Allen & Heath MixWizard WZ4 16:2 and WZ4 12:2 User Guide

Limited One Year Warranty

This product is warranted to be free from defects in materials or workmanship for a period of one year from the date of purchase by the original owner. To ensure a high level of performance and reliability, read this User Guide before operating. In the event of a failure, notify and return the defective unit to ALLEN & HEATH Limited or its authorised agent as soon as possible for repair under warranty, subject to the following conditions:

• The equipment has been installed and operated in accordance with the instructions in this User Guide.
• The equipment has not been subject to misuse, neglect, or alteration other than as described in the User Guide or Service Manual, or approved by ALLEN & HEATH.
• Any necessary adjustment, alteration, or repair has been carried out by ALLEN & HEATH or its authorised agent.

This warranty does not cover fader wear and tear. The defective unit is to be returned carriage prepaid to ALLEN & HEATH or its authorised agent with proof of purchase. Units returned should be packed to avoid transit damage. In certain territories, the terms may vary; check with your ALLEN & HEATH agent for any additional warranty that may apply.

This product complies with the European Electromagnetic Compatibility directive 2004/108/EC and the European Low Voltage directive 2006/95/EC.

This product has been tested to EN55103 Parts 1 & 2 2009 for use in Environments E1, E2, E3, and E4 to demonstrate compliance with the protection requirements in the European EMC directive 2004/108/EC. During some tests, the specified performance figures of the product were affected. This is considered permissible, and the product has been passed as acceptable for its intended use. Allen & Heath has a strict policy of ensuring all products are tested to the latest safety and EMC standards. Customers requiring more information about EMC and safety issues can contact Allen & Heath.

NOTE: Any changes or modifications to the console not approved by Allen & Heath could void the compliance of the console and therefore the user's authority to operate it.

Allen & Heath WZ4 16:2 and 12:2 User Guide AP8665 Issue 1. Copyright © 2013 Allen & Heath Limited. All rights reserved.

Allen & Heath Limited, Kernick Industrial Estate, Penryn, Cornwall, TR10 9LU, UK.

Website: www.allen-heath.com

Safety Instructions

WARNING - Read the following before proceeding:

CAUTION: RISK OF ELECTRIC SHOCK DO NOT OPEN

ATTENTION: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR

• Read instructions: Retain these safety and operating instructions for future reference. Adhere to all warnings printed here and on the console. Follow the operating instructions printed in this User Guide.
• Do not remove cover: Operate the console with its covers correctly fitted. Disconnect mains power by unplugging the power cord if the cover needs to be removed for setting internal options. Refer this work to competent technical personnel only.
• Power sources: Connect the console to a mains power unit only of the type described in this User Guide and marked on the rear panel. Use the power cord with a sealed mains plug appropriate for your local mains supply as provided with the console. If the provided plug does not fit into your outlet, consult your service agent for assistance.
• Power cord routing: Route the power cord so that it is not likely to be walked on, stretched, or pinched by items placed upon or against it.
• Grounding: Do not defeat the grounding and polarisation means of the power cord plug. Do not remove or tamper with the ground connection in the power cord. WARNING: This equipment must be earthed.
• 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 containers of liquids on it which might spill into any openings.
• Ventilation: Do not obstruct the ventilation slots or position the console where the air flow required for ventilation is impeded. If the console is to be operated in a rack unit or flightcase, ensure that it is constructed to allow adequate ventilation.
• Heat and vibration: Do not locate the console in a place subject to excessive heat or direct sunlight as this could be a fire hazard. Locate the console away from any equipment which produces heat or causes excessive vibration.
• Servicing: Switch off the equipment and unplug the power cord immediately if it is exposed to moisture, spilled liquid, objects fallen into the openings, the power cord or plug become damaged, during lightning storms, or if smoke, odour, or noise is noticed. Refer servicing to qualified technical personnel only.
• Installation: Install the console in accordance with the instructions printed in this User Guide. Do not connect the output of power amplifiers directly to the console. Use audio connectors and plugs only for their intended purpose.

Important Mains Plug Wiring Instructions

The console is supplied with a moulded mains plug fitted to the AC mains power lead. Follow the instructions below if the mains plug has to be replaced. The wires in the mains lead are coloured in accordance with the following code:

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. This appliance must be earthed. 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. Ensure that these colour codes are followed carefully in the event of the plug being changed.

General Precautions

• Damage: To prevent damage to the controls and cosmetics, avoid placing heavy objects on the control surface, scratching the surface with sharp objects, or rough handling and vibration.
• Environment: Protect from excessive dirt, dust, heat, and vibration when operating and storing. Avoid tobacco ash, smoke, drinks spillage, and exposure to rain and moisture. If the console becomes wet, switch off and remove mains power immediately. Allow to dry out thoroughly before using again.
• Cleaning: Avoid the use of chemicals, abrasives, or solvents. The control panel is best cleaned with a soft brush and dry lint-free cloth. The faders, switches, and potentiometers are lubricated for life. The use of electrical lubricants on these parts is not recommended. The fader and potentiometer knobs may be removed for cleaning with a warm soapy solution. Rinse and allow to dry fully before refitting them.
• Transporting: The console may be transported as a free-standing unit or mounted in a rack or flightcase. Protect the controls from damage during transit. Use adequate packing if you need to ship the unit.
• Hearing: To avoid damage to your hearing, do not operate any sound system at excessively high volume. This also applies to any close-to-ear monitoring such as headphones. Continued exposure to high volume sound can cause frequency selective or wide range hearing loss.

