Cloud CXA215K User manual

Installation and User Guide
CXA21K & CXA215K Manual V1.1
CXA SERIES DIGITAL AMPLIFIERS
MODELS: CXA21K & CXA215K

Technical and Safety Notices
Please read the following important technical, safety and
environmental notices before installing and using your
amplier.
Technical Notices
All reasonable design and engineering steps have been taken to
ensure that these ampliers always perform satisfactorily in their
intended application and environment and will provide appropriate
levels of support to ensure that all reasonable customer needs and
expectations are met. Such support however is contingent on the
following provisions.
1. These ampliers are Class-I products and should be installed with
a mains cable including the required earth connection to comply
with the Safety Class-I.
2. These ampliers should always be installed by competent
and qualied personnel. Amplier damage or failure caused by
installation or operational errors may invalidate support, warranty
or guarantees of performance.
3. These ampliers are not suitable for use in locations where they
may be accessible to minors.
4. These ampliers are intended to be used specically for the
amplication of audio signals and for connection to moving-coil
loudspeaker systems. Use of these ampliers for amplication
of signals outside the audio band (20Hz to 20kHz) or to drive
transducers other than moving-coil loudspeakers may invalidate
support, warranty or guarantees of performance.
5. These ampliers should only be used within professionally
installed and congured audio systems comprising input and
output ancillary equipments that is known to be of an appropriate
level of performance and in good operating condition. Any damage
to, or unsatisfactory performance from, these ampliers caused
by inadequate or failed input or output ancillaries may invalidate
support, warranty or guarantees of performance.
6. These ampliers are intended to be installed and operated indoor
in a controlled environment (pollution degree, PD2) within an
ambient temperature range of 0°C to 40°C. These ampliers are
not intended for use above 2000 meters above sea level. Ampliers
installed or operated in environments outside these limits may
invalidate support, warranty or guarantees of performance.
7. Specic warranty terms are the responsibility of the amplier
re-seller.
Safety and Environmental Notices
Note: The intent of the lightning ash with arrowhead symbol in a
triangle is to alert the user to the presence of uninsulated “dangerous”
voltage within the product’s enclosure that may be of sufcient
magnitude to constitute a risk of electric shock to humans.
Note: The intent of the exclamation point within an equilateral
triangle is to alert the user to the presence of important safety, and
operating and maintenance instructions in this manual.
WARNING! TO PREVENT FIRE OR ELECTRIC SHOCK, DO
NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
Ambient Temperature Note: If this equipment is operated
in a conned or multiple rack installation, the internal
ambient operating temperature may exceed the external
ambient temperature. It is important to ensure in these
circumstances that the published maximum operating
temperature for the equipment is not exceeded.
Reduced Air Flow: Ensure that rack or other
closed installation does not restrict the
cooling airow required for safe and reliable
operation of the equipment.

Technical and Safety Notices
Important Safety Instructions
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Do not submerge the equipment in water or liquids.
7. Do not use any aerosol spray, cleaner, disinfectant or fumigant
on, near or into the equipment.
8. Clean only with a dry cloth.
9. Do not block any ventilation opening. Install in accordance
with the manufacturer’s instructions.
10. Do not install near any heat sources such as radiators, heat
registers, stoves, or other apparatus (including ampliers) that
produce heat.
11. To reduce the risk of electrical shock, the power cord shall be
connected to a mains socket outlet with a protective earthing
connection.
12. Do not defeat the safety 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 wide blade or the third prong are
provided for your safety. If the provided plug does not t into
your outlet, consult an electrician for replacement of the
obsolete outlet.
13. Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles, and the point
where they exit from the apparatus.
14. Do not unplug the unit by pulling on the cord, use the plug.
15. Only use attachments/accessories specied by the
manufacturer.
16. Unplug this apparatus during lightning storms or when unused
for long periods of time.
17. Refer all servicing to qualied service personnel. Servicing is
required when the apparatus has been damaged in any way,
such as power supply cord or plug is damaged, liquid has been
spilled or objects have fallen into the apparatus, the apparatus
has been exposed to rain or moisture, does not operate
normally, or has been dropped.
18. The appliance coupler, or the AC Mains plug, is the AC mains
disconnect device and shall remain readily accessible after
installation.
19. Adhere to all applicable, local codes.
20. Consult a licensed, professional engineer when any doubt or
questions arise regarding a physical equipment installation.
Environmental Statement
This product complies with international directives,
including but not limited to the Restriction of
Hazardous Substances (RoHS) in electrical and
electronic equipment, the Registration, Evaluation,
Authorization and restriction of Chemicals (REACH)
and the disposal of Waste Electrical and Electronic
Equipment (WEEE). Consult your local waste disposal authority for
guidance on how properly to recycle or dispose of this product.

