SOUND4 FIRST provides all the most important functionalities you need in an FM/HD processor and sets the bar high both in terms of performance and affordability. Designed to deliver a sound of uncompromising quality, this tool gives you 2-band processing, a digital stereo generator and an IMPACT Clipper.

One of the most important advantages of this product is the fact that audio airs just three seconds after powering on the device. This tool is fully BS-412 compliant and comes with an HD Limiter, a Low Distortion Bass Clipper and a Low Distortion FM Limiter. SOUND4 FIRST has Analog, Digital and AES-67/Livewire inputs and outputs, as well as an MPX FM output. It also solves the so-called “blending problem” resulting from the switch of receivers from stereo to mono, bringing you a constant level of clear audio.

The impressive backup functionalities ensure a reliable, uninterrupted audio feed. SOUND4 FIRST provides a streaming output fully compatible with all standard servers, including HLS.

Software Options Available *

There are a number of options and additional features that make the SOUND4 FIRST even more valuable. These include Basic and Full RDS, Streaming Extension, IP TX + RX and Dual IP TX + RX to name but a few. A full list of all software options is available below:

  • Basic RDS Encoder
  • Full RDS Encoder
  • Streaming Extension
  • IP Tx
  • IP Tx2
  • IP Rx
  • IP Rx2
  • IP RX + Tx
  • Dual IP Tx + RX
  • IP Pass Through
  • Emergency URL Player
  • Emergency Audio Player

* All Software Options are subject to an additional payment. For pricing please Contact Us.

SOUND4 FIRST has a compact 1U case and a dual power supply which is a standard feature of all SOUND4 In-box products and ensures uninterrupted operation of the unit, as well as a user-friendly remote control interface to provide clients with easy setup - a clever choice for your station.


  • Dual Power supply
  • 2 Processing path: FM & HD
  • Inputs: 2 AES/EBU 32 to 192 kHz, 2 analog, 2 AES-67/Livewire or 2 IP Codec (SOUND4 IP CONNECT), 2 SUB (insert for RDS/RBDS...)
  • Outputs: 2 AES/EBU 32 to 192 kHz, 2 analog, 2 AES-67/Livewire or 2 IP Codec (SOUND4 IP CONNECT), 2 MPX
  • Digital AES/EBU and wordclock synchronization inputs.
  • 3 independent Ethernet ports: Admin, AES-67, IP-CONNECT
  • GPIO: 8 inputs, 8 outputs, advanced management with scripts
  • GPS Sync for System time and AoIP Sync
  • Micro SD: High capacity management, SDXC compatible standard (up to 2TB), for music storage and more
  • Two USB ports: front and rear (for preset & upgrade loading and other functionalities)
  • Headphone output on front panel with the possibility to listen each Input or Output
  • Full Routing management: Patch points with Insert and Mix on all stages, routing of signals to any Inputs and Outputs
  • Automatic failover input switching with crossfade
  • Diversity Delay: up to 20 seconds
  • Relay switch for automatic by-pass
  • Fully controllable from front Panel
  • GUI remote control compatible 32 & 64 bits - Windows 7, Windows 8 & 8.1, Windows 10, Windows 11, 2008 R2, 2012 and Linux (Debian)
  • HTML5 GUI: Inputs and outputs setup, preset change, upgrades...
  • Start-up time of SOUND4 FIRST: 2 seconds to be on air (Analog Input or AES/EBU input)
  • Total DSPs computing power for audio Processing: 16,2 Giga Flops (Sharc 40 bits with floating point + other DSPs)
  • Total ARMs computing power for product management and extra functions: 4 GMips


User-Friendly Control Interface

  • Sound setting from one single screen - you no longer need to open and close windows to go from one function to another
  • Two modes - Basic and Advanced. Basic mode provides simplicity and rapidity; Advanced mode allows you to explore all the processor functionalities. There are also ultra-rapid VU meters for true control over modulation
  • Advanced meterings with FFT and MPX Power
  • Unlimited “Undo/Redo” versioning function for presets with possibility of recall
  • Innovative “compare to reference” function
  • Log comment feature follow each preset
  • A readable and interactive path diagram
  • A remote connection manager to control several processors
  • Works with the following operating systems - WXP SP3, W7 32& 64 bits, W8 32 & 64 bits, WS 2008 R2, WS 2012, Linux (Debian)



