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Page 2 4 Series Operator’s Manual
4 Series Quick Reference
Editing channels : press channel’s GAIN key. First press accesses
that channel’s gain. To scroll through channel’s parameters, use the
BACK and NEXT keys. Second press accesses last viewed parameter.
Third press will drop back to the default screen.
Accessing menus: press the MENU key. Use the BACK and NEXT
keys to select the sub-menu required, and enter the sub-menu using
the ENTER key. This applies to all levels of menu. ENTER always
confirms selections.
Notes
The crossover (output) settings may be stored independently of the
input settings and graphic EQ, using the Global Memory sub-
menu.
The output meters show level, in dB from the limiter threshold, and
the input meters show level from clipping the A-D converters,
pre-gain and all EQ.
The high and low pass crossover filters are defined independently on
each output channel.
Thanks 7
Introduction 8
Features 8
Front Panel Familiarisation 9
Menus in Detail 23
Memory Structure 24
Specifications 50
Warranty 51
Index 52
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
DO NOT EXPOSE TO RAIN, MOISTURE,
DRIPPING OR SPLASHING
ATTENTION
RISQUE DE CHOC ELECTRIQUE
NE PAS ENLEVER
NE PAS EXPOSER A LA PLUIE NI A L’HUMITE
Objects containing liquids, such as vases, must not be placed on this equipment.
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.
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.
Thank you for choosing an XTA 4 Series 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.
Please think of our environment and don’t bin any materials, including this manual. When the product
has reached the end of its useful life, please dispose of it responsibly through a recycling centre.
Each input has a gain control, variable delay, a 28 band graphic equaliser and a further eight bands of fully parametric
equalisation. The parametric filter bands have a large selection of different filter types available, including shelving, notch,
band-pass, phase and elliptical behaviours.
Each output has a gain control, variable delay, high and low pass crossover filters, nine bands of fully parametric
equalisation, polarity switching and, additionally, a fully featured limiter, and a final clip limiter. The crossover filters offer
slopes of up to 48dB/Octave., with a variety of responses available.
Remote control1 is catered for in the form of RS232 and RS485 ports, and multiple user memories are provided for the
storage and recall of settings. A GPI interface may also be fitted to allow remote memory recalls using simple switch
closure apparatus.
The 4 Series are also equipped with AES/EBU digital inputs and outputs, and include a sample rate converter, capable of
accepting anything from 32kHz up tp 192kHz.
They may be controlled externally by XTA’s proprietary WindowsTM software, along with existing and
future ‘AudioCore’ products.
Features
Superb audio quality – carefully optimised double precision signal processing coupled with 24 bit conversion ensure a
dynamic range in excess of 117dB. The high sampling rate of 96kHz means minimal filtering providing exceptional sonic
purity with a bandwidth in excess of 32kHz.
A flexible input/output multi-mode format caters for any configuration, regardless of scale.
Both routing of inputs to outputs, and ganging (for editing) are completely flexible.
A completely new SHARCTM based DSP platform supplies phenomenal computational power, allowing the unit to provide
not only multiple bands of standard parametric equalisation on every input and output, but an additional full spectrum
graphic equaliser on each of the four inputs. This additional power also permits both program limiters and no overshoot
clip limiters on each output.
Delay of up to 650mS may be independently set for each output, with an exceptionally fine minimum increment of 300nS,
which corresponds to a distance change of 0.1mm!
The comprehensive standard specification also includes up to 255 memories, and remote control via RS232 or RS485
ports, with security lockout.
XTA’s new proprietary Complex Unified Nyquist Truncation algorithm ensures that no matter how much equalisation is
applied to a channel, there will always be sufficient headroom available to cater for it.
1
Note that only the RS232 and RS485 interfaces offer full remote control of this product – the GPI interface may only be
used for memory recall (program change) purposes.
Page 8 4 Series Operator’s Manual
Front Panel Familiarisation
LCD Screen: Shows, by default, the
name of the last recalled memory on the
bottom line of the screen, and the
current routing on the top line. Also
used to show all parameters as they are
edited, and all menu selections.
Rotary Encoders: Three velocity sensitive encoders adjust the relevant parameters
as displayed on the screen.
Memory Card Slot: Will accept type I or type II PCMCIA SRAM cards and, using an
adapter, Compact Flash cards. This allows the unit to be cloned, memory sets saved,
presets loaded, and firmware updates installed.
Status LEDs: The four status LEDs show, from left to right, AES inputs selected
(flashing if not locked); AES outputs selected; Comms activity (only illuminates on
messages addressed to this particular unit); and a general-purpose spare indicator.