Introduction

Welcome to the Allen & Heath WZ4, the latest generation of the popular MixWizard series of compact audio mixing consoles. This user guide is intended to be brief and to the point. Please read it fully before starting. Included is information on installing, connecting, and operating the console, panel drawings, system block diagrams, and technical specifications. For further information on the basic principles of audio system engineering, please refer to specialist publications and resources available from bookshops, audio equipment dealers, and the Internet.

While the information in this guide is believed to be reliable, Allen & Heath does not assume responsibility for inaccuracies. They also reserve the right to make changes in the interest of further product development.

Allen & Heath offers further product support through its worldwide network of approved dealers and service agents. You can also access their website on the Internet for information on their full product range, company pedigree, assistance with technical queries, contact details, or to simply chat about audio matters (www.allen-heath.com). To help provide the most efficient service, please keep a record of your console's serial number, and date and place of purchase to be quoted in any communication regarding this product.

Contents

• Warranty ............................................................. 2
• Safety Instructions ............................................. 3
• General Precautions ......................................... 4
• Introduction to this Guide .............................. 5
• Front Panel Layout ............................................ 6
• Introducing the MixWizard............................. 7
• Installing the Console ....................................... 8
• Connecting Power ............................................ 9
• Connection Pinouts and Cables...................10
• Audio Connections ......................................... 11
• Connector Panel Layouts .............................. 12
• Console Connectors ...................................... 13
• Mono Input Channel.......................................15
• Stereo Input Channel ..................................... 17
• Stereo Effects Channel ................................... 18
• Master Section ................................................. 19
• Gain Structure..................................................21
• Specifications .................................................... 22
• System Block Diagrams..................................24
• User Options....................................................26
• Cue Sheets ........................................................ 29

Introducing the MixWizard

The Allen & Heath MixWizard series of consoles includes several models. This user guide describes the WZ4 16:2 and WZ4 12:2 stereo models. For further information on the MixWizard series, please refer to the Allen & Heath web site.

The MixWizard is a compact console designed for professional live sound mixing. It is built to the same high standards as Allen & Heath's top-of-the-range consoles, featuring individual circuit cards, potentiometers nutted to the panel for absolute strength, a steel chassis, and a no-compromise circuit design ensuring the finest sonic performance.

The console can be operated free-standing or in a 19" rack or flightcase. It is supplied with protective side trims fitted, which can be removed for rack mounting. The rear connector pod can be easily rotated for rear-facing or underside connectors when rack-mounted.

Both models feature a 4-band semi-parametric EQ and a high-pass filter per mic/line channel, 6 aux sends with combinations of pre/post switching, 100mm faders, a built-in dual effects processor with adjustable parameter control, a dedicated mono output with separate fader, an innovative operating mode for aux-fed sub systems, an additional AB stereo output, comprehensive metering, engineers monitoring, and a lamp socket.

The WZ4 16:2 provides 16 mono mic/line inputs and 2 stereo return inputs, for a total of 20 input connections. The WZ4 12:2 provides 8 mono mic/line inputs, 2 full-channel dual stereo inputs, and 2 stereo return inputs, for a total of 20 input connections.

The base of the console can be removed to access a host of internal user-selectable options. These set user preference for the aux, direct output, and AB sources.

The aux outputs are impedance-balanced but may be electronically balanced if required by fitting an optional part. A kit is also available to fit an optional USB2 output card, which allows the console to be linked to a computer for multitrack recording.

An Allen & Heath LEDlamp gooseneck lamp with a built-in dimmer can also be added for lighting the console in low-light conditions.

Installing the Console

Free Standing

The console is supplied ready for free-standing operation with its side trims fitted and connector pod positioned for rear access. If converting from rack to free-standing, ensure the pod is correctly rotated and secured, and the side trims are fitted as shown.

19" Rack Mount

For rack mounting, remove the two side trims and rotate the pod into the preferred connector position. Allow enough space for the cables and connectors behind the console.

Important Notes:

• Do not transport the console with its connector pod securing screws removed.
• Do not attempt to remove the connector pod from the console.
• Do not obstruct the ventilation slots. Allow adequate space around the console for air flow.
• If the side trims are to be removed, do not refit their fixing screws to the unit. Retain and store these in case the trims need to be refitted in the future.

Connecting Power

WARNING: For operator safety, do not remove the ground (earth) connection in the power lead of the console or connected equipment.

Read and understand the Important Safety Instructions printed at the start of this guide, and the warnings printed on the rear of the console. Check that your local mains supply is within the 100-240V operating voltage range allowed. Check that the correct mains lead with a moulded plug has been supplied with your console. Make sure that the IEC mains plug is pressed fully into the panel socket before switching on.