Introduction and Overview
1. Introduction
CXA21K and CXA215K power ampliers have been
designed to provide congurable, consistent and
reliable high performance audio power amplication for
residential, commercial and entertainment applications.
This manual covers the features, installation and functions
of the CXA21K and CXA215K models. Please read the
manual fully before installing and using an amplier. If
you have any questions regarding amplier conguration,
installation or operation please contact the appropriate
customer support portal.
Following this introduction, the manual is divided into sections
covering the following topics:
• 2. Overview
• 3. Carton Contents
• 4. Installation
• 5. Conguration
• 6. Connections
• 7. Operation
• 8. Specications
2. Amplier Overview
CXA21K and CXA215K ampliers are a full rack width, 2U format
power ampliers that can drive both conventional low impedance
(Lo-Z, 4Ωto 16Ω) loudspeakers and high impedance (Hi-Z,
70V/100V) transformer coupled loudspeakers. They provide four
analog inputs, one stereo S/PDIF digital input, and either two or
four outputs (Lo-Z mode), or one or two outputs (Hi-Z or Lo-Z BTL
mode). CXA21K and CXA215K amplier model output channel
counts and power outputs are as follows:
CXA21K
Mode Channels Max Rated Output per Channel
Lo-Z Four 500 Watts
Lo-Z (BTL) Two 1000 Watts
Hi-Z Two 1000 Watts
CXA215K
Mode Channels Max Rated Output per Channel
Lo-Z Four 750 Watts
Lo-Z (BTL) Two 1500 Watts
Hi-Z Two 1500 Watts
Note: In Lo-Z BTL (bridge-tied load) mode, two amplier output
channels are combined to create a single, double power output
channel. BTL mode can be engaged via the amplier Output Mode
conguration setup menu described in Section 5 of this manual.

Introduction and Overview
2.1 Connections and Power Switching
CXA21K and CXA215K signal input and output connections are
accomplished via RCA Phono and Euroblock style connectors. A
GPIO (General Purpose In/Out) Euroblock connector enables some
amplier functions to be controlled externally, and wireless or RJ45
socket Ethernet network connection options are also provided.
Cable connectors and connections are described and illustrated in
Section 6 of this manual
CXA21K and CXA215K ampliers incorporate a front panel
mounted power button. Press the button once to switch the
amplier on or off. Amplier power management behaviour can
be congured via the Control web app Settings Menu described in
Section 5 of this manual.
2.2 Network Features
CXA21K and CXA215K ampliers are TCP/IP network connected
devices that require a wired or wireless network connection to
access their conguration menus. The conguration menus are
accessed via the Control Web App interface and cover Input, Zone,
Output and General Settings functions. The Control web app
conguration menus are described in Section 5 of this manual.
2.3 Firmware
This manual describes the features, functions and user interface of
CXA21K and CXA215K ampliers running Firmware Version 1.5
It is strongly recommended that the rmware version installed
in the amplier in use is checked initially, and regularly
thereafter. If updated rmware is available, the amplier
should be updated as a priority.
The rmware installed in the amplier can be identied and
updated by selecting the Device option in the Control web app
Settings Menu. Firmware versions can be checked, and rmware
downloaded, from the website: https://???
3. Carton Contents
CXA21K and CXA215K ampliers are shipped in a cardboard
carton containing the amplier unit, a mains cable appropriate for
the sales territory, an accessory pack, and a document pack. The full
contents is listed below.
• Amplier unit
• Rack mount ears (tted)
• Mains power cable
• Input connector x 2
• GPIO socket connector
• Output connector x 1 or 2
• Adhesive rubber feet x 4
• Document pack

Installation
Diagram 4A
CXA21K and CXA215K amplier dimensions.
(Shaded area denes ventilation space.)
440 mm
17.3 in
332 mm
13.1 in
4. Installation
4.1 Amplier Location
CXA21K and CXA215K ampliers are shipped with rack
“ears” attached and are primarily intended for standard (19 inch)
equipment rack installation. If not to be installed in an equipment
rack, CXA21K and CXA215K ampliers can be placed free-standing
on a at surface. Adhesive rubber feet are supplied for this purpose.
It is important that any installation provides space for airow
through the ventilation apertures at the front and rear of the
amplier. This is illustrated in Diagram 4A.
88 mm
3.5 in