RS232: 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.
RS485 In-Out: XLR sockets. Used for transmission of remote control data over long
distance or multiple unit applications. See page 28 for more information.
For more details on interfaces see our Interface Guide, available from the website.
Audio Outputs: 3 pin XLR sockets are provided for each channel. All are fully balanced, pin 2 hot, 3 cold, 1 screen.
Note the legending on the panel to designate which outputs are used for AES streams when the digital outputs are
enabled. Please see page 31 for more information.
Always replace the fuse with the correct type and rating as shown on the rear panel legend.
The following operating information covers setup and control of the 4 Series via the front panel controls only. Please
consult the manual supplied with this software for information regarding full computer control.
Start-up procedure
Switching on the unit will display a brief message detailing the unit type and software version running
== AudioCore DP4XX ==
==Software V 1.00 ==
and all LEDs will briefly illuminate. The unit will then begin its countdown to the wake-up procedure2, during which time
the audio will fade up to the level last set. Metering will begin to operate when the fade-up starts.
Preliminary Set-up
The procedure below should be followed when first installing a 4 Series unit.
unit
Crossover
Design your crossover! To do this, press MENU, and use the BACK or NEXT key to select ‘Crossover
sub-
sub-menu’
menu and then press ENTER. Use the BACK or NEXT key to select ‘DesignDesign a crossover’
crossover
and then press ENTER. Finally, use the BACK or NEXT key to select the desired routing3and follow the set-up
wizard to finalise your design.
Note that when in a menu, ENTER is always used to confirm selections. The current selection is marked with an
asterisk ‘*’.
Use the EDIT keys on each output channel with the BACK and NEXT keys to select the high pass filters, low
pass filters, parametrics etc. Note that when designing a new crossover, the high and low pass filters will be set
to default values.
Use the EDIT keys on each input channel with the BACK and NEXT keys to select the gain, delay and
parametrics available on each input.
Note that if no action is taken in menu mode, the unit will return to normal ‘default’ mode after about twenty
(20) seconds. Repeat the above directions to return to menu mode.
2
The wake-up time countdown may be adjusted in the SYSTEM menu – see page 23 for details.
3
For details about adjusting the routing if one of the standard configurations does not suit, see page 15.
4 Series Operators Manual Page 11
Routing Options and Processing Blocks
Due to the completely new DSP platform, the routing possibilities within the 4 Series have been made completely
flexible, with a matrix available allowing any combination of inputs to be routed to any output. The additional DSP power
has permitted the inclusion of more processing blocks, even considering the extra inputs and outputs, and the doubling of
sample rate.
To reduce set-up time and aid usability, several standard configurations are available as described in a later section.
This section will outline the processing blocks available in relation to the signal path, and explain the various options for
routing, including the “Free Assign” mode, which opens up completely flexible channel routing.
The diagram below shows the processing available on each of the four input channels, before routing to the matrix.
The diagram below shows the processing available on each of the eight output channels, after routing from the matrix.
In addition to the ability to assign any combination of inputs to any output, a number of preset configurations are provided,
for use when designing a crossover from scratch. These have the advantage of suggested settings for the high and low pass
filters to useful basic starting points, to filter the different outputs as appropriate for the chosen configuration. These may,
of course, be freely modified afterwards should they not suit the requirements exactly.
The diagrams on the following pages show the connections made between inputs and outputs, and the suggested values
chosen for the high and low pass filters.
2 x 3 way crossover: Inputs A and B feed three outputs each, with output 7 being fed from input C, and output 8 from
input D. Note the ‘Aux’ outputs are set to full range. Default suggested crossover frequencies are shown by each output.
1 x 8 way crossover: Inputs A is fed to all eight outputs, with initial settings being all full bandwidth. The crossover points
can be adjusted as desired.
If none of the preset configurations are appropriate to the required system setup, it is possible to manually select the
routing of the crossover. This is achieved through the Crossover Menu -> Design A Crossover. Crossover
Pressing ENTER will start the crossover design wizard, with the first option being to choose the routing.
or whatever the current configuration is set to. Press BACK until the display shows
And then press ENTER. The EDIT key will illuminate for output 1, as will any relevant input EDIT keys, showing which
inputs are feeding output 1. The display will also detail the current combination of inputs feeding this output. To change
the routing for any output, press its EDIT key, and then choose the required input channel combination by just pressing
the input EDIT keys as appropriate. The input combinations can also be stepped through in turn by pressing NEXT, or
BACK.
To complete the procedure, press ENTER. The wizard will continue, and if the routing has been changed, all outputs will
be muted on exit.