Grounding

The connection to ground in an audio system is important for two reasons:

1. SAFETY: To protect the operator from high voltage electric shock.
2. AUDIO PERFORMANCE: To minimise the effect of ground (earth) loops which result in audible hum and buzz, and to shield the audio signals from interference.

For safety, it is important that all equipment grounds are connected to mains ground so that exposed metal parts are prevented from carrying high voltage which can injure or even kill the operator. Do not disconnect the ground connection in the mains lead. It is recommended that the system engineer check the continuity of the safety ground from all points in the system, including microphone bodies, turntable chassis, equipment cases, rack metalwork, and so on.

Switching the Console On and Off

It is good practice to turn power amplifiers off before switching the console and any other connected equipment on or off. This prevents any unexpected clicks or thumps when the equipment is powered up.

Turn amplifiers and powered speakers on last and off first.

To turn the console on, press the ON/OFF switch next to the IEC mains input socket. To turn the console off, press this switch again.

Connection Pinouts and Cables

The MixWizard uses professional grade 3-pin XLR and 1/4" TRS (3-pole) jack sockets. To ensure best performance, use high-quality audio cables and connectors, and take time to check for reliable and accurate cable assembly. Faulty or substandard interconnecting leads are a common cause of audio system problems.

Connector Types:

• XLR Female Plug: For balanced microphone or line inputs.
• XLR Male Plug: For balanced outputs.
• TS Jack Plug (2-pole): For unbalanced mono signals.
• TRS Jack Plug (3-pole): For balanced mono or stereo signals, or insert send/return.
• RCA Phono Jacks: For unbalanced line level signals (e.g., CD players, tape decks).

Cable Wiring Notes:

• Balanced Connections: Use 3-pin XLR or TRS connectors. Ensure correct wiring (Pin 2/Tip = Hot, Pin 3/Ring = Cold, Pin 1/Sleeve = Ground). Avoid reversing + and - on balanced connections, as this will result in reversed polarity (out-of-phase) signals which may cause signal cancellation effects.
• Unbalanced Connections: Use TS jacks or 2-wire (signal, ground) cables with XLR or TRS connectors. For unbalanced signals, typically connect the signal wire to Pin 2/Tip and the ground to Pin 1/Sleeve. For longer cable runs, balanced interconnections should always be used. Line-level interconnections between unbalanced equipment and the console are unlikely to cause problems if cables are kept shorter than 10 meters.

Dealing with Ground Loops, Buzz and Interference:

For optimum performance, all audio signals should be referenced to a solid, noise-free ground (earth) point, often referred to as the 'star point' or 'clean earth'. A ground loop is created when potential differences exist between grounds at different points in the system, and the signal has more than one path to ground. In most cases, ground loops do not result in audible problems. If you experience hum or buzz caused by a ground loop:

1. Check that each piece of equipment has its own separate path to ground.
2. Operate ground lift switches on connected equipment according to their manuals.
3. Alternatively, disconnect the cable screen at the destination end only. This breaks the offending loop while maintaining signal shielding down the length of the cable.

WARNING: For operator safety, do not remove the ground (earth) connection in the power lead of the console or connected equipment.

To avoid interference pickup, keep audio cables away from mains power units and cables, thyristor dimmer units, computer equipment, and mobile phones. Where this cannot be avoided, cross the cables at right angles to minimise interference.

Balanced Connections Explained:

A differentially balanced connection uses two signal wires (+hot, -cold) and a shield. The source sends a positive polarity down the + wire and negative down the - wire. The destination input stage accepts the + signal on its non-inverting (+) input pin and inverts the - signal, adding it to the + signal, boosting the wanted signal. When unwanted interference (hum and noise) is induced into the cable, it affects both wires equally and with the same polarity. At the destination input, the - wire signal gets inverted and added to the + signal. Because the polarity is the same on both input wires, the noise cancels itself out. For this interference rejection to work, the source, cable, and destination input must all be balanced. Balancing provides the greatest advantage with low-level signals such as those produced by microphones.

An impedance-balanced output provides similar interference rejection but without the signal drive on the - wire. The - wire has no signal but is held at the same impedance as the + wire. This means both wires pick up noise equally, resulting in cancellation.

Connector Panel Layouts

Diagrams illustrating the rear panel layouts for the WZ4 16:2 and WZ4 12:2 models are provided, showing the placement of various input, output, and connection sockets.

The Console Connectors

MIC / LINE IN

The channel PAD (LINE) switch selects either the MIC XLR or the LINE TRS jack as the input source. The XLR is normalled through the TRS jack, meaning the XLR can be used for microphone or line-level signals when nothing is plugged into the jack socket. Both inputs are balanced but can be wired to work with unbalanced signals when required.

WARNING: Do not connect unbalanced sources or cables to the XLR input when 48V phantom power is selected. To avoid loud clicks, always mute the channel before switching +48V on or off, and when plugging or unplugging cables.

STEREO LINE IN

The WZ4 12:2 has six stereo inputs: four channel inputs (ST1,3 unbalanced; ST2,4 balanced) and two stereo returns (ST5 balanced, ST6 unbalanced). The WZ4 16:2 has two stereo return inputs (ST1 balanced, ST2 unbalanced). All inputs use TRS jacks. Unbalanced inputs automatically connect the TRS ring to ground for working with balanced sources. The L input is normalled through the R input to accept mono signals.

