$795.00 per ea

Quantity Price
ea $795.00
2+ $720.00
per ea
All prices shown are (inc. GST)


This unique Redback PA mixer features four input channels which are user selectable for either balanced mic, line or auxiliary use. In addition it incorporates a four channel SD card based message player making it an excellent choice for retail, supermarkets, hardware stores and more. The mixer could be used for general paging and BGM applications, and the message player for customer service applications, in-store advertising or for pre-recorded commentary at galleries, display stands etc.

The message player and each input all have individual level, treble and bass controls. Vox muting is provided for channels one and two with front panel adjustable sensitivity. The message player has priority and slots in between input one and two. Custom messages, tones and music may be loaded onto the message player SD card. The messages are activated by a closing set of contacts. If input one is active when a message contact is closed, the message is queued and played once input one is no longer in use.

Messages are played on a first in, best dressed (FIBD) basis, and will also be queued if one message is playing and another is activated. Input four is also fitted with a 3.5mm jack input for connection to a smartphone/tablet as an audio source. When connected, this overrides any source connected to input 4 on the rear panel. Each input has a 3 pin XLR (2mV) and stereo RCA socket with adjustable sensitivity settings. These can be set 100mV or 1V for the stereo RCAs. Message player contacts are provided via pluggable screw terminals. 24V DC operation from the included power supply or battery backup.

Package Contains:
A 4427 Mixer 4 Channel with MP3 Message player
24V 1A DC Plugpack
Instruction Booklet


  • Six Mic (Dinkle connectors) / Line (Dual RCA) Input channels (Inputs 1-6)
  • Two dedicated RCA Line Input channels (Inputs 7-8)
  • PTT Input and 24V PTT output (limited to 120mA) on inputs 1-6
  • Micro SD card based Alert/Evac/Chime/Voice-over module (In built)
  • Individual level, bass and treble control on all inputs • 3.5mm music input overrides input 8
  • Three levels of priority
  • Adjustable Vox sensitivity on inputs 1-6
  • Adjustable input sensitivity 1V/100mV on inputs 1-8
  • Phantom Power on inputs 1-6
  • Tape out (Dual RCA)
  • Balanced Output (XLR male)
  • Five sets of closing contacts for message triggering (Alert/Evac/Ch1/Ch2/Cancel)
  • 24V DC switched output (Limited to 120mA)
  • MP3 active indicator
  • Signal Present indicator
  • LED VU Meter
  • 24V DC operation (Plugpack Supplied)
  • 24V DC battery back up terminals
  • 10 Year Warranty
  • Australian Designed and Manufactured

100% developed, designed & assembled in Australia.
Since 1976 Redback PA products have been manufactured in Perth, Western Australia by Altronics. With over 40 years experience in the commercial audio industry, we offer consultants, installers and end users reliable products of high build quality with local product support. Read more about our Australian Made products

Backed by an industry leading 10 Year Manufacturer Warranty.
Our Redback products have a long tried and tested history of bulletproof reliability. Altronics offers a 10 Year Warranty on all Australian Made Redback products. Our local in-house service department has all the know how to answer technical queries and provide timely service. Read more about our industry leading warranty.

Information & Downloads


  • Output Level: 0dBm
  • Distortion: 0.01%
  • Frequency Response: 140Hz - 20kHz
  • Sensitivity: Mic inputs: 3mV balanced
  • Line inputs: 100mV-1V
  • Output Connectors: Line out: 3 pin XLR balanced or 2 x RCA
  • Switched out: Screw terminals
  • Input Connectors: Inputs: 3 pin XLR balanced or 2 x RCA 3.5mm stereo jack front panel
  • 24V DC power: Screw terminals
  • 24V DC Power: 2.1mm DC Jack
  • Remote triggers: Screw Terminals
  • Controls: Power: Standby Switch
  • Bass: ±10dB @ 100Hz
  • Treble: ±10dB @ 10kHz
  • Master: Volume
  • Inputs 1-4: Volume
  • MP3: Volume
  • Indicators: Power on, MP3 error, Message active
  • Power Supply: 24V DC
  • Dimensions: 482W x 175D x 44H
  • Weight: 2.1kg
    • *Specifications are subject to change without notice.

Warranty & Returns


We offer 10 years warranty on this product from its date of purchase. This is available from Altronics stores, online purchases or Altronics resellers. In accordance with our full warranty terms we will repair, replace or refund if goods you have purchased from us are defective.


Not withstanding our warranty policy, if you are dissatisfied with our goods or service you may return the goods within 14 days of our despatch date. Simply contact us for a return authorisation number and we will refund your purchase in full, less transport costs on receipt of goods. All returned goods must be in as sold condition including all packaging, instructions, invoices etc.