ALLEN & HEATH XB-14 MK2 (01) PDF Document

When you receive your ALLEN & HEATH XB-14 MK2, you should check that you have the following items:

• XB-14 MK2 MIXER

• Mains Lead (or leads) with the correct plug fitted

• This User Guide

• Type A-B USB Lead to connect the XB-14 to your computer

Before operating your ALLEN & HEATH XB-14 MK2, please read the following safety instructions:

Read instructions: Retain the safety and operating instructions for future reference and adhere to all warnings.

Do not remove cover: Operate the console with its covers correctly fitted.

Power sources: Connect the console only to a mains power unit of the type described in the User Guide and marked on the rear panel. Use the provided power cord with a sealed mains plug appropriate for your local supply.

Power cord routing: Route the power cord so it is not likely to be walked on, stretched, or pinched.

Grounding: This equipment must be earthed. Do not defeat the grounding and polarisation of the power cord plug.

Water and moisture: To reduce the risk of fire or electric shock, do not expose the console to rain or moisture or use it in damp or wet conditions. Do not place liquid containers on it.

Ventilation: Do not obstruct ventilation slots. If operated in a rack or flight case, ensure it is constructed to allow for adequate ventilation.

Heat and vibration: Locate the console away from excessive heat, direct sunlight, or any equipment that produces heat or causes excessive vibration.

Servicing: Switch off the equipment and unplug it immediately if it’s exposed to moisture, spilled liquid, damaged, or if smoke, odour, or noise is noticed. Refer servicing to qualified technical personnel only.

Installation: Install the console according to the User Guide. Do not connect the output of power amplifiers directly to the console. Use audio connectors and plugs only for their intended purpose.

If the mains plug on your ALLEN & HEATH XB-14 MK2 needs to be replaced, follow the wiring code below. This appliance must be earthed.

• The wire which is coloured Green and Yellow must be connected to the terminal in the plug which is marked with the letter E or with the Earth symbol.

• The wire which is coloured Blue must be connected to the terminal in the plug which is marked with the letter N.

• The wire which is coloured Brown must be connected to the terminal in the plug which is marked with the letter L.

Damage: To prevent damage, avoid placing heavy objects on the control surface, scratching it with sharp objects, or subjecting it to rough handling and vibration.

Environment: Protect the console from excessive dirt, dust, heat, and vibration. Avoid tobacco ash, smoke, drink spillage, and exposure to rain and moisture. If the console gets wet, switch it off, remove mains power immediately, and allow it to dry thoroughly before using again.

Cleaning: Avoid using chemicals, abrasives, or solvents. Clean the control panel with a soft brush and a dry, lint-free cloth. The faders, switches, and potentiometers are lubricated for life and do not require electrical lubricants. Knobs can be removed and cleaned with a warm soapy solution, then rinsed and dried completely before re-fitting.

Transporting: The console can be transported as a free-standing unit or mounted in a rack or flight case. Protect the controls from damage during transit and use adequate packing if shipping the unit.

Hearing: To avoid hearing damage, do not operate any sound system at excessively high volumes. This is especially important for close-to-ear monitoring like headphones. Continued exposure to high volume sound can cause hearing loss.

The pre-amps on the ALLEN & HEATH XB-14 MK2 use a two-stage design with carefully controlled gain. The key features are:

• When amplifying a signal from the XLR input, the gain range is a huge 69dB and is evenly distributed around the gain control for better signal level management.

• Most of the gain comes from the first stage, which helps keep unwanted noise to a minimum.

• There is no “pad” switch. Line level signals are plugged into the second stage of the pre-amp using the line input jack socket. This results in lower noise when using the line input, as it avoids the common practice of attenuating and then re-amplifying line signals.

The ALLEN & HEATH XB-14 MK2 has different EQ sections for different channel types:

• Mono Inputs: Equipped with a 3-band equaliser to cut sibilance or mic popping, or to adjust the tone of a presenter’s voice.

• Telco Channels: Fitted with a total cut high pass and low pass filter. This allows you to eliminate the top or bottom end of the channel’s frequency response, which is useful for low-quality telephone line connections.

• Stereo Channels: Feature high and low frequency tone controls designed for use with music.