Note: The ST5 (WZ4 12:2) or ST1 (WZ4 16:2) stereo return input mixes with the internal effects processor return. This allows an external effects device fed from a different aux mix to combine with the internal processor, saving input channels. Alternatively, the internal unit can be turned off, and the ST5 (ST1) input used with an external unit.

INSERT

A single 3-pole TRS jack carries the unbalanced insert signal. Tip = send, Ring = return, Sleeve = common ground. The channel insert is post-HPF, pre-EQ and operates at 0dBu. The LR mix insert is pre-fader and operates at 2dBu. These are suitable for line-level signal processing equipment like compressors, outboard EQs, and delay units.

DIRECT OUTPUT

The mic/line channel direct output is available on an impedance-balanced TRS jack, operating at 0dBu line level. The source is set using an internal option jumper for each channel. The factory default setting is pre-fade (following the pre/post-EQ setting), but this can be changed to post-fade if preferred.

Direct outputs are useful for multitrack recording, allowing fader movements during a live show not to affect the recording. They can also be used for channel effects sends, freeing up aux mixes for other purposes.

L, R, M OUT

The main console mix outputs are on balanced XLR, producing +4dBu when meters read '0'. The M output can be switched to provide a mono sum of the post-fade L and R signals, or the AUX6 output.

The L and R outputs typically feed the house PA system or a 2-track recorder. The M output can provide an additional feed for a mono fill speaker or zone, or serve as the main feed into a mono PA. When used with a mono PA, the L and R mix can provide a pair of subgroups. Configured for the AUX6 mix, the M output is ideal for driving a sub bass speaker system when working with an 'aux-fed subs' PA, providing its own per-channel mix on balanced XLR with a dedicated fader for house volume control.

AB OUT

A pair of impedance-balanced TRS jacks can be configured as an additional LR mix or engineers' monitor send, operating at -2dBu line level. A front panel recessed 'mode' switch determines the source: it can follow the console monitor system (feeding an independent local stereo monitor or engineers' wedge speaker) or the LR mix (defaulting to post-LR fader). An internal option jumper allows changing this to pre-LR fader.

The AB output offers possibilities for independent 2-track recording feeds, broadcast feeds, zone and delay fill feeds, local monitor feeds, and more.

AUX OUT 1-6

Each aux send is available on an impedance-balanced TRS jack operating at -2dBu line level. An optional balanced line driver IC can be fitted to provide an electronically balanced output at +4dBu. This option is usually not necessary, as the impedance-balanced drive provides significant interference rejection when feeding balanced equipment inputs.

Aux sends are typically used to feed stage monitors, effects devices (reverb, delay), and for special mix requirements.

FOOTSWITCH

Mutes and unmutes the ST5 (ST1) effects return channel, ideal for bypassing effects between songs. This affects both the internal processor and any external effects device plugged into these return inputs. Use a momentary or latching footswitch. Shorting a TS or TRS jack tip to sleeve turns the mute on.

USB II OPTION

A blank plate is fitted here as standard. A USB II option kit is available from Allen & Heath. Refer to OPTIONS later in this guide.

The MONO Input Channel

+48V: Switches +48VDC to the channel input XLR for powering microphones or DI boxes that need phantom power. The power is current-limited through 6k8 ohm resistors to pins 2 and 3.

WARNING: Do not connect unbalanced sources or cables to inputs with phantom power selected. To avoid loud clicks, always mute the channel before switching +48V on or off, and when plugging or unplugging microphones.

PAD (LINE): Press this switch to select the channel TRS jack LINE input. Release the switch to select the XLR MIC input. The XLR normals through the TRS socket. With nothing plugged into the line input, this switch acts as a 20dB PAD for the mic XLR, attenuating the input signal for high-level microphone or line sources.

GAIN: Adjusts input sensitivity to match the connected source to the internal 0dBu operating level. Provides a variable 50dB range (+10 to +60dB for mic, or -10 to +40dB for line with pad selected). Set gain using PFL so that console meters average '0' with loudest moments at '+6'. Reduce gain if red peak indicators light. Peak indicators light 5dB before actual clipping.

HPF: Switches in the channel high-pass filter, attenuating frequencies below 80Hz by 12dB per octave. The filter is pre-insert, pre-EQ. Use the HPF to reduce low-frequency noise like microphone popping, stage noise, and tape transport rumble.

EQ: A 4-band semi-parametric EQ offers independent control. HF and LF are shelving filters affecting frequencies above 12kHz and below 80Hz, respectively. HM and LM are bell-shaped peak/dip filters with a centre frequency sweep (500Hz-15kHz for HM, 35Hz-1kHz for LM) and a width (Q) of 1.8. All bands can be boosted or cut by up to 15dB, with a centre detent at 0dB.

For best microphone selection and placement, start with the EQ flat and apply boost or cut only as needed. Use the EQ IN button to compare with a flat response. For problem frequencies, cut rather than boost where possible.