Conguration
5. Conguration
Before making input, output and GPIO connections, an
initial CXA21K and CXA215K amplier conguration
should be established. It is particularly important that the
amplier output format is congured appropriately for
the speakers that are to be connected.
Conguration requires that CXA21K and CXA215K
ampliers are connected to mains power, switched on
and connected to network services. These connections are
described in the following two sections.
5.1 Mains Power Connection
CXA21K and CXA215K ampliers incorporate a power factor
corrected power supply and can be used with mains input voltage
from 100V AC to 240V AC, 50/60Hz. Use the mains cable supplied
with the amplier and connect it to a mains supply.
Press the front panel power button to switch on the amplier. After
a short delay the front panel Status indicator will illuminate green.
5.2 Network Services
CXA21K and CXA215K ampliers are congured via
the Control Web App interface. Before the Web App
conguration menus can be accessed, CXA21K and
CXA215K ampliers must be connected to the same TCP/
IP network as the computer or mobile device that is to be
used for conguration.
5.2.1 Wired (Ethernet) Network Connection
To connect a CXA21K and CXA215K amplier to a TCP/IP network
using a wired connection (Ethernet) follow the steps below.
1. Use an Ethernet cable to connect the CXA21K and CXA215K
amplier rear panel Network Control socket to a free socket on
a network router or switch, or directly to an Ethernet equipped
laptop or desktop computer.
2. Connect the CXA21K and CXA215K amplier to mains power
using the supplied mains cable. Wait for the front panel Network
indicator to illuminate green to indicate that the amplier has
network connectivity.
3. The CXA21K and CXA215K amplier default LAN IP address
is 192.168.64.100. Congure the laptop or desktop computer for
a xed IP address in the same IP range; eg. 192.168.64.10, with
Subnet mask of 255.255.255.0 (or prex 24) and set the Gateway
to 192.168.64.1.
4. Open a laptop or desktop web browser and enter the address
http://192.168.64.100. The Control Web App interface will open to
enable amplier conguration as required.
Note: CXA21K and CXA215K ampliers can be congured to use
DHCP for network connection if required. However, if a CXA21K and
CXA215K amplier using DHCP is power cycled, it is possible that
the TCP/IP network router will assign it a different IP address, leaving
its conguration page inaccessible via the previous address. If this
occurs, a network scanning app can be used to identify the new IP
address. DHCP and Fixed IP address option settings can be found in
the Settings Tab menu described in Section 5.3.
5.2.2 Wireless (WiFi) Network Connection
To connect a CXA21K and CXA215K amplier to a TCP/IP network
using a wireless connection (WiFi) follow the steps below.
1. With the CXA21K and CXA215K amplier connected to mains
power, wait for the front panel WiFi indicator to illuminate green.
2. Use a mobile, laptop or desktop device to search for available
WiFi networks. Connect to, CXA21K and CXA215K (product serial
number)’ using the password, ‘password’. The amplier serial
number can be found on its rear panel.
3. Open a computer or mobile device web browser and enter the IP
address: 192.168.4.1. The Control Web App interface will open to
enable amplier conguration as required.
4. Select the Web App Settings Tab followed by WiFi > WiFi Mode
> Client to congure the amplier to connect to the required WiFI
network. The WiFi network name and password will be required.
It is strongly recommended that the CXA21K and CXA215K
amplier Access Point WiFi password is changed following initial
wireless connection.

Conguration
5.3.1 Input Tab
The Input Tab provides the following conguration parameters for
each amplier input channel:
• Input name
• Mono/Stereo selection
• Input sensitivity
• High-pass lter
• Gain trim
• Five band equalisation
The Input Tab also enables input signals to be mixed and routed
to specic amplier zones. The mix function enables any amplier
input, including stereo or split mono S/PDIF inputs, to be grouped
with any other input or inputs to create multiple predened mixes.
Note: The number of individual mixes possible is equal to the number
of amplier analogue inputs.
Note: Mix inputs are muted by default with their level adjustment
sliders set to zero.
Mix operations take place following high-pass lter, input
equalisation and mono/stereo selection.
Diagram 5A
Conguration Dashboard display
Diagram 5B
Input Tab display
(two inputs only shown)
Input name - type to edit
Select mono or stereo
Select input sensitivity option
Adjust input gain
Open EQ window
Adjust zone volume
Adjust zone volume
Note: When adjusting input gain, the input level display should remain
green. If it displays red, the input gain should be reduced.
5.3 Conguration Menus
Opening a web browser that is network connected to a CXA21K
and CXA215K amplier initially displays the CXA21K and
CXA215K Control Web App Dashboard illustrated in Diagram
5A. The Dashboard is the ‘home’ page from which all other
conguration options can be accessed.
The Dashboard displays the amplier status, output zones and the
conguration menu tabs. It also enables immediate access to zone
volume control The functions available under each conguration
menu tab are described in the following sections.
Select input type