Input Gain
The range of the control over the input gain is –40dB to +6dB in 0.1dB steps.
Gain
Base Delay
The maximum available delay between any input and output is 650.00mS. For example, if the input delay on channel A is
set to 500mS, the maximum available output delay for any output fed from input A will be 150mS. The readout units can
be changed between time in milliseconds, distance in feet or distance in metres. Please see page 23 for more details.
x 1mS x 10uS
343mm 4mm
Input Graphic EQ
The graphic equaliser has 28 third octave bands from 31Hz to 16kHz, and a gain range of +12dB. The G6 on the second
line of the screen denotes the ‘Q’ behaviour of the graphic – this setting behaves like a GQ600 with variable ‘Q’ that is
‘gentler’ at low cut/boost values and sharpens at high cut/boost values. The alternate setting, Sp,
Sp is a constant ‘Q’
behaviour where no change in bandwidth occurs with differing cut/boost. Pressing BYPASS will bypass the entire
Graphic EQ on this channel. For details of how to select the behaviour, please see page 23.
Frequency Gain
Input Parametric EQ
There are eight bands of parameter equalisation available on every input. The behaviour of each individual band can be
changed to a variety of different filter shapes, including high and low shelves, notch, and bandpass. Changing the filter type
is achieved by pressing ENTER during editing any particular band. For more details about the various types of filter
available, please see page 42.
InA Input A PEQ:1<>
1k00Hz Q=3.0 0.0dB
Output Gain
The range of the control over the input gain is –40dB to +15dB in 0.1dB steps.
Gain
Output Polarity
The polarity (or phase) of each output may be switched individually as below.
- or +
Output Delay
The maximum available delay between any input and output is 650.00mS. For example, if the input delay on channel A is
set to 500mS, the maximum available output delay for any output fed from input A will be 150mS. The readout units can
be changed between time in milliseconds, distance in feet or distance in metres. Please see page 23 for more details.
Frequency Slope
Output Low Pass Filter
The low pass crossover filter on each output has a frequency range of 35.1Hz up to >32kHz in 1/36th Octave steps. If you
try to set the low pass filter to a lower frequency than the high pass (which would be pointless and result in no output), the
message High/Low Freq. Overlap! will be displayed. Note that to access the 48dB/Octave filters, parametric
bands 8 & 9 need to be bypassed, or set to 0dB. If they are not, the message Bypass PEQ’s 8 & 9 To
Access 48dB Slopes will be displayed.
Frequency Slope
Output Parametric EQ
There are nine bands of parametric equalisation available on every output4. The behaviour of each individual band can be
changed to a variety of different filter shapes, including high and low shelves, notch, and bandpass. Changing the filter type
is achieved by pressing BYPASS to bypass the filter and then pressing ENTER during editing any particular band. For
more details about the various types of filter available, please see page 42.
4
Note that 2 bands each will be lost when using 48dB slope crossover filters, resulting in a maximum of 5 bands of EQ
when both high and low pass are set to 48dB/Octave.
Page 18 4 Series Operator’s Manual
Output Limiter
The limiter on each output has adjustable attack and threshold, with a release time that is selectable to be a multiplier of
the attack time. For example, as shown below, the attack time is 2mS and release is “x16” so 32mS. The attack and
release times can be automatically linked to the high pass filter frequency, so that they are set to correct values for the
output’s frequency range. If this feature is enabled, the display will show Automatic T/C in place of the attack and
release times. Selection of automatic time constants is through the Design a Crossover wizard, in the
Crossover Sub- Sub-Menu.
Menu
Release Threshold
<-Crossover Ganging
Ganging=1+3+5+7 2+4+6+8
…would be a logical ganging arrangement if the crossover was set up as a 4 x 2 way – linking the control and adjustment of
all “Low” outputs together, and that of all “High” outputs together.
However, if the crossover has not been set up with a preset routing configuration, then it may be required to set up the
ganging to compliment this configuration. This is achieved using the Free Assign mode. This is selected from the
preset ganging choices5, which are:
Ganging=None [all outputs independent]
Ganging=Free Assign [choose ganging]
Ganging=1+2+3+4+5+6+7+8 [1 x 8 way]
Ganging=1+5 2+6 3+7 4+8 [4 x 2 way]
Ganging=1+3+5+7 2+4+6+8 [2 x 4 way]
Selecting Free Assign and then pressing ENTER will begin the process of ganging outputs together using the
following simple rules:
All outputs are ganged to the lowest number – so to gang 3 & 5, 5 must be selected and then ganged to 3.