[EQ frequency response graphs are described here]

Mono Input Channel Controls

AUX SENDS: Rotary controls adjust the amount of channel signal mixed to aux outputs. Each of the 6 auxes has its own control, adjusting from fully off to +6dB boost (unity gain 0dB at 3 o'clock). Factory default settings are typically suitable. Pre-fade aux options are Pre-INSERT, pre-EQ, post-MUTE.

PRE: When pressed, the pre-fade channel signal is sent to the associated auxes. When released, the post-fade signal is sent. Auxes 3 and 4 are affected by the PRE switch by default; this can be changed to dedicated pre-fade via internal options.

PAN: Positions the channel signal between L and R in the stereo mix. The centre position (mono image) is detented for quick resetting.

MUTE: When pressed, the channel signal is turned off. This affects feeds to the LR mix, pre and post-fade aux sends, and direct output, but not the insert send. A red indicator lights when muted.

PFL: Press PFL to listen to the pre-fade channel signal in headphones or AB monitor without affecting main outputs. Console main LR meters are interrupted by the channel signal. The red PK indicator lights when PFL is selected. Selecting multiple PFLs mixes their signals in the monitor.

PEAK: Red indicator illuminates when the channel pre-fade signal is within 5dB of clipping, warning to reduce GAIN before distortion.

SIGNAL: Green indicator lights when the channel pre-fade signal is greater than -12dBu.

FADER: Controls the channel level feeding the main LR mix and post-fade aux sends. It also affects the direct output if set to post-fade. Provides +10dB maximum boost above its unity gain 0dB position.

Important Note on Setting Channel Levels: Use PFL to set GAIN controls for correct signal level. Use faders to balance signals in the mix, typically operated around -20 to 0 positions. Avoid setting faders to '0' and mixing using GAIN controls.

The STEREO Input Channel (WZ4 12:2 only)

Dual stereo inputs: Each of the two stereo channels has two inputs that can be used separately, mixed, or split. This is useful for mixing multiple sound effects playback devices or reverb returns into one channel, saving console space. The L input signal normals through the R input socket, allowing a mono source to feed both left and right sides of the stereo channel.

ST1 (ST3): Unbalanced TRS inputs. GAIN control adjusts from fully off to +16dB. Press the ST1 (ST3) switch to turn the input on.

Routing mode switch: A recessed switch prevents accidental operation. In the normal up position, the ST1 (ST3) signal mixes with ST2 (ST4) into the stereo channel. When pressed, the signal routes direct to the LR mix instead of the channel, allowing use as simple stereo returns, providing four independent stereo sources to the LR mix.

ST2 (ST4): Balanced TRS inputs. GAIN control adjusts from fully off to +16dB. Press the ST2 (ST4) switch to turn the input on. These inputs always feed the stereo channels.

EQ: A 4-band fixed-frequency EQ provides independent control. HF and LF are shelving filters (affecting frequencies above 12kHz and below 80Hz, respectively). HM and LM are bell-shaped peak/dip filters centred around 2.5kHz and 250Hz, respectively, with a width (Q) of 1.8. All bands can be boosted or cut by up to 15dB, with a centre detent at 0dB.

AUX SENDS: Work as described for the mono channel. L and R sides of the stereo signal sum together to feed each aux in mono. This can be changed via an internal solder option so that L feeds auxes 1,3 and R feeds auxes 2,4.

BAL: Balances the level of the L signal against the R signal to compensate for differences or position the signal within the stereo image. The centre equal level position is detented.

MUTE: When pressed, the channel signal is turned off, affecting feeds to the LR mix and aux sends. A red indicator lights when muted.

PFL: Press PFL to listen to the summed L+R pre-fade channel signal in headphones or AB monitor without affecting main outputs. Console main LR meters are interrupted. The red PK indicator lights when PFL is selected.

PEAK: Red indicator illuminates when the channel pre-fade signal is within 5dB of clipping, warning to reduce GAIN.

SIGNAL: Green indicator lights when the channel pre-fade signal is greater than -12dBu.

FADER: Controls channel level feeding the main LR mix and post-fade aux sends. Also affects direct output if set to post-fade. Provides +10dB boost above its unity gain 0dB position.

The STEREO Effects Channel

The MixWizard features a built-in stereo digital effects processor. The processed signal is routed back to the mix through the ST1 (ST5) stereo return channel. The two stereo effects mix into the return channel. The ST1 (ST5) TRS jack inputs mix with the internal effects processor return, allowing internal and external effects devices to return their processed signals through one channel.

AUX SENDS: Combined effects signal can be returned to Auxes 1 to 4. These sends are not affected by the ST1 (ST5) LEV control. The stereo signal is summed to feed auxes in mono. This can be reconfigured via internal jumper options so that L feeds auxes 1,3 and R feeds auxes 2,4. Use aux sends to add effects to monitors.

Selecting the effect: Use the soft touch effects wheel to scroll through 20 effects. Press and release the wheel to toggle between effects channels on Aux 5 and Aux 6. Effect names and adjustable parameters are printed on the front panel.