Conguration
Diagram 5C
Input EQ display
Diagram 5D
Input Mix display
A pink noise or sine wave audio signal generator, appropriate for
audio system testing and set up, can also be enabled, disabled, and
adjusted for gain and frequency via the Input Tab. Diagrams 5B, 5C
and 5D illustrate the Input Tab, Input EQ and Input Mix displays
respectively.
5.3.2 Zone Tab
The Zone Tab enables installation zones to be dened and named,
and provides access to further sub-menus. Zones might be bar or
restaurant areas for example, or different rooms in a home. For
all Zone Tab menus, the installation zone under conguration is
selected by highlighting one of the zone identiers (A, B, C or D) at
the top of the display. Diagram 5E and 5F illustrates the Zone Tab
and Source menu displays.
• The Source menu enables inputs to be assigned to zones
and Input Priority or Input Ducking to be congured. The
Input Priority function enables an alternative input to
replace and mute the input primarily routed to the zone under
conguration when the alternative input exceeds a preset level.
The Input Ducking function enables an alternative input to
replace and attenuate the input primarily routed to the zone under
conguration when the alternative input exceeds a preset level.
Zone name - type to edit
Select zone
Select mix function
Select mono or stereo
Select zone input
Congure zone volume options
Congure zone restrictions
Congure zone compressor
Adjust zone volume
Diagram 5E
Zone Tab display
Select and adjust required EQ stages
Mix name - type to edit
Adjust mix input level

Conguration
Note: Input Priority and Input Ducking parameters can be either set to
default values or their Threshold, Attack, Hold and Release values set
as required. Input Priority can also be set to ignore the volume level
set for the specied zone and take a specic override volume.
• The Volume menu allows minimum and maximum
zone volume limits to be set, and enables external GPIO
volume control to be applied to individual zones. The GPIO
conguration menu can be found under the Settings Tab, and
notes on connecting an external volume control via the GPIO
interface can be found in Section 5.5 of this manual.
Note: If an amplier is controlled via a third-party control system API,
volume level limits set via the Input Tab will not apply.
• The Restrictions menu enables zone inputs or input mixes to
be restricted from routing to particular zones.
Note: Routing restrictions cannot be applied to priority zone inputs.
Note: If an amplier is controlled via a third-party control system API,
input routing restrictions set via the Input Tab will not apply.
• The Compressor option enables default or custom signal
compression to be applied to individual zones.
Note: Compression can be useful to reduce the volume difference
between loud and quiet audio material. The lower the compression
threshold is set, the more the difference between loud and soft
will be reduced. The overall zone volume may need to be increased
when compression is used. The default compression parameters are
appropriate for most installations.
5.3.3 Output Tab
The Output Tab enables amplier outputs to be named, linked to
zones, and provides access to Delay, Equalizer and Speaker Preset
menus. Diagram 5G illustrates the Output Tab display.
For all Output Tab menus, the amplier output under conguration
is selected by highlighting one of the output identiers (1, 2, 3 or 4)
at the top of the display.
Note: The number of individual outputs available for conguration
will depend on the CXA21K and CXA215K amplier model and the
input, zone and output mode conguration.
• The Routing menu enables zones to be assigned to amplier
outputs.
Note: Routing for zones specied as stereo will automatically offer
three output options: left channel, right channel or summed mono.
The summed mono signal can potentially be used to drive a mono
subwoofer.
• The Delay menu enables delay to be applied to individual
amplier outputs.
Output name - type to edit
Select output
Enable and congure output delay if required
Dene output routing
Enable and congure output EQ if required
Congure and manage speaker presets
Diagram 5G
Output Tab display
Diagram 5F
Zone Source menu display
Select zone