Outputs cannot share more than one ganging set – so for example output 3 cannot be ganged to 2 and 4 unless
they are ganged together as well. (Effectively 3 and 4 are ganged to 2 in this case)
With these rules in mind, selecting and setting up gangs is quite straightforward.
Press a MUTE key to choose the output to gang – its LED will begin to flash, and an EDIT key will illuminate to show
which output it is currently ganged with. To change this selection, just press another EDIT key, remembering that gangs
work from the highest to lowest number. So, to gang outputs 1 and 5, press MUTE 5 then EDIT 1 – the display will show
<-Crossover Ganging
Gang Output 5 with 1
Ganging is cleared by selecting Ganging=None from the initial choices given above. The Input Ganging
procedure is identical to the crossover ganging, selectable under the Input Sub-
Sub-Menu.
Menu
5 Ganging choices will be dependent on the 4 Series unit in question and how many outputs it has.
Below is an overview of the menu system – a lot of functions have been assigned menu shortcuts – these are accessible directly from the default screen by pressing MENU
followed by the appropriate MUTE or EDIT button as shown. This table only shows the top level of each menu item – some of these will start wizards or access additional
functions, and these will be explained in later sections. Note that currently the menu shortcuts only apply to the DP448.
To jump back to the last menu item accessed directly from the default screen, press MENU three (3) times – first press is into menus, second is a jump to the sub-
menu, third is to the item…
MAIN MENU
GLOBAL INPUT SECTION CROSSOVER INTERFACE SYSTEM SECURITY AES/EBU
MEMORY
Recall a Memory Input Ganging Design a External Interface System Status Unit Locking Output Selection
Crossover
Temperature Alarm
Program Update
Wake-
Wake-up Time
Output Meters
Filter Q/Bandwidth
Delay Time/Dist’nce
Unit Cloning
Preset Up[date
Clip LED Hold Time
Set Date & Time
Note that if no action is taken in menu mode, the unit will return to normal ‘default’ mode after about twenty (20) seconds.. Repeat the above directions to return
to menu mode.
System Status
AES Input
Input Status
-----
-----
Design a Crossover
Input Ganging
Input Reset
Unit Locking
-----
-----
INPUT SECTION
Input Ganging Gang (link) inputs together so their parameters track.
Input Reset Start wizard to reset sections of input parameters, including graphics.
Change Graphic Select between ‘GQ600’ and other graphic behaviours.
Q/BW
CROSSOVER
Design a Crossover Set up a new crossover from scratch. This selection starts a wizard to guide through the
process. Also select this to alter the set-up of the current crossover.
Crossover Ganging Gang (link) outputs together so their parameters track.
INTERFACE
External Interface Starts a wizard to configure the baud rate, ID and port selection of the remote interface.
Wiser 2400 Setup Configures wireless interface (if connected).
GPI Interface Configure the GPI inputs used for closed contact memory recall (hardware option).
SYSTEM
System Status Displays a series of information screens including software version, temperature,
hardware and firmware versions, date and time. Press NEXT to jump through info.
LCD Contrast Adjust the viewing angle of the screen.
LED Brightness Adjust the brightness of all the meters and button LEDs.
Temperature Alarm Set the threshold for the unit to flash a warning temperature message on the screen.
Program Update Select this option to install new operating software – see page 35 for more information.
Wake-
Wake-up Time Adjust the time before the audio fades in on start-up – can also be set to keep mutes on
when powered up.
Output Meters Opt’n Select the monitoring point for the meters – either pre or post mute (so meters can be
set to work even when outputs muted)
Filter Q/Bandwidth Select the readout units for the ‘Q’ setting of parametric filters – ‘Q’ is 1/Bandwidth (in
octaves) – small ‘Q’ values mean wide response variations.
Delay Time/Dist’nce
Time/Dist’nce Select the readout units for all delay values – either time, or distance in feet or metres.
Unit Cloning Copy a unit’s complete setup, including memories and all menu options using a PCMCIA
card. See page 33 for more information on card types.
Preset Update
Update Load a new preset file from a PCMCIA card
Clip LED Hold Time Select the time that the input CLIP LEDs stay illuminated for after an overload has
passed.
Set Date & Time Adjust the real time clock settings.
SECURITY
SECURITY
Unit Locking Protect the unit against unauthorised access with a password - please see page 33 for
more details.
AES/EBU
Output Selection Switch the outputs of the unit to digital. (Inputs are selected via rear panel switch)
AES Status Info. Information screen showing details of the incoming AES streams (sample rate/lock).