Changing effects parameters: Hold the tap button and turn the effects wheel (value P0 to 9) to edit preset parameters. The parameter for each effect is listed below its name in square brackets.

Tap effects: Effects with a tap parameter show a flashing decimal point. Tapping the button changes the tempo. Tap effects are marked with [tap] on the effects list.

Turning off internal effects: Scrolling through all 20 effects displays a line indicating the effects are switched off.

Dual Effects Crossfeed: Effects channels can be combined to feed each other. Aux 5 effects can feed Aux 6 effects by holding the tap button and effects wheel while turning the wheel to select the mix amount (L0 to 9). The left decimal point indicates this feature is active. The AUX5 channel pot controls this dual effect, sending it through both AUX5 and AUX6 processors. The AUX6 channel pot controls the amount sent to only the AUX6 processor.

ST1 (ST5) LEV: Returns combined stereo effects to the main LR mix. Adjust from fully off to +6dB boost. Normal 3 o'clock 0dB position is marked.

FX MUTE: Mutes the stereo return channel, turning off the effects feed to the LR mix and auxes 1-4. Can also be muted using a footswitch. The red indicator lights when muted. The MUTE switch is latching.

Resetting effects presets: Hold the TAP key and effects wheel while powering up the console (with amplifiers off). The display will flash scrolling lines to confirm the reset.

The Master Section

AUX MASTERS: Each aux mix has a master level control to match output level to external equipment or trim monitor/effect sends without affecting the mix balance. Up to +4dB boost is available above the normal 0dB position. AUX5 and AUX6 master controls do not affect the internal effects processor level but do affect the rear panel aux output sockets.

LR FADER MASTERS: Individual faders adjust the main L-R mix level, providing +10dB boost above the nominal '0' position. For best performance, operate faders around '0' for normal loud level. If operating significantly below '0', the amplifier or destination equipment may be too sensitive for the console's +4dBu output. Turn down the amplifier/equipment level trim. If unavailable, use an attenuator pad. Operating faders well below '0' may degrade noise performance.

M FADER MASTER: A recessed mode switch above the M fader selects the fader source.

• Mono master: Use the M output as an L+R summed mono feed. The fader controls the master level for a mono PA, mono fill or delay speaker, additional zone, or mono recording.
• Aux master: Use the M output as the AUX6 master by pressing the switch with a pen or pointed object. Use post-fade AUX6 channel sends to mix required signals to the M output. This provides a main console output with its own mix bus. Typical applications include:
  • Dedicated MONO mix: For centre mono fill speakers (e.g., in theatres). Feed specific sources like radio mic channels for clarity. Aux sends create the required mix balance and master fader control.
  • Aux fed subs: Drives sub bass speakers with their own mix, sending only wanted low-frequency information. This cleans up the mix by keeping non-bass channels out of the subs, preventing low-frequency pickup from muddying the mix. Typically includes kick drum, bass guitar, keyboards, and sound effects. The master control for the sub mix is on a fader next to the main LR faders, allowing house volume control without upsetting the LR/sub balance. The feed to the sub speaker system is on balanced XLR and can be monitored by selecting the M switch in the headphones monitor section.

Console Monitor and AB Output

ST2 (ST6) RETURN

A simple stereo return channel routing to the main LR mix. Typical use is for CD or playback devices for walk-in or background music, or as an additional effects return. Adjust volume with the LEV control. Route to LR by pressing the TO LR switch; a green LED warns the source is routed to LR.

Use the ST2 (ST6) input to monitor your 2-track recording. Press the ST2 (ST6) monitor source select switch. Use the AB output to feed your recorder. When monitoring live, avoid accidentally pressing the TO LR switch, which would route your recording to the house speakers.

Console Monitor

Comprehensive engineer's headphones monitoring is provided. Select the source using the monitor switch bank. With no switch pressed, the post-fade LR mix is monitored. Press M to listen to the post-fade M source. Switches higher up the bank override previous selections. Pressing ST1 (ST5) listens to wet effects only return if the internal effects processor is active. Pressing Aux pairs (1-2, 3-4, 5-6) listens to the two selected auxes as a stereo pair. Console meters display the selected monitor source signal level.

Pressing channel PFL automatically overrides the current monitor selection with the pre-fade signal from that channel or selection of channels. The red PFL active indicator lights, and console meters display the channel signal.

Recommendation: Use closed-ear headphones (30-600 ohms) for live sound monitoring. Around 100 ohms impedance is popular.

WARNING: To avoid hearing damage, do not operate close-to-ear monitoring (headphones) for long periods at high volume. Continued exposure to high volume sound can cause frequency-selective or wide-range hearing loss.

AB OUTPUT

An additional stereo output configurable as a separately controlled mix output or a local loudspeaker monitor send. A recessed mode switch above the AB level control selects the source. Adjust output level from fully off to +10dB boost (normal 0dB position marked).

• Mode switch up (LR mix): Source is the LR mix. Factory default is post-LR fader. Can be changed to pre-LR fader via internal jumpers. Provides an additional main mix output ideal for independent fill speaker control, 2-track recording, or broadcast feed.
• Mode switch pressed (Monitor system): Source is the console monitor system. Use to feed local monitor speakers to listen to the source selected on the monitor switch bank, interrupted by PFL. Useful for theatre and stage monitoring applications.