Conguration
• The Equalizer menu enables parametric equalization to be
applied to individual amplier outputs. Equalizer settings
congured for one amplier output can be copied and applied
to other outputs.
• The Speaker Preset menu enables a set of speaker parameters
to be adjusted, and preset congurations to be created,
exported, imported or cleared.
Speaker Presets can be simply applied to the selected amplier
output or imported, chosen from a library, exported or
cleared. The preset congurations can include any or all of the
parameters described in Section 5.3.4 and can be locked to
prevent inadvertent modication. Diagrams 5H to 5K illustrate
the application of speaker presets.
Speaker Preset data provided by third parties for use with
specic speakers can be imported and applied to amplier
outputs. To import speaker preset parameters follow the steps
described below and illustrated in the diagrams.
1. Select either the IMPORT PRESET FROM LIBRARY or
SELECT PRESET FROM FILE option from the Speaker
Preset menu. If no import option is visible, select
CLEAR to delete any existing speaker preset data.
Note: The SELECT PRESET FROM LIBRARY option will be unavailable if
no speaker preset libraries have been created. Speaker preset library
creation and management is described in Section 5.3.5.
2. Select the appropriate ‘.zcp’ format speaker preset
data le to import from either a Library or a computer
folder. The preset data will be applied to the selected
amplier output as soon as the le import is complete.
3. If the Speaker Preset data requires modication it can
be customized by selecting the CUSTOMIZE PRESET
option.
Note: If an imported Speaker Preset data le includes locked
parameters, they will be unavailable for modication.
5.3.4 Speaker Preset Menu Parameters
• The Crossover & Gain preset menu enables high or low-pass
crossover lters and gain adjustment to be applied to individual
amplier outputs.
• The Speaker EQ preset menu enables parametric equalization
to be applied to individual amplier outputs.
Select to congure
Select to congure
Select to congure
Select to congure
Select to congure
Select to congure
Select to congure
Select to congure
Diagram 5H
Speaker Preset Parameters
Diagram 5I
Speaker Preset import le selection
Select output

Conguration
Diagram 5J
Speaker Preset applied
Diagram 5K
Speaker Preset parameter adjustment
• The FIR preset menu enables FIR (Finite Impulse Response)
based equalization lter coefcients generated by external
speaker measurement software to be imported and applied to
individual amplier outputs.
Note: FIR coefcient les in either .csv or .txt format can be imported.
• The Driver Alignment preset menu enables delay to be applied
to individual amplier outputs.
• The Polarity preset menu enables the polarity of individual
amplier outputs to be reversed.
• The Limiter preset menu enables signal limiting to be engaged
or bypassed on individual amplier outputs. Clip limiting, Peak
limiting and RMS limiting can be individually or collectively
engaged. The Clip limiting function offers Fast and Normal
response time options. The Peak limiting function can be set to
either Automatic or Manual parameter values. The RMS Limiter
has default parameter values that can be adjusted but has no
automatic option.
Note: It is strongly advised that if an amplier is driving low
impedance loads (<4Ω) the Clip Limiter should be engaged and set to
Fast.
Note: In automatic mode, the peak limiter parameters adjust
automatically in response to Crossover & Gain high-pass lter
settings.
• The Output Mode preset menu enables individual amplier
outputs to be switched off or congured for Lo-Z or Hi-Z
modes. In Hi-Z modes, a high-pass lter can also be congured
and applied to the output. The number of outputs available will
depend on the amplier model, input setup and zone setup. For
example, a two output amplier will have two outputs available
if Lo-Z mode is selected but only one output available if Hi-Z
mode is selected.
Note:: Use of a high-pass lter with Hi-Z mode loudspeakers is useful
to avoid the possibility of distortion caused by low frequency line
transformer saturation. Begin with the default lter setting of 70Hz. If
low frequency distortion is still audible, increase the frequency setting
one step at a time until the distortion is no longer audible.

Conguration
Diagram 5L
Settings Tab menu
Diagram 5M
The External Devices display
External device - tap to congure
5.3.5 Settings Tab
The Settings Tab enables miscellaneous amplier settings to be
congured and installation data to be recorded. The Settings Tab
provides access to further sub-menus. Diagram 5L illustrates the
Settings Tab.
• The System Information menu provides text elds for the
recording of installation data.
• The Device menu records amplier specic information such
as the model number and rmware version. A rmware update
routine and identier button can also be found under the
Device menu.
• The External Devices menu enables control panels to be paired
with an amplier and congured. Each individual amplier
zone to be controlled will require its own control device.
Diagram 5M illustrates the External Devices display.
• The Backup & Restore menu enables amplier conguration
data to be downloaded to an external archive, and enables
previously saved conguration les to be uploaded and adopted
by the currently connected amplier.

