XTA D2 User manual

Page 2D2 Operators Manual
D2 Quick Reference
THINGS YOU NEED TO KNOW…
üBOLD MEANS HOLD!
Any functions that would produce possible
unexpected level changes at the outputs are
protected by a ‘press and hold’ action and
printed in BOLD on the panel. These
functions are:
Changing MODE between ‘cut below’ and
‘cut above’;
Switching middle band into FULL RANGE
mode;
Enabling the sidechain LISTEN function on
any band.
üThe meters show level, in dB, from the
clipping point of the unit –when the
METER switch is set to ‘IN’ the meters
show level, in dB, from clipping the
input converter. Set to ‘OUT’ they
show headroom available at the output
–the DAC.
üWhen in Shelf mode, the outer bands
only become full range when the Freq
is set to 20k and 20Hz respectively.
üMake-up gain is automatically bypassed
when the Master switch is off.
üOnly one Listen can be active at any
time –selecting another band cancels
the last one.
üThe Listen LED always flashes when
any Listen switch is enabled. Listen is
not automatically turned off if the unit
is switched off and on.
üWhen the unit is bypassed, all its
metering and status LEDs will dim. All
metering will continue to function.

D2 Operators Manual Page 3
Contents
D2 Quick Reference 2
Important Safety Information 4
Thanks 5
Unpacking the D2 5
Introduction 6
Features 6
Front Panel Familiarisation 7
Rear Panel Connections 9
Operating the D2 10
Switching the unit on and start-up procedure 10
Press-and-hold Keys 10
Minimum and maximum control positions 10
What is Dynamic EQ? 11
Setting the Attack and Release times 13
Operating Notes 14
Operating Level 14
Grounding 14
Specifications 15
Warranty 16
Options and Accessories 16

Page 4D2 Operators Manual
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): EN55013-1 (1996)
RF Immunity (EU): EN55103-2 (1996) RF Immunity, ESD, Burst Transient,
Surge, Dips &Dwells
Electrical Safety (EU): 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.

D2 Operators Manual Page 5
Thanks
Thank you for choosing the XTA D2 Stereo Dynamic EQ 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 the D2
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.

Page 6D2 Operators Manual
Introduction
The D2 is a powerful DSP based audio dynamics processor, ideally suited for live
sound applications, where it combines the accessibility and immediacy of a pure
analogue design with the quality and accuracy of a digital design in a compact 1U unit.
To achieve this, the D2 has an analogue control surface, following the ‘one control –
one function’ philosophy and a pure digital signal path, with 24-bit conversion, 40-bit
internal processing and a professional 48kHz sampling rate.
The D2 is also available with optional AES/EBU digital inputs and outputs.
Features
♦Three bands of full range dynamic equalisation on each channel.
♦Independent control of envelope and frequency for each equaliser band.
♦‘Outer’ bands can be set to high and low shelving responses respectively, with
the option of working in full-range if required.
♦Separate ‘Listen’ facility for each band to easily guage its contribution to the
overall channel’s sound.
♦Each band is individually bypassable for complete control, with an overall
channel master.
♦Additional full-range compressor is included.
♦AES/EBU Digital input and output interfaces are available as an option.
♦Input and output balancing transformers are also available as an option.

D2 Operators Manual Page 7
Front Panel Familiarisation
Level Meter: Dependant on the setting of
the ‘METER’ switch, this will display the
instantaneous available headroom, at either
the input to the channel (analogue to digital
converter) or the output from the channel,
post compressor (digital to analogue
converter).
Master Key: Switches the entire channel on/off –LED illuminated when processing
is active. All metering and status LEDs for dim when the unit is bypassed.
Make-up Gain Control: Compensate for gain reduction by adding up to +15dB of
additional gain.
Meter Key: Select what the level meter shows –either input headroom or output
headroom. Still active even when the channel is bypassed.
Full Range Compressor Section:
Threshold Control:
Gain Reduction Meter: The red LEDs indicate
progressively more gain reduction (compression) up to
15dB.
Response Key (Fast/Med/Slow): Select the
attack/release times –fast typically for transient control,
and medium/slow for overall level control. Fast is selected when both LEDs are OFF.
Ratio Key: Set the degree of compression to take place, once the signal exceeds the
threshold, cycling through LOW (both LED’s OFF), MEDIUM and HIGH.
Active Key: Bypass just the full range compressor stage.
Dynamic EQ Bands:
Threshold Control: Adjust the onset of dynamic
control in each particular band, from –30dBu to
+22dBu
MODE Key: Select whether gain reduction is to
occur either above the threshold, or below. Hold
key to change modes.