INPUT,
INPUT CROSSOVER and GRAPHIC.
There are, therefore, three types of memory available –INPUT GRAPHIC
These, and all combinations of memory types, appear in the GLOBAL MEMORY Sub Menu,
Menu and its operation
warrants a little more explanation.
Selecting to Store or Recall using the Global Memory option offers the possibility of storing various
combinations of the available memory types, and these are selected using the BACK and NEXT keys.
To explain how this all works, please consider the following example.
There are 10 memories stored in the unit with various combinations of input, graphic and crossover memories.
As can be seen, different memory locations contain different combinations of the three memory types available. If it is
required to recall a location that contains Input, Graphic and Crossover settings, this will limit the selection as shown
overleaf…
RS232 Interface
This interface is fitted as standard to all units and is accessed via the 9-pin D-type connector on the rear of the unit. Note
that to connect to a computer’s COM (serial) port correctly, a one-to-one cable must be used, and NOT a ‘null modem’
cable. A ‘null modem’ cable has the ‘transmit’ and ‘receive’ wires swapped over and will not work.
The RS232 connection is suitable for distances of about a maximum of 25 feet between the PC and the unit. If you
experience problems with the connections, consider
• selecting a slower baud rate
• selecting the ‘Use Acknowledge Cmd’ option in AudioCore (see the Remote Menu > RS232 Configuration
window)
• running the unit via the RS485 interface
Note than only one unit at a time may be connected to the computer via this interface. Additional units may be ‘daisy-
chained’ via the RS485 connections from the back of the first one (it acting as a converter for them), but their RS232 ports
are not used.
A typical interface set-up might involve running an RS232 link from laptop or a desktop computer to a 4 Series unit 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).
The unit’s internal software may be updated via the RS232 port ONLY, one unit at a time. We recommend disconnecting
all other devices when updating the software.
The unit’s interface must be set as RS232 Master on ID1 for the PC loader program to recognise it and allow the update to
be sent.
Download the latest version of the loader program and the unit software from www.xta.co.uk, and follow the instructions
included with this zip file. An RSS feed is available on the website to ensure immediate notification of software releases.
If control over multiple units is required, typically the slaves will be set up to run from the RS485 ports on the master unit.
Note the incremental ‘ID NUMBER’ option in the unit’s interface setup.
Shadow ID numbers allow extra units to share the same ID and follow the settings of the ‘main’ ID. This is useful for
larger systems (for example anything above a 4-way stereo system) where it is only necessary to set up one side of the
system, and allow the other unit to track it identically.
Using the shadow IDs in this way also reduces the apparent system complexity within AudioCore. This is due to the
fact that shadow ID’s NEVER send back any settings to AudioCore and because of this will NOT appear in the
list of connected units.
They can be thought of as listening to and acting upon all information addressed to them, but not replying. Up to 128
shadow units may be connected and assigned the same ID as the ‘main’ unit, but remember that the maximum total units
on any one RS485 network is 128.
Shadow ID numbers are accessible when the unit’s interface is configured, and will appear after ID number 128, starting
from 1 again, but designated shadow IDs with an ‘s’ after the number – 1s. Any ID can have multiple corresponding
shadows.
RS485 Interface
XTA has a range of tried and tested interfaces, all of which are
listed in the XTA Interface Guide, available from our website. We
can supply all the interfaces described in this guide directly –
please get in touch.
To use RS485 communication directly from a computer, a master unit 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 unit setup.
Both the converter and the required adapter cables are available from XTA.
The adapter is available in a kit, which includes an RJ-45 adapter, the XLR to 9-pin adapter, and the converter itself. This
complete kit is part number INT-485.
If you need to make up one of the XLR to 9-pin adapters, the pin-out is:
XLR D-type
1 1
2 3
3 8
Both the converters and the required adapter cables are available from XTA.
The adapter is available in a kit, which includes a USB-Serial converter , the XLR to 9-pin adapter, and the K2-ADE
converter itself. This complete kit is part number USB-485. XTA has a range of tried and tested interfaces, including
USB and wireless solutions, all of which are listed in the XTA Interface Guide, available from our website. We can supply
all the interfaces described in this guide directly – please get in touch.
If a DP224/6 receives a MIDI Start or Stop command (used to mute / unmute all outputs) it will relay this message on the
RS485 port to any connected units. The 4 Series units will respond to this message even though it cannot directly receive
MIDI commands, due to not having a MIDI interface ;)
The 4 Series units have a full AES implementation built in as standard. This allows the unit to both receive digital audio
directly, and to transmit digital audio on to other devices. The switching of input and output can be performed
independently, and the inclusion of sample rate converters on the inputs allows the unit to accept sample rates from
32kHz up to 192kHz.