• The Speaker Library menu enables management of speaker
preset libraries. Existing libraries of speaker preset les (.zcl)
can be created or imported, and existing libraries edited or fully
deleted. Diagram 5N illustrates the creation and management
of speaker preset libraries.
• The Security menu enables a password to be set in order to
protect against unauthorised access to the amplier Control
Web App. Password protection is particularly important when
an amplier is connected to a wired network as the a WiFi
password is no longer required to gain access to Control Web
App.
Note: It is recommended that a Control Web App password is different
from that required to gain access to the amplier via WiFi.
• The Power Management menu enables various automatic
switch-on options to be engaged. The Power Management
menu also offers timed Standby and Mute functions.
• The Output Routing menu enables specied inputs or zones to
be routed to the amplier S/PDIF outputs. The output level can
also be adjusted.
Any zone or input can be routed to either digital output,
including inputs not actively assigned to a zone. Primary or
priority input status is immaterial. The specied input is always
routed to the specied output to be available for use by
downstream devices.
Note: The digital output function is especially useful when ampliers
are to be daisy chained and a specic input; a central paging mic, for
example, is required to be routed to multiple ampliers..
• The GPIO menu enables conguration of the multi-purpose
GPIO interface pins.
• The LAN menu enables conguration and reset of the wired
network options and parameters.
• The WiFi menu enables conguration and reset of the wireless
network options and parameters.
Conguration
Diagram 5N
Speaker Library Creation and Management
Library name - type to edit
Library version - type to edit
Import preset data (.zcp) to library
Creat new library
Rename library
Delete library

Conguration
Diagram 5O
Signal Flow Schematic
(four output amplier)
Analog 3
Output
Matrix
Zones A - D
Outputs 1 - 4
Analog 2
Input
Sensitivity
Analog 1
Input
Gain
Input
Sensitivity
Input
Gain
Input
Sensitivity
Input
Gain
Analog 4
SPDIF (stereo)
SPDIF Out (any two input or zone signals).
Pink Noise Gain
Delay
Level
Adjustment
Level
Adjustment
Level
Adjustment
Level
Adjustment
Compressor Compressor Compressor Compressor
Delay Delay Delay
EQ EQ EQ EQ
EQ EQ EQ EQ
FIR FIR FIR FIR
Polarity Polarity Polarity Polarity
Limiter
BTL
Amplifier
2 x Low-Z
1 x Hi-Z
BTL
Amplifier
2 x Low-Z
1 x Hi-Z
Limiter Limiter Limiter
Driver
Alignment
Driver
Alignment
Driver
Alignment
Driver
Alignment
Crossover Crossover Crossover Crossover
Gain Trim Gain Trim Gain Trim Gain Trim
Input
Sensitivity
Input
Gain
Input
Gain
Input
Selection
Input Setup
Zone Setup & Routing
Output Setup
Output 1 Output 2 Output 3 Output 4
Zone Adjustment Parameters Speaker Preset Parameters
5.4 Setup and Signal Routing
Thanks to their network based conguration features, CXA21K
and CXA215K ampliers offer considerable versatility in terms
of sources, signal routing, installation zones and output modes.
Inputs can be freely assigned to installation zones, and those zones
assigned freely to the available amplier outputs in either Lo-Z or
Hi-Z modes.
This versatility enables, for example, one amplier simultaneously
to drive both Lo-Z and Hi-Z speakers, or for different inputs to be
routed to different output zones.
The following paragraphs describe and illustrate the recommended
procedure for conguring input, zone and output routing. A general
signal ow schematic is also illustrated in Diagram 5O.