Page 8D2 Operators Manual
Band Frequency Control: Select the centre (or corner in the case
of shelving response) frequency of the band to be controlled.
’Q’ Control: Select how wide the band of frequencies to be
controlled is, from 2 Octaves (bandwidth = 0.5 –wide) to 0.125
Octaves (bandwidth = 8 –narrow) .
Gain Reduction Meter: The red LEDs indicate progressively more
gain reduction up to 15dB.
LISTEN Key: Switches the output of the sidechain filter into the
main signal path, so that the required range of frequencies may be
more easily selected. LED flashes as a reminder that this is selected.
Shelf Key: Switch between a bandpass filter (with variable
bandwidth) and a shelving response.
Full Range LED: To enable the band to work as a full range compressor/expander,
press the SHELF, and then turn the frequency control fully clockwise/anti-clockwise
(for bands 1 & 3 respectively).

D2 Operators Manual Page 9
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.
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.

Page 10 D2 Operators Manual
Operating the D2
Operation of the D2 is very straightforward, but there are a few points worth noting
which, once understood, will make using the unit even easier.
Switching the unit on and start-up procedure
After plugging in the power and switching the power on suing the rear panel switch,
confirmation is quickly given that all is well by various status LEDs illuminating almost
immediately after power-up. These will include, as a minimum, METER (In/Out);
MODE (Cut Above/Below); and Band Active LEDs .
The gain reduction will fully illuminate and, after the bypass relays disengage, begin to
‘count down’ accompanied by the output level fading up to normal operating level.
The entire process is complete when the input/output meters and gain reduction
begin to operate normally. This whole start-up procedure only takes a few seconds.
Press-and-hold Keys
The legending on the front panel alerts the user to the fact that several keys require a
‘press and hold’ action to initiate them.
These keys relate to functions that could
accidentally introduce large changes of level
at the outputs, causing undesirable effects
and possible damage. These keys have their
function marked in BOLD (and a different
font) to make it clear that they will only
change state if the key is held in for a time.
The keys in question are…
MODE –switching between ‘cut below’ mode and ‘cut above’ mode (See page nn)
LISTEN –switching output to monitor any band’s sidechain EQ signal (See page nn)
FULL RANGE–switching middle band into full range mode (See page nn)
Minimum and maximum control positions To ensure that the D2 is 100% accurate
all of the time, and that what it says on the
front panel is exactly what the unit is
doing, it has been necessary to introduce
‘end-stops’ on the controls.
The extreme regions on each control
marked with the curved line designate this
entire region as relating to the parameter
value shown. This is to compensate for the mechanical tolerances of the
potentiometers.

D2 Operators Manual Page 11
What is Dynamic EQ?
Dynamic EQ is essentially a compressor or expander that can be set to respond and
act upon only a certain range of frequencies. Its behaviour is dependent on the
operating mode chosen: the operating modes are explained in detail below.
Mode I: “Cut Above”
Having selected the frequency band to work with, the dynamic eq will listen to this
band and act upon it by cutting(compressing) any frequencies present in it that go
above the predetermined threshold. Consider the example below where the
threshold is set to –20dB, and the selected frequency band is centred around 1kHz,
with a ‘Q’ of 1.0.
Signals below the threshold will pass unaltered, but as increasing signal is applied,
those frequencies centred around 1kHz will be cut or compressed. The ratio in the
above example is set at 2:1 so, as with any compressor, the amount of gain reduction
applied depends on how much the signal exceeds the threshold. The red line
represents a signal at 0dB, which is 20dB above the threshold. At 1kHz, therefore,
the signal has been compressed to –10dB or 2:1.
Uses of “Cut Above” mode.
Traditional use of ‘frequency conscious’ compression is to control or ‘tame’ a certain
band of frequencies within the program material. Insertion of EQ into the sidechain
will make the compressor respond to the required band, but it will cause broadband
compression of the signal, so any peaks will cause the entire signal to be compressed.
This produces the familiar problem of dulling the material if it is bass-heavy, or
causing unnecessary dips and changes in ambience when attempting to remove
sibilance.
The difference with dynamic EQ is that only the band selected is compressed. This
means that it becomes possible to compress the low frequency content of material
without affecting the high frequencies at all. The result is increased volume and
perceived level with out sacrificing clarity. Any instance where the desired result is to
control a band of frequencies, such as de-essing, or de-popping, without affecting the
surrounding frequency ranges is an ideal use for this mode.