AES Input
Input selection is via a recessed switch on the rear panel of the unit, between input D and output 1. A red LED inside this
aperture illuminates to show that the AES digital inputs
have been selected.
A complimentary LED on the front panel below the
PCMCIA card also illuminates. The switch controls the
rear panel LED directly, whilst the front panel one is via
the processor, allowing it to relay a little more
information.
If it is flashing, this means that AES inputs have been
selected but have not locked. Once a stable AES signal is
being received, it will be permanently illuminated.
AES Output
Pressing ENTER and then using BACK and NEXT chooses either
Analogue or Digital.
Digital Press ENTER again to confirm
selection.
Also under the AES/EBU Sub Menu is the AES Status Information option, which can be used to
check the incoming sample rate(s) and confirm that the data is being received correctly.
This display shows the correct operation of the three AES transmitters V1, V2 and V3. The letter after each is the silicon
version (and is of no importance to the user).
This display shows the status of the two AES receivers, input A on the left, and Input C on the right. The sample rate the
unit has been able to lock to is shown, or UNLOCKED will be displayed in its place. The unit will lock to sample rates
from 32kHz up to and including 192kHz.
The unit’s own processing sample rate is 96kHz, and AES output data is always at 96kHz. Internal sample rate converters
will translate all incoming rates to 96kHz – one converter for each AES input. This allows the two input streams to be at
different rates if necessary.
User Specific
Upon pressing ENTER to select this type of lock, each parameter group is presented in turn. Choose the type of lock (as
above) using the FREQ encoder, and press ENTER to confirm each parameter. After the last parameter, the unit
requests a password. The description of this operation is given at the end of this section.
This option allows the user to specify, for each type of parameter, whether it is to be completely accessible (‘No Lock’),
viewable but not adjustable (‘Control’), or effectively unavailable (‘Display’). The ability to operate mutes, store or recall
memories, or even access the menus may also be locked.
Xover Only
All input parameters are available, but only the gain trim (+ 6dB) is available on the outputs, effectively locking all the
crossover settings. All mutes remain active.
Xover + Trim
All input parameters available, but no output parameters – the crossover sections are completely locked. All mutes remain
active.
Xover + Trim + Mute
As for ‘Xover + Trim’ but additionally, output mutes are locked. Input mutes remain active.
Changes Only
All parameters may be viewed, but none may be adjusted. This applies to both inputs and outputs. All mutes remain
active.
Changes + Views
No parameters are accessible – in effect the EDIT keys do nothing. All mutes remain active.
Changes + Mutes
All parameters may be viewed, but none may be adjusted. This applies to both inputs and outputs. All mutes are also
locked.
EVERYTHING
No parameters are accessible – in effect the EDIT
EDIT and MUTE keys do nothing.
Alternatively, the EDIT keys can be used to enter a code by pressing any combination of the eight buttons. Each EDIT key
represents its channel labelling, so any combination of A, B, C, D, 1, 2, 3, 4, 5,
5 6,
6 7 and 8 can be used as a code, as
shown below. Press ENTER to accept code and then re-enter it to confirm.
To unlock the unit press ENTER and then type the code in. This can be entered by using the FREQ control to select a
character, and the BACK and NEXT keys to move to the next character. Alternatively, the EDIT keys can be used to
enter a code by pressing any combination of the eight buttons. Each EDIT key represents its channel labelling, as described
in the locking section.
Don’t panic! Your unit can still be unlocked. In an attempt to improve the security system on the 4 Series,
Series and prevent
a standard master password from becoming common knowledge, the units now have a random password key generator.
The procedure for unlocking a unit using the password override is explained below:
Switch the unit on with the MENU key held in momentarily. After a few seconds, the unit will ask for a security code.
Use the EDIT keys in the same manner as for entering lock codes (see page 33 for details) and enter 2121.
The Break Code (in the example 12345) should be noted and supplied to XTA. We have software to generate the
corresponding Pass Code which should be typed in, followed by ENTER.
ENTER This will unlock the unit and wipe the previous
password.
Once the Break Code has been noted, do NOT press MENU again during the operation of the unit (except to get back to
this point on power up), or a different code will be generated. The unit may be used as normal, but every press of MENU
will change the Break Code, so the Pass Code XTA supply will not work!
The unit may be switched on and off as necessary – just be sure NOT to press MENU,
MENU or the entire Break Code
procedure will have to be repeated.