  • HQ Sound, main sampling process frequency of 192 kHz.
  • 2-band AGC
  • 2-band limiter
  • 4-band EQ
  • Final limiters:
    • FM path - Bass Clipper + FM Limiter + MPX Limiter
    • HD path - Look Ahead limiter for the HD output
  • Voice Smoother to avoid distortion problems on certain voices
  • BS412 compliant MPX power controller
  • Typical processing delay at 1 KHz:
    • HD output: 3 to 6 ms
    • FM output: 18.5 ms
    • MPX output: 25 ms


Other key points:

  • 19 kHz embedded pilot to gain close to 1 dB more in loudness!
  • Auto-Mono: Switch off pilot 19 KHz on mono sources for better receiving in FM
  • Stereo Matrixing for better stability in loudness and sound tone when the receiver switches from mono/stereo/mono
  • Adjustable Filters Frequencies in 2-band AGC and 2-Band Limiter



  • Basic RDS encoder (with scrolling PS)
  • Full RDS (UECP-compatible)
  • IP Codec - SOUND4 IP CONNET (manage up to 32 Links!)
  • Emergency Player: Audio program backup, 2 music libraries, 1 Jingle Library + rules management
  • Audio streaming - 3 encoders (MP3, AAC, HE-AAC v1 & v2), compatible with all delivery servers (Icecast, Shoutcast v1 & V2, HLS, Flash, Wowza)
  • Link & Share - 100% of all parameters are accessible via the telnet protocol
  • Software Panels - the device allows you to create your own panels with unlimited functionality
  • Preset Sharing - the ultimate solution to manage an unlimited number of processors. All of them are automatically updated if one of them is modified


  • Analog Input
    Quantity2 stereo
    Level2 ranges (+12 or +24 dBu - software selectable)
    Impedance10 kΩ
    Connectors1 pair of XLR female balanced, EMI suppressed;
    1 pair on a DB25 female (TASCAM pinout) balanced, EMI suppressed
  • Digital Input
    Quantity2 stereo
    Sampling Rate32 to 192kHz, 24 bits
    Connectors1x XLR female balanced , EMI suppressed;
    1 on a DB25 female (TASCAM pinout) balanced, EMI suppressed
  • AES/EBU Input Sync
    Quantity/Connector1 on a DB25, EMI suppressed
    Sync TypeWord Clock - 32 to 192 kHz
    VideoPAL or NTSC
    Level1 to 6 Volts
    Impedance75 Ω
  • SCA/RDS Input
    Quantity/Connector2x BNC, EMI suppressed
    LevelSame as MPX output (adder)
    Impedance75 Ω or 10 kΩ, jumper selectable
  • Analog Output
    Quantity2 stereo balanced (with automatic unbalancing)
    Level2 ranges (+12 or + 24 dBu - software selectable)
    Load Impedance10 kΩ typ. (> 300 Ω)
    Connectors1 pair of XLR male balanced, EMI suppressed;
    1 pair on a DB25 female (TASCAM pinout) balanced, EMI suppressed
  • Digital Output
    Quantity2 stereo
    Sampling Rate32 to 192kHz, 24 bits
    Connectors1x XLR male balanced, EMI suppressed;
    1 on a DB25 female (TASCAM pinout) balanced, EMI suppressed
  • Stereo Generator MPX Output
    Quantity/Connector2x independent BNC, EMI suppressed
    SignalMPX or 19kHz pilot
    Level2 ranges (+6 or +18dBu - software selectable)
    Load Impedance75 Ω typ. (> 35 Ω)
  • Audio Specifications
    Processing Delay MPX30ms
    Processing Delay Analog Out (HD)11ms
    Frequency Response MPX30Hz - 15 kHz +/-0.2dB (de-emphasized)
    Frequency Response Analog Out (HD)20Hz - 15 kHz +/-0.1dB (de-emphasized)
    Signal to Noise>90 dB
    Distortion MPX<0.018% THD
    Distortion Analog<0.006% THD
    Separation>70 dB
  • Audio Over IP
    Live Protocol (AES67)Ethernet 100Mbps;
    Compatible AES67, Ravenna, Livewire;
    48kHz, 24 bits, stereo, >= 12 samples/packet (250µs), delay 1ms
    Transport protocol (IP)Ethernet 100Mbps;
    High quality stereo codec (32 to 200kbps) or linear;
    2.5s compensation buffer
  • Power Supply
    TypeDual Redundant
    Voltage100 – 260 Volt AC, < 40W
  • Operating conditions
    Operational between0 – 50°C
  • Size and Weight
    Dimensions (WxHxD)485 x 44 x 260 mm
    Shipping Weight550 x 120 x 580 mm / 3.900 kg
    HS Code8517620000
  • Power up boot
    Boot time3s
  • Bypass relay
    AESAES in => AES out
    AnalogAnalog in => Analog out
  • Optional interfaces
    USB2.0, for upgrades
    micro SD cardfor music files
    RS232DB25 standard, for RDS (shared with GPIO)
    GPS inputFor System time and AoIP Sync. SMA connector (active antenna)
    GPIO8 inputs, 8 outputs (opto-isolated) with 5V supply (DB25 male)
  • SOUND4 REMOTE CONTROL Software Operating Systems
    Linux Debian32 & 64 bits
    Microsoft Windows32 & 64 bits: Windows 7, Windows 8, Windows 10, Windows 11, Windows Server 2008 R2, Windows Server 2012, Windows Server 2016, Windows Server 2019
  • PC to Client Communication Interface
    TCP/IPClient (Remote) / Server (Impact) architecture via Ethernet 1000Mbps
    Link & ShareAll parameters are accessible via simple Telnet protocol
    SNMPSupervision with Trap Feature
  • Quick User Guide

