38
+21
8.69
+4
1.23
+20
7.75
+3
1.09
+19
6.90
+2
0.98
+18
6.15
+1
0.87
+17
5.48
0
0.77
+16
4.89
-1
0.69
+15
4.36
-2
0.62
+14
3.88
-3
0.55
+13
3.46
-4
0.49
+12
3.08
-5
0.44
+11
2.75
-6
0.39
+10
2.45
-7
0.35
+9
2.18
-8
0.31
+8
1.95
-9
0.27
+7
1.73
-10
0.24
+6
1.55
Calculation:
Vrms = 0.7746 x 10 ^ (dBu + 20)
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Appendix 2: Equalisation Curves
Parametric Filter Gain Curves
Parametric Filter ‘Q’ Curves
Parametric Filter High and Low Shelving Responses
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Page 73
Parametric Filter High ‘Q’ – Notch Filter Response
High Pass Filter Response Curves
Low Pass Filter Response Curves
Please note that SIDD does not currently support 24dB/Octave filters.
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DP324 Operators Manual
Appendix 3: Frequently Asked Questions
How do I update SIDD’s software from the net?
The XTA website http:wvw.xta.co.uk has the latest release of SIDD software posted
on it along with the latest release of the computer control software. Download the
DP324 software, as explained on the software page to a known folder on your ‘C’
drive. Locate the downloaded files on your computer and view the ‘Read me.txt’ file
which will take you through, step by step, how to upgrade the DP226.
You will need a 9-pin D to 9-pin D, male to female serial lead wired pin 1 to pin1.
XTA can supply this cable for you – part number OPT-103C.
What is the best way to connect SIDD to a computer?
The best way is via the ‘External’ RS232 port. This will require a 9-pin D to 9-pin D
lead, as would be used for updating the unit with new software. If it is required to
connect a chain of units to the computer for remote control of an entire system, use
the RS485 XLR sockets to chain the slave units together and to connect them to the
master. This configuration, and several others are explained in the section “Typical
Interface Setups” on page 63.
What kind of PCMCIA card do I need for use with SIDD?
For all applications, whether cloning units, storing sets of memories, storing presets,
or updating software, the unit accepts ‘Type I’ 256K SRAM cards. Note that any card
will only accept one type of data – it is not possible to mix input memory sets, clone
data or any other combination of the data types above on the same card. XTA can
supply this card for you – part number OPT-PC1.
How do I copy settings from one SIDD to another?
This may be accomplished using a function built into the unit known as ‘Unit Cloning’.
See the section entitled “Unit Cloning” on page 58.
Can ordinary microphone cables be used for RS485 connections?
Yes. RS485 is a very robust electrical communication specification, operating point to
point over distances up to 1km. As the system only requires a balanced pair of
interconnects with a screen, normal male to female XLR leads are fine. In fact, as
long as individual pairs are screened, a feed in a multicore may be used.
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Can SIDD be controlled via Audiocore?
No. SIDD has been designed in conjunction with its own proprietary software
package, which is designed to permit full two way communications at all times. As
Audiocore does not operate in this way (the PC is seen as the master in Audiocore
systems), it cannot be adapted to control SIDD. However, multiple SIDD’s may be
connected to the same network (via RS485 In-Out connections). Audiocore will
ignore the units, and SIDD’s software will ignore any other DP-series units.
Note that the maximum number of connected units must still not exceed 32 in total.
What are the maximum cable lengths for RS232 and MIDI
connections?
The specification for RS232 connections details that the cable run should be no
greater than 25 metres. However, newer drivers normally allow runs of approaching
100 metres, as long as good quality cable is used throughout. Dropping the baud rate
will permit greater distances to be achieved in noisy environments or with less wellshielded cables. The specification for MIDI communications is 15 metres. This is an
absolute maximum – XTA recommend taking 10 metres as a better maximum, unless
a MIDI ‘thru’ can be inserted to regenerate the signal.
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