Cards bigger than 512Kb in size may be used, but the units will only use the first
512K (i.e. the first 50% 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. Typically, three sets of
presets can be stored on a 512K card. Higher capacity cards will obviously store
more. 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. The unit 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. It’s good practice to note on the card the date of the battery replacement.
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.
The slot is wider than that of previous units as it allows the use of PC card adapters. This permits the use of Compact
Flash cards (with a PCMCIA Adapter) to be used to store information. However, please note
that Compact Flash cards cannot be used for cold start software updates, as they require
formatting and cannot be used as a boot loader, as is required for a cold start update.
PLEASE NOTE THAT THE DATA FORMAT USED ON MEMORY CARDS IS NOT
COMPATIBLE WITH THE WINDOWS STANDARD AND CANNOT BE READ IN A PC CARD
READER.
The preset crossover library may be updated by simply inserting the card containing the new library file into the unit, and
pressing MENU.
MENU The unit will recognise immediately if there is a valid preset file on the card, and display
Preset Update
Press [ENTER]
After the file has been loaded, the unit will re-boot. It is then safe to take out the card.
Insert the card containing the new software into the unit and press MENU.
MENU It will recognise if a newer version is available
on the card, and display a message of the form
Program Update
Press [ENTER]
The unit cloning feature allows the entire “personality” of the unit to be copied onto a PC card for backup purposes, or so
another unit can be instantly reconfigured to operate identically. This will include all user memories, and all user selectable
menu options. Note that OEM presets will not be copied – use the procedure below to copy preset files.
Select Unit Cloning from the SYSTEM Sub- Sub-Menu and then choose to Store or Recall the cloning
information as appropriate. The unit will reboot after the recall procedure.
It is possible to copy the operating software or preset file (or both) onto a PCMCIA card to allow this data to be used in
another unit. This procedure is not part of the standard menu system, and must be initiated on power-on with a special
key sequence.
Be sure to set the Write Protect switch on the card ON before removal, as data corruption can occur as the card is pulled
out of the slot.
This procedure explains how to reboot a unit and load new software
when there has been a problem during a remote download (for
instance the PC has crashed or the unit was switched off duing the
update).
Take the top cover off the destination unit, taking care NOT to touch
the power supply or mains inlet. Move the link maked PC REG to the
location marked SWAP.
Insert the PC card containing the software and switch the unit on.
Make sure the link is put back on PC REG or the card slot will not
function. Replace the cover.
Each input of the 4 Series units has a 28 band graphic equaliser, allowing “traditional” manipulation of the frequency
response in a manner immediately familiar and accessible to all users. The behaviour of the equaliser may be adjusted to
produce an effect similar to either the GQ600, or a “Special” type of response. Both types will be explained in this
section, and what primarily makes them sound as they do. XTA’s AudioCore software has been used in the following
screenshots.
The 4 Series units have two levels of dynamic protection on its outputs – a traditional program limiter, and a newly
introduced “D-Max” limiter.
Program Limiter
High performance digital limiters are provided for each output with control over attack time, release time and threshold
parameters - see page 39 for details. This level of control allows the user to balance the required subjective quality of the
limiter against the driver protection requirements. It does also mean that an incorrectly set limiter may sound awful! In
particular, as with all limiters, using too fast an attack or release time will result in excessive low frequency distortion. In
the Design a Crossover sub-menu there is an option for automatic limiter time constants. Use this option if you
are unsure how to set the time constants manually. XTA recommend the use of the automatic setting.
In this mode the time constants will be automatically set from the High-Pass filter frequency according to the table below.
The time constants are set by the high pass filter frequency for that channel.
The main limitation with traditional dynamics control is the inability of the processing to react truly instantaneously to the
signal. 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 perform. 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.
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.
The blue waveform shows 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.
The “D-Max” limiter which appears in output lists just following the traditional limiter, has only two parameters to adjust:
The release time may also be set to follow the High Pass filter of the output – this is achieved through the Design a
Crossover sub-menu, and will result in the display changing to show
The limiters built into the 4 Series are intended to be used for loudspeaker driver protection, as opposed to amplifier
protection. All modern professional power amplifiers designed for live sound use have their own limiters, which are
tailored to protecting the amplifier from clipping.
The following section describes how to set up the units’ limiters to provide exceptional protection against driver
overheating, and cone over-excursion.
Most speaker systems are given a power rating in Watts RMS. This is the maximum continuous power that the system will
handle and often appears very conservative. In reality, as music program is far from continuous in nature, the peak power
of the system is much higher – up to ten times the continuous figure. Any limiter, which is to protect the driver from
damage, must be able to fulfil the following tasks.