The ALLEN & HEATH XB-14 MK2 features several dedicated buses for flexible audio routing:

AUX bus: A single Auxiliary bus that can be used for external processing, effects, recording, or auditioning.

MIX B: A separate stereo mix bus, independent from the main program mix. It can be used for recording an independent mix or creating a clean feed source with selected channels.

Audition bus: A dedicated stereo audition bus for auditioning or off-air recording. Pressing the AUD button on a channel transfers its mix from the main program feed to the audition bus.

Each channel on the ALLEN & HEATH XB-14 MK2 has a dual-indicator system to monitor signal levels. The signal is monitored pre-fader and pre-ON switch.

• The Signal LED shows if there is a signal present on the channel, allowing the operator to see which channels are active.

• The Peak LED provides a warning if a channel’s signal is in danger of exceeding its peak level and clipping.

The ALLEN & HEATH XB-14 MK2 includes several remote control features designed for broadcast environments:

• Mono mic/line channels have fader start logic switching to control external equipment or automatically mute speaker outputs, preventing acoustic feedback.

• Stereo channels have start & cue logic outputs to connect to external equipment like CD players for transport control.

• There is an option to remotely mute the mono inputs using an external “cough” switch or similar device.

Operating Levels

THD+n

USB Audio CODEC (Coder/Decoder)

Noise

Headroom

Crosstalk & Attenuation (dB 22-22kHz)

Frequency Response

Dimensions and Weight

Each mono input channel on the ALLEN & HEATH XB-14 MK2 has the following controls and connectors:

Mic Input Socket: Standard 3-Pin XLR socket (Pin 1=Chassis, Pin 2=hot (+), Pin 3=Cold (-)).

Line Input Jack Socket: Standard 1/4″ (6.25mm) jack for balanced or unbalanced line level signals (Tip=Hot (+), Ring=cold (-), Sleeve=Chassis). The Line input overrides the Mic input.

Insert Jack Socket: Standard 1/4″ (6.25mm) jack for unbalanced insert send and return signals (Tip=send, Ring=return, Sleeve=Chassis). Nominal level is 0dBu. The insert point is post-filter and pre-EQ.

Gain Control: Adjusts the gain of the input amplifier. Varies from -6dB to +63dB for the Mic Input, and -10dB to +26dB for the Line input.

100Hz High Pass Filter: A 2-pole (12dB per octave) filter to reduce pop noise and rumble from microphone signals from both Mic and Line inputs.

HF EQ: Affects higher frequencies, with a corner frequency of 12kHz and +/-15dB of boost/cut.

MF EQ: Affects mid-range frequencies. The frequency sweep control selects the centre frequency from 120Hz to 4kHz.

LF EQ: Affects low frequencies, with a corner frequency of 80Hz and +/-15dB of boost/cut.

Aux: Sends a signal to the auxiliary bus. Can be set pre- or post-fade. Varies from off to +6dB.

MIX B: Routes the post-fade channel signal to the independent stereo MIX B bus.

PAN: Adjusts the signal’s position between the left and right sides of the PGM, Audition, and MIX B buses.

AUDITION: Switches the post-fade signal from the program bus to the audition bus.

ON Switch: Mutes or un-mutes the channel signal to the PGM, Audition, MIX B, and Aux buses. Can be remotely muted.

PFL Switch: (Pre-Fade Listen) Sends the channel signal to the headphones/CRM and main L-R meters for checking audio before fading up.

Fader: A 100mm fader controlling the level to the PGM, Audition, MIX B, and post-fade Aux buses. Includes Fader Start logic.

The TELCO channels on the ALLEN & HEATH XB-14 MK2 are specifically designed for telephone communication (e.g., call-ins). Here’s how to use their features:

TEL IN: XLR input for the telephone communication signal (Pin 1=Chassis, Pin 2=hot, Pin 3=Cold).

CLF OUT: XLR output for the Clean-Feed signal back to the telephone line, preventing the caller from hearing an echo of their own voice.

TELCO Input Gain: Varies the gain applied to the TELCO input from -10dB to +26dB.

TELCO Channel Filters: A high pass filter (20Hz to 6kHz) and a low pass filter (20kHz to 700Hz) to narrow the frequency range and improve clarity from a telephone line.

TALK: Enables the presenter/operator to communicate with the caller off-air without their voice going to the main program mix. The talk source is a pre-selected mono channel.