Gain Structure

Gain structure refers to how levels are set between signal stages. For best performance, source signals must match the console's 'normal operating level', and connected amplifiers/destination equipment must match console outputs. Setting levels too high causes clipping and distortion; too low degrades signal-to-noise performance, resulting in hiss.

Using the Meters

The MixWizard provides input and output metering. For best results, operate the console with main meters averaging around '0', allowing loudest moments to reach '+6'. Reduce channel gain if red peak indicators flash. Peak indicators light 5dB before clipping. LED bar meters use a 'quasi-peak' response with fast attack and slow release for accurate transient display.

Matching a Source to the Console

Start by turning down channel faders and send levels to prevent unexpected loud volumes. Using PFL, adjust the GAIN control for an average '0' reading on console meters (which switch to show channel pre-fade signal when PFL is pressed). Listen via headphones or local AB monitor. Once gain is set, raise levels to bring the channel into the mix. Adjust gain if EQ changes significantly. Ensure inserted equipment operates around 0dBu line level. Set gain with inserted processors bypassed.

Matching the Console to Destination Equipment

The console produces a standard XLR output level of +4dBu for a meter reading of '0', with a maximum of +26dBu, providing ample headroom. If connecting to a sensitive power amplifier, turn down its input trim control if the normal console level is too high. Turning down console output faders degrades output stage noise performance and fader resolution. Output faders are best operated around '-10' to '0' for loudest average volume, allowing headroom.

Terminology

Normal operating level: Optimum signal level for best console performance, indicated by '0' meter readings, resulting in +4dBu XLR output. Channels operate at 0dBu, mix stages at -2dBu for headroom.

Headroom: Extra level above normal for loud peaks before clipping.

Signal-to-noise ratio (SNR): Difference in dB between normal level and residual noise floor (hiss).

Dynamic range: Sum of headroom and SNR, representing the maximum signal range from quietest to loudest.

A little care with gain structure throughout the signal chain yields the best performance and most manageable control.

[Diagram illustrating signal levels: NORMAL OPERATING RANGE, HEADROOM, SIGNAL-TO-NOISE RATIO, DYNAMIC RANGE, CLIPPING, SIGNAL, NOISE]

Specifications

Performance

• Maximum output level: XLR +26dBu into 600 ohms max load; Jack +21dBu into 2k ohm max load.
• Internal headroom: Channels +21dB; Mix +23dB.
• Meters: 3-colour LED, quasi-peak response. 0VU = +4dBu at XLR output. Master meters: 12 segment (-30 to +16dB). Channel meters: 2 segment (-12, +16dB, 5dB before clip).
• Frequency response: 10Hz to 30kHz +/-0.5dB.
• THD+n at +10dBu 1kHz: Channel to mix out < 0.004%.
• Crosstalk at 1kHz: Fader shutoff >90dB; Channel mute >90dB; Inter channel >90dB.
• Noise, rms 22Hz to 22kHz: Mic EIN -127dB; Residual output noise < -95dBu (-99dB S/N); LR unity fader mix noise < -83dBu (-87dB S/N).
• Channel HPF: 12dB/octave below 80Hz.
• Mono EQ: HF Shelving, +/-15dB, 12kHz; HM Peak/dip, +/-15dB, 500Hz to 15kHz, Q=1.8; LM Peak/dip, +/-15dB, 35Hz to 1kHz, Q=1.8; LF Shelving, +/-15dB, 80Hz.
• Stereo EQ: HF Shelving, +/-15dB, 12kHz; HM Peak/dip, +/-15dB, 2.5kHz, Q=1.8; LM Peak/dip, +/-15dB, 250Hz, Q=1.8; LF Shelving, +/-15dB, 80Hz.

Power Supply

• 100-240V, 50/60Hz auto sensing, IEC input.
• Power consumption: 45W max.
• Mains fuse: T630mA L 20mm.

Mechanical

• Free standing dimensions: W 507 (20") x D 530 (20.9") x H 194 (7.7").
• Rack mounted Underside connectors: W 483 (19") x D 122 (4.8") x H 444 (17.5") 10U.
• Rack mounted Rear connectors: W 483 (19") x D 193 (7.6") x H 497 (19.6") 11.2U.
• Weight: W4-122 unpacked 11kg (24lbs); W4-122 packed 14kg (31lbs); W4-162 unpacked 13kg (28lbs); W4-162 packed 16kg (35lbs).

Connections

MixWizard 4 Series Part Numbers:

• WZ4 12:2: 8 mic/line, 2 dual stereo, LR console (W4-122)
• WZ4 16:2: 16 mic/line LR console (W4-162)
• WZ4 14:4:2: 10 mic/line, 2 dual stereo, 4 group console (W4-1442)
• WZ4 12:2, WZ4 16:2 & WZ4 14:4:2 USB2 option kit (004-232JIT)
• SSM2142P balanced output driver option IC (AE0302)
• DRV134 balanced output driver option IC (alternative to above) (AE5725)
• Allen & Heath 18" gooseneck LED lamp (LEDLAMP)

WZ4 16:2 Block Diagram

[Detailed description of the WZ4 16:2 block diagram, illustrating signal flow from inputs through EQ, sends, faders, to outputs, including phantom power, effects, monitoring, and options.]