• Have an attack time which is calculated to allow transients through but keep the RMS level below the speaker
manufacturers specification;
• Have a release time which is sufficiently long to avoid the limiter itself modulating the program;
• Be intelligent enough to adjust the envelope of the limiter according to the frequency content of the program
material.
The program limiters are capable of performing all these tasks. The only parameter that the user must set manually is the
threshold, and it is crucial that this is done correctly. Consider the table below.
Using this table it is a straightforward procedure to work out the required setting of the limiter thresholds for the system.
First, check the RMS power rating of the speaker system, and its impedance.
Look up this value in the table above, using the closest value below the rated power of the speaker system. Note
the corresponding ‘dB’ value.
Check the gain of your amplifier, which needs to be in ‘dB’.
Subtract this gain figure from the dB value obtained from the table to find the required absolute setting for the
limiter thresholds.
Note that, for safety, always set the limiter threshold 1 or 2 dB below the maximum allowable worked out using the above
method.
It should also be noted that the turnover frequency displayed on the screen is the -3dB point for all types except Linkwitz-
Riley where the -6dB point is shown. If the -6dB point is to be used for the Bessel or Butterworth filter, take the required
crossover frequency, multiply this by the appropriate factor from the following table and then select the closest available
frequency on the display.
Please note that unlike conventional analogue crossovers, crossover points and slopes are set with absolute accuracy since
component tolerance problems do not occur.
Please see page 18 for details of how to adjust the high and low pass crossover filter settings.
Time Alignment
A further advantage of the 4 Series over conventional products is the provision of an independently adjustable delay
section for each output. This allows the true arrival time from multiple drivers to precisely aligned rather than relying on
the compromise 'phase adjust' approach. Delay time is adjustable in 0.3µS steps (0.1mm).
Please see page 17 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)
Standard Parametric EQ
Various levels of cut and boost are shown to the left, along
with various ‘Q’ settings (gain boosts only are show below).
Notch Filter
Phase Filter
This graph shows the phase shift relative to the input (ignoring
processing delays), in 10° steps – the filter will actually provide
higher resolution than this, operating in 2° steps.The filter is
centred at 1kHz in this example.
The low and high pass variable ‘Q’ filters have adjustable
frequency and ‘Q’ (or Bandwidth) controls. The ‘Q’ control
adjust the damping of the filter, so that low ‘Q’ settings show
less overshoot at the turnover frequency, but also slower roll-
off.
The elliptical filter has adjustable frequency only. This sets the
3dB point of the filter which features a steep roll-off (of approx
36dB/Octave down to one Octave above (or below in the case
of a HPF) the turnover frequency.
To produce a crossover filter of this shape it is simply a case of setting the low (or high) pass filter for that output to the
desired crossover frequency, and selecting a 12dB Butterworth response:
Then select a parametric section on the same output, and modify its behaviour (using the ENTER key) until the
corresponding HPF Elliptical filter is selected. Set the turnover frequency of this filter to be the same as that of the
crossover filter. Make sure you chose a high pass elliptical to work with a high pass crossover, and low pass elliptical to
work with a low pass crossover.
XTA has a range of tried and tested interfaces, including USB and wireless solutions, all of which are listed in the XTA
Interface Guide, available from our website. We can supply all the interfaces described in this guide directly – please get in
touch.
A G
B H
Features · 8 N
Flat Topped EQ · 45
Free Assign · 15 Notch · 46
Front Panel · 9 NTH Response · 49
Options · 51 Security · 33
Output Delay · 17 Security Menu · 23
Output Gain · 17 Shadow IDs · 28
Shelving EQ · 45
Shipping · 7
P Sidechain
Delay · 40
Parametric EQ · 16, 18 Software Updates · 35
Password Override · 34 Special · 38
Passwords · 33 Specifications · 50
PCMCIA Card · 35 Standard Parametric · 44
Phase · 47 Start-up · 11
Polarity · 17, 47 System Menu · 23
Preset Updates · 35
Program Limiter · 19
U
Q Unit Cloning · 36
Unlocking · 34
Quick Setup · 11 Unpacking · 7
Updating Software · 27
Upgrading · 27
R
USB Interface · 26
Rear Panel · 10
Release Times · 39 V
Resonant Filter · 48
Routing · 15 Vari-Q · 48
Basic · 12
Free Assign · 15
Presets · 12 W
RS232 Interface · 26
RS485 Interface · 29 Waranty · 51
3 x 2 way
1 x 6 way
2 x 2 Way
1 x 4 way
2 x 2 Way
1 x 4 way