Conguration
5.4.1 Input Setup
Open the conguration Dashboard and select the Input Tab. The
Input Tab is shown in Diagram 5B.
• To edit default input names simply select and type in the Input
Name eld.
• Dene a mono or stereo input by selecting the appropriate
option. Dening a stereo input will reduce the total number of
discrete inputs available.
• Select an input sensitivity option from the drop-down menu:
+14dB, +4dB, -10dB and ‘microphone’ options are available.
Generally, the +14dB or +4dB options are appropriate
for ‘professional audio’ source hardware with balanced
outputs, while the -10dB option is more appropriate for
‘consumer audio’ source hardware with unbalanced outputs.
The ‘microphone’ option provides the signicantly greater
sensitivity required for microphones.
Note: Only dynamic microphones are suitable for connection.
Phantom power for condenser microphones is not provided.
• If necessary, adjust the input gain using the slider or up/down
icons. Gain adjustment is intended to be used for ne output
level adjustment following initial use.
5.4.2 Zone Setup & Routing
Open the conguration Dashboard and select the Zone Tab. The
Zone Tab is shown in Diagram 5E.
• Select the zone to be congured. The number of zones available
and their channel format (stereo or mono) will depend on the
amplier model, input setup and output mode (Lo-Z or Hi-Z).
For example, a two output amplier can have the following
zone congurations:
• 1 x stereo Lo-Z zone
• 2 x mono Lo-Z zones
• 1 x mono Hi-Z zone
• A four output amplier can have the following zones
congured:
• 2 x stereo Lo-Z zones
• 4 x mono Lo-Z zones
• 2 x mono Hi-Z zone
• 1 x mono Hi-Z zone + 1 x stereo Lo-Z zone
• 1 x mono Hi-Z zone + 2 x mono Lo-Z zones
Note: When congured in Hi-Z mode CXA21K and CXA215K
ampliers operate in ‘bridged’ mode where the output of two
channels is combined. This means that the number of output channels
available in Hi-Z mode is half that available in Lo-Z mode .
Note: Mono signals might be mono at source, created though
combining the left and right channels of a stereo signal (summed
mono) or treating the left and right channels of a stereo signal
independently (split mono).
• Name zones by typing in the Zone Name eld.
• Adjust the zone volume if required by using the slider.
• Dene a mono or stereo zone by selecting the appropriate
option. Dening a stereo zone will reduce the total number of
further zones available.
• Specify an input for the zone by selecting from the drop-
down menu. Selecting a stereo input for a mono zone will
automatically sum the stereo channels to mono.

Conguration
5.5 GPIO Setup and Connection
CXA21K and CXA215K ampliers provide a GPIO socket that
enables remote control of volume, standby, mute and trigger
functions. The GPIO connector pin functions are described in the
GPIO Settings menu illustrated in Diagram 5P. The connection
of GPIO based remote volume control and standby/mute are
illustrated in Diagram 5Q and Diagram 5R respectively.
Note: The GPIO connector must not be used for any unintended
purpose. Amplier damage may result from incorrect use of
GPIO.
Note: Shielded cable must be used when connecting standby
switches and potentiometers via GPIO.
Note: GPIO Pin 8 has a low output impedance and is able to
supply a maximum current of 10mA.
Note: GPIO Pin 1 and Pin 3 both offer ground connections:
Pin 1 is connected directly to the amplier chassis.
Pin 3 is connected to the chassis via a 220 Ohm resistor. The
‘soft ground’ connection of Pin 3 is potentially useful for
managing ground loops that may cause audible hum.
Diagram 5P
GPIO Settings Menu
Diagram 5Q
Potentiometer connections for remote volume
control via GPIO.
Note: Diagram 6D illustrates
use of the GPIO connector.
Diagram 5R
Connections for remote
standby/mute switch via GPIO.
Note: Diagram 6D illustrates
use of the GPIO connector.
Ground
+3V3
Expansion
Port
Ground
Standby/Mute
Expansion
Port
Linear Potentiometer
(>10kΩ)
Connect Wiper to
Pin 4, 5, 6 or 7. Switch open or closed toggles
Standby or Mute depending on
options selected in the GPIO
Settings Menu