Page 12 D2 Operators Manual
Try de-essing with the filter centred at 8-9kHz, and a relatively narrow ‘Q’ of about
4, attack 1mS, release 100mS.
Mode II: “Cut Below”
Having selected the frequency band to work with, the dynamic eq will listen to this
band and act upon it by cutting any frequencies present in it that drop below the
predetermined threshold. Consider the example below where the threshold is set to
+10dB, and the selected frequency band is centred around 1kHz, with a ‘Q’ of 1.0.
Signals above the threshold will pass flat, but as the level decreases, those frequencies
centred around 1kHz will be cut or expanded. The amount of gain reduction applied
depends on how much the signal drops the threshold and the ratio set –a 2:1 ratio
would mean that for every drop of 1dB below the threshold, the band centred
around 1kHz would drop by 2dB.
Uses of “Cut Below” mode.
Reducing the level of high frequency noise can be effectively implemented in this
mode. Particularly effective on percussive material, unwanted tape noise and
interference can be usefully removed without affecting the signal at normal levels.
Try the filter set to a high shelf mode at 4kHz, attack 25mS, release 100mS. The
threshold setting is more crucial in this mode than usual, with the trade-off being
effective removal of noise against possible intrusive dulling of the program material.

D2 Operators Manual Page 13
Setting the Attack and Release times
As with all compressors and expanders, using too fast attack and release times on low
frequency program (such as a bass guitar) will cause the gain reduction to respond to
individual cycles of the signal, rather than the overall envelope. This will result in
obvious distortion, which might be described as sounding like clicking superimposed
on the original signal.
The compressor release time has been deliberately restricted to a minimum of 25mS
to prevent excessive distortion on low frequency signals, even with fast attack times
and high ratios. None the less, it is still possible to introduce some distortion if care is
not taken with the settings. The best way to ensure that the signal is not being
excessively distorted is to make good use of the ‘ACTIVE’ button, constantly
comparing the original signal with the compressed version.
The preset1attack and release times used for the dynamic EQ and the full range
compressor are given in the table below.
Attack/Release Fast Response Medium Response
Slow Response
Dynamic EQ Band Frequency dependant Frequency dependant Frequency dependant
Compressor 0mS/50mS 3mS/150mS 15mS/600mS
As a rule of thumb –the higher the frequency control is set for any particular band,
the faster the response should be –typically…
Slow Response -< 150Hz
Medium Response -~150Hz -~3kHz
Fast Response -~3kHz –20kHz
1The dynamic EQ bands attack and release times are linked to the centre frequency of the respective
band and vary accordingly –high frequency settings will utilise faster attack and release times.

Page 14 D2 Operators Manual
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 D2 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)

D2 Operators Manual Page 15
Specifications
Inputs: 2 electronically balancedu
Impedance: > 10k ohms.
CMRR : >65dB 50Hz -10kHz.
Outputs: 2 electronically balancedu
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
Dynamic EQ Bands:
Threshold: -30dBu to +22dBu
Ratio: 1:1 to 16:1
Attack: -60uS to 250mS
Release: 25mS to 4 S
Make-up Gain: 0 to +15dB
Sidechain EQ Section
Type: Selectable high/low shelf or
narrow/wide parametric response.
Centre/corner Freq: 20Hz to 20k
Gain: +6,9 or 15dB and ‘Off’
Sidechain monitor available.
Input/Output meter: 6 point,
-12dBu to +18dBu.
Gain Reduction meter: 4 x 6 point,
1dB to 15dB gain reduction.
Connectors
Inputs: 3 pin female XLR
Outputs: 3 pin male XLR.
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 u= Transformers available.
Optional Interfaces AES/EBU Digital Input/Output
Due to continuing product improvement the above specifications are subject to change.

Page 16 D2 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 Part Description
ITX-100 D2 Transformer balanced inputs (factory fitted only)
OTX-100 D2 Transformer balanced outputs (factory fitted only)
AES-D2 AES/EBU Digital inputs/outputs (factory fitted only)