CLF SCE (Clean-Feed Source): Selects the source for the clean-feed output. By default (buttons up), it’s the main PGM mix minus the TELCO channel’s own input. You can also select the AUX or AUDITION bus as the source.

Other controls like AUX, MIX B, PAN, AUDITION, ON Switch, PFL, and Fader function similarly to the mono channels but are tailored for the TELCO signal.

The stereo input channels (ST1 & ST2, ST3 & ST4) are designed for line-level stereo sources like CD players or computers. Here are the key features:

Inputs: Each channel strip has dual inputs (e.g., ST1 and ST2) that can be selected. ST1/ST3 use 1/4″ balanced jack sockets, while ST2/ST4 use unbalanced RCA phono sockets.

Stereo source selector switch: A button with a green LED selects which input (e.g., ST1 or ST2) is active for that channel strip.

Stereo input level controls: Adjusts the input gain from fully attenuated to +15dB.

Stereo channel EQ: A 2-band EQ with corner frequencies of 12kHz for HF and 80Hz for LF.

BAL (Balance control): Adjusts the relative levels of the left and right signals sent to the mix buses.

ON (+START/CUE) switch: Mutes the channel and also activates the START/CUE logic signals on the remote interface connector for controlling external playback devices.

The AUX, MIX B, AUDITION, PFL, and Fader controls function similarly to those on the mono channels, but are adapted for stereo signals. There is no fader start logic on the stereo channel faders.

The ALLEN & HEATH XB-14 MK2 features a built-in USB audio interface for connecting to a computer (Windows or Mac).

Connection: It uses a standard USB “B Type” connector and is a USB 1.1 compliant stereo CODEC, also fully compliant with USB 2 ports. It uses standard operating system drivers, so no special installation is needed.

USB Return (Input from Computer): The audio from the computer is returned to the mixer on stereo input ST6. The level is controlled by the USB RTN (ST6) knob. This signal can then be routed to stereo channel 4 (ST4) by selecting ST6 as the source for that channel.

USB Send (Output to Computer): You can select the audio source to send to the computer using the USB SOURCE SELECT switches. If no switches are pressed, the post-fader main program mix is sent. Alternatively, you can select the MIX B bus, Audition bus, or a mono mix of the AUX and PGM Mono buses.

When connecting the USB audio interface of your ALLEN & HEATH XB-14 MK2, please note the following for different operating systems:

Windows XP/Vista: If the volume level from the computer is low or inaudible after plugging in the mixer, check the device volume in Control Panel > Sounds and Audio Devices > Volume. Set the device volume to High.

Windows 7: Windows 7 may treat the USB audio device as a microphone source instead of a line input. This can result in a very high input level. To correct this, set the device volume level much lower; a setting of 3 is recommended as a starting point.

The Master Section contains the main output controls, monitoring, and metering for the ALLEN & HEATH XB-14 MK2.

Main Left & Right meters: 12-segment LED meters show the level of the selected monitor source. The ‘0’ position corresponds to +4dBu at the main outputs.

CRM + PHONES Source Selector: These 5 switches select the audio source for the control room speakers, engineer’s headphones, and meters. They work on a priority basis (the switch nearest the meters takes priority). If all are un-pressed, the main PGM mix is monitored.

GUEST PHONES Source Selector: Similar switches that select the source for the two guest headphone outputs, allowing guests to listen to a different source than the operator.

TALK TO GUEST switch: Allows the operator to speak to the guests’ headphones using the pre-selected comms mic channel.

CRM Speakers level: Adjusts the volume of the control room speakers.

DIM & Cut CRM Speakers: The DIM switch reduces speaker volume by 20dB. The CUT SPKS LED illuminates when the speakers are muted, which can happen via the remote interface or the MIC FADER UP feature.

MIC FADER UP = CUT Speakers: An under-panel switch that enables automatic muting of the control room speakers when any mono channel fader is raised, preventing feedback.

Headphone Level Controls: Separate knobs for the Control Room (engineer) phones and Guest phones.

Level Controls (EX MON, MIX B, AUD): Master level controls for the External Monitor input, MIX B bus output, and Audition bus output.

Program Mix Fader: The main 100mm fader that controls the level of the stereo PGM output.