Connections
6. Connections
CXA21K and CXA215K amplier rear panel connections
are illustrated in Diagrams 6A.
6.1 Mains Power Connection
CXA21K and CXA215K ampliers incorporate a power factor
corrected universal power supply and can be used with mains input
voltage from 100V AC to 240V AC, 50/60Hz. Use the mains cable
supplied with the amplier.
CXA21K and CXA215K ampliers incorporate a front panel
mounted power button. Press the button once to switch the
amplier on or off. Ensure that all signal, GPIO and output
connections are made before switching on the amplier.
6.2 Input Connection
All CXA21K and CXA215K amplier models provide four balanced
or unbalanced analog audio inputs and a stereo S/PDIF digital audio
input. Any input channel can be routed to any output channel.
Input routing options can be congured via the Control Web App
Input Tab. See Section 5 of this manual.
Analog Inputs
CXA21K and CXA215K analog inputs are of line level format
with a default input sensitivity of +4dBu (full output voltage
swing/sensitivity) in all output modes. Depending on the selected
sensitivity, the inputs can handle up to +24dBu without clipping.
Input sensitivity options can be set via the Control Web App Input
Ta b . See Section 5 of this manual.
Balanced input connections to the ampliers are made via male
‘Euro Block’ connectors. Connecting cables to the supplied female
input connectors is illustrated in Diagram 6B.
Unbalanced input connections to the ampliers are made via RCA
phono sockets connected in parallel with the balanced inputs.
Digital Outputs
Diagram 6A
CXA21K and CXA215K rear panel connections.
Note: Two output amplier model connection sockets differ only in
the deletion of channel 3 and channel 4 output connectors.
CXA21K and CXA215K Connect S/PDIF stereo digital audio output
connections are made via a single RCA Phono socket. The S/PDIF
output signal can be routed from any input or zone and is intended
to be used for daisy-chaining CXA21K and CXA215K Connect
ampliers.
Note: See the Output Routing paragraphs of Section 5.3.3 for more
information on Digital Output conguration.
Note: 75Ω RCA Phono cables specically intended for digital audio
should always be used for S/PDIF connections. Standard Phono cables
can be used but may not result in optimal performance.
Note: The S/PDIF output level is by default set at -10dB to reduce the
possibility of downstream input clipping.
6.3 Output Connections
Output connections from the ampliers are achieved via male
‘Euro Block’ connectors. Ensure that speaker connection polarity is
correct throughout the installation:
In the case of Lo-Z speaker connections, positive (+) amplier
terminals should always be connected to positive speaker terminals
and negative (–) amplier terminals always connected to negative
speaker terminals.
In the case of Hi-Z speaker connections, the two speaker cable
conductors should be connected between the positive (+) terminal
of Output 1 and the negative terminal (-) of Output 2, and likewise
for Outputs 3 and 4.
Output mode options (Lo-Z or Hi-Z) can be congured via the
Control Web App Input Tab. See Section 5 of this manual.
Connecting cables to the supplied female output connector is
illustrated in Diagram 6C.
Expansion
Port

Cable Gauge Table
Lo-Z installations, 0.5dB attenuation. 2 Ω, 4 Ω& 8 Ωloads
Cable Gauge Table
70V Hi-Z installations, 1.0dB attenuation
20 speakers evenly distributed
Cable Gauge Table
100V Hi-Z installations, 1.0dB attenuation
20 speakers evenly distributed
Cable Cross
Section
(mm2)
Cable Gauge
(AWG)
Max Cable
Length
(Metres, 2 Ω
load)
Max Cable
Length
(Metres, 4 Ω
load)
Max Cable
Length
(Metres, 8 Ω
load)
0.75 ≈18 N/A 5 10
1.5 ≈16 5 10 20
2.5 ≈14 8 17 35
4.0 ≈12 14 28 55
Cable Cross Section
(mm2)
Cable Gauge
(AWG)
Max Cable Length
(Metres),
(1000 W/channel)
Max Cable Length
(Metres),
(1200 W/channel)
0.75 ≈18 25 20
1.5 ≈16 50 40
2.0 ≈14 80 60
3.5 ≈12 125 100
Cable Cross Section
(mm2)
Cable Gauge
(AWG)
Max Cable Length
(Metres),
(1000 W/channel)
Max Cable Length
(Metres),
(1500 W/channel)
0.75 ≈18 50 30
1.5 ≈16 100 60
2.0 ≈14 160 100
3.5 ≈12 250 160
Connections
6.4 Speaker Cable Gauge
CXA21K and CXA215K speaker connection cable gauge
should be chosen appropriately to reect the type of
installation. The adjacent tables specify the appropriate
cable gauge and maximum cable length for less than 0.5dB
cable loss in Lo-Z mode and less than 1.0dB cable loss in
Hi-Z mode.
6.5 GPIO Connections
If any CXA21K and CXA215K GPIO functionality is
required, cables will need to be connected to the supplied
GPIO connector. Connecting cables to the GPIO connector is
illustrated in Diagrams 6D.
6.6 Network Connections
CXA21K and CXA215K ampliers are TCP/IP network
connected devices that are congured via a web page based
interface. Wired (Ethernet) and wireless (WiFi) connection
options are available. Connecting CXA21K and CXA215K
ampliers to a TCP/IP network is described in Section 5 of
this manual

Low-Z Mode
Hi-Z/BTL
Modes
5 mm
5 mm
5 mm
Connections
Diagram 6B
Balanced analog input
cable connections.
Diagram 6C
Output cable connections.