WZ4 12:2 Block Diagram

[Detailed description of the WZ4 12:2 block diagram, illustrating signal flow from inputs through EQ, sends, faders, to outputs, including phantom power, effects, monitoring, and options.]

User Options

The MixWizard offers versatile architecture, but internal options provide alternative settings for specific applications. Access to internal assemblies requires removing the base. Pluggable jumper links are used in most places; some links require cutting and soldering a solder bridge.

Remove the Base

Start by removing side trims using a Pozi crosshead screwdriver. Release the two M4 Pozi head pod securing screws and rotate the connector pod to access the three M3 rear base fixing screws. Use a Torx starhead screwdriver to remove these. Rotate the pod again to remove the four M3 underside base screws using the Torx driver. Carefully lift off the base.

Configure the Internal Options

• Jumper Options: Fit required options by setting jumpers to the correct positions. Ensure they are fully home. Check all channels are correctly set and all options fitted according to instructions. Ensure no debris or parts are left loose inside.
• Solder Options: Solder options require soldering iron skills. If reservations exist, contact a local service centre.

Refit the Base

Carefully reposition the base and refit fixing screws. Lock the connector pod in the required position using securing screws. Refit side trims if required.

IMPORTANT: Check that all channel options are correctly set. Errors may cause user problems later. It is recommended to write down repositioned option settings on a label and adhere it to the rear panel for reference.

[Diagrams showing locations for AUX PRE/POST FADER (solder option), AUX PRE/POST INSERT/EQ, DIRECT OUT PRE/POST FADER, AUX STEREO/MONO, AUX BALANCE OPTION, ST AUX STEREO/MONO, AB PRE/POST LR FADER options.]

Option Details

• MONO CH - AUX PRE/POST EQ: Factory default is pre-insert, pre-EQ. Change to post-insert, post-EQ by moving jumper from PR to PO. Auxes are always post-mute.
• MONO CH - DIRECT OUT: Factory default is pre-fader, common for live recording. Change to post-fade by moving jumper from PR to PO, suitable for direct channel effects sends.
• MONO CH - AUX PRE/POST FADER: Factory default is Aux 1-2 = pre-fade, Aux 3-4 = switched, Aux 5-6 = post-fade. Settings can be changed by cutting/resoldering links. Consider using AUX5 or 5/6 for internal effects (post) and/or AUX6 for aux-fed subs (post). Only change if necessary.
• STEREO CH - AUX PRE/POST FADER: Factory default is Aux 1&2 = pre-fade, Aux 3&4 = switched, Aux 5&6 = post-fade. Configure similarly to mono channels using jumpers.
• STEREO CH - MONO/STEREO AUXES: Stereo channels can feed auxes with a mono sum of L+R, or L feeds odd auxes, R feeds even auxes (preferred for stereo pairs). Factory default is mono. Ensure ST1 (ST5) stereo/mono jumper is set to the same position.
• AUX MASTER - ST1(5) MONO/STEREO: Configures ST1(5) AUX source.
• LR MASTER - AB SOURCE: Factory default is post-LR faders for AB output. Reposition jumpers to PRE to make AB output independent of LR master fader movements.
• Effects return stereo/mono aux source: Return channel ST1(5) feeds Auxes 1-4 with a mono sum. Can be reconfigured for stereo with L feeding Auxes 1, 3 and R feeding Auxes 2, 4.

AUX Master Balance Option & USB Option

AUX Master Balance Option

The 6 aux outputs are impedance-balanced (-2dBu nominal, +21dBu max drive), offering similar interference rejection to electronically balanced outputs. An electronically balanced option is available for nominal +4dBu and higher output drive (+26dBu) over long cable runs, though usually not necessary. Check if the option is truly needed before fitting.

Two balanced driver ICs (SSM2142 / AE0302 or DRV134 / AE5725) are suitable. To fit, snip the legs of two zero-ohm resistor links, solder the option IC into the socket, observing correct pin 1 orientation. Test output for correct level and opposite polarity signal between hot/ground and cold/ground.

NOTE: This procedure requires soldering. Contact Allen & Heath for assistance.

USB OPTION

A blanking plate covers the rear USB socket as standard. A USB multi-channel option card (004-232JIT) is available.

• This card sends 16 channels from the mixer to a computer for recording/processing. A stereo channel returns for monitoring or effects.
• WZ4 12:2: Sends Mono channels 1-8 direct out, Aux outputs 1-6, Left/right insert sends OR AB outputs.
• WZ4 16:2: Sends Mono channels 1-14 direct out, Mono channels 15 & 16 direct out OR AB outputs.
• The ST2(ST6) source can be toggled between the computer return feed or the input sockets.

Refer to WZ4 USB option application note AP8987 and fitting instructions AP8988 for full details.

Cue Sheet

This section provides blank pages for recording console settings for the WZ4 12:2 and WZ4 16:2 models.