48v Phantom Power switch: Applies 48v power to the 4 Mic input XLR connectors for condenser microphones.

The ALLEN & HEATH XB-14 MK2 has two 15-way D-socket connectors (REMOTE A and REMOTE B) for remote control functions. The outputs are open collector.

REMOTE A Connector

This connector is for “Fader Up” logic signals from mono/telco channels and remote muting.

REMOTE B Connector

This connector provides Start/Stop (Cue) logic pulses from the Stereo channel ON switches to control playback devices.

The Start/Cue logic is designed to interface with a common standard on equipment like Denon and Pioneer, typically using a 2-pole 3.5mm jack plug (tip=start, sleeve=stop/cue).

The tiny slide switches on the rear panel of the ALLEN & HEATH XB-14 MK2 allow you to configure the behavior of the channel ON switches.

Standard Operation (Switch Up): The channel ON switch functions as a normal ON/OFF mute switch.

Jammed ON (Switch Down): Moving a slide switch down for a specific channel disables its corresponding ON switch, making the channel permanently ON. The green LED in the switch will be permanently illuminated.

There are also special options for the four stereo channels:

• Disable Mute but Retain LED function: A dedicated switch can disable the mute circuit for all 4 stereo channels, but the LEDs will still follow the ON switch presses. This is useful if you are using the ON switches for Start/Cue transport control but don’t want to accidentally mute the audio.

• Individual Stereo Channel Jammed ON: You can use the individual STEREO INPUTS 1, 2, 3 & 4 slide switches to make a specific stereo channel permanently on, including its LED illumination.

You can use the Audition bus on the ALLEN & HEATH XB-14 MK2 to record an interview with a telephone caller off-air while playing music on the main program mix. The recording can be captured from the Audition Out phono connectors or via the USB port.

Step 1. Ensure the Audition buttons are pressed (and lights are on) for the channels you want to record off-air (e.g., the presenter’s microphone channel and the TELCO channel).

Step 2. On the TELCO channel, switch the CLF SCE (Clean-Feed Source) for the caller to Audition. This sends the audition mix back to the caller so they can hear the presenter.

Step 3. If recording to a computer, select Audition as the source for the USB send using the USB SOURCE SELECT buttons.

Step 4. The producer/operator can monitor either the live program or the off-air interview by using the CRM + PHONES selection switches to toggle between the PGM mix and the Audition bus.

Yes, the ALLEN & HEATH XB-14 MK2 can be fitted into a 19″ rack or incorporated into studio furniture using an optional 19″ rack fixing kit. The part number for the rack mounting kit is: ZED1402-RK19.

CAUTION: These servicing instructions are for use by qualified service personnel only. To reduce the risk of electric shock do not perform any servicing other than that contained in the operating instructions unless you are qualified to do so. We advise that these modifications be carried out by an authorised Allen & Heath service centre.

The ALLEN & HEATH XB-14 MK2 offers several internal modification options:

AUX Pre ON switch / Pre fade option: (Mono, Telco, stereo channels) A cut and solder link changes the AUX pre-switch source. The default is pre-fade (after the ON switch). The option sources the signal pre-ON switch (post-EQ).

Audition fader start option: (Mono, telco channels only) A cut and solder link. By default, fader start is disabled when a channel’s Audition button is pressed. Modifying this link enables fader start even when Audition is active.

Stereo channel input option: (Channels ST1-3 only) Moving internal jumpers allows the dual stereo sources for a channel to be mixed together instead of selected, with the channel fader controlling both inputs.

Program fader bypass: (Mix PCB) Moving two jumpers bypasses the main program fader, fixing its level and preventing it from being accidentally moved.

CRM / Guest additive mix option: (Master & meter PCBs) Bridging solder links changes the monitor source selection from priority mix (default) to additive mix, where multiple sources can be monitored simultaneously.

Mix B / Rec out solder option: (Distribution PCB) A cut and solder link changes the Mix B output phono sockets to a pre-fader program mix for recording purposes.

Comms mic mix option: (Logic PCB) Cutting or adding wire links determines which microphone channel(s) are used as the source for the TALK buttons. The default is M1.

Mic fader mute option: (Logic PCB) Cutting or adding wire links selects which microphone channels will mute the control room speakers when their fader is raised (and the ON switch is pressed). The default is all mic channels.