    SOUND4 IMPACT/PULSE/FIRST Quick User Guide (English)
    Size: 1.22 MB Download

    SOUND4 IMPACT/PULSE/FIRST Quick User Guide (Russian)
    Size: 1.24 MB Download

  • User Manual

    SOUND4 FIRST User Manual (English)
    Size: 16.96 MB Download

    SOUND4 FIRST User Manual (Spanish)
    Size: 16.92 MB Download

  • Software

    Universal All Products Installer

    The Universal Products Installer is the complete installation kit for all SOUND4 Products. Whatever you are using, an In-Box (19 inch racks) or a In-Card (PCIe or PCI cards), the Universal Products Installer installs the software suite for HD/FM products, IP Codecs, Voice Processors and Streaming Processors...

    The Universal Products Installer includes:
    • The Remote Control Software for In-Box and In-Card Products
    • For In-Card Products (PCI & PCIe):
      • SOUND4 cards Drivers (PCI & PCIe)
      • The SOUND4 Server (the service which handles data communication from/to cards)
      • Latest upgrade files (for all PCIe & PCI products)

    Link&Share Transmitter

    Link&Share is an open command protocol compatible with all SOUND4 Products. Thanks to Link&Share, it is possible to change a product Input, change the On Air Preset, switch an IP Link... Everything is possible with Link&Share!

    Here is the Link&Share Transmitter which offers you the possibility to send commands by script...

    Remote Support Tool
    Size: 4.25 MB Download

    You need a dedicated support, you need our assistance remotely on your equipment... No problem, the TeamViewer Remote Tool Support is at your disposal.

    When downloaded, run it directly. In the window, you will see an ID number and a password. Please send it to our support team for a dedicated remote support.

    Note: this third party tool is provided for free.

  • Images


    This archive contains all images from product's gallery.

SOUND4 FIRST is offering as an option the Kantar Media Audio Watermarking Technology for audience rating. Today, depending on the country, radio stations can be listened to on FM, DAB or Streaming, and polling companies need to know the audience results for each of the media.

In the SOUND4 FIRST, watermarking is always carried out at the end of the processing chain to guarantee maximum watermarking quality.

The SOUND4 FIRST is the most advanced watermarking processor and can tag up to 3 different feeds:

  • 1 for the HD/FM output
  • 1 for the 1st streaming encoder
  • 1 for the 2nd streaming encoder


About Kantar Media watermarking technology:

SNAP audio watermarking technology by Kantar has been designed for TV and Radio audience measurement. In addition, it can also be used for the synchronization of a second screen application. SNAP watermarking carries 2 types of information, a channel identifier and a timestamp for linear content and a timecode for non-linear content.

The audio watermarking technology can be described by 3 main properties: the inaudibility of the watermarking, the amount of data carried by the watermarking and the robustness of the watermarking.

The SNAP technology remains inaudible thanks to a very complex acoustic model and preserves the quality of the sound. This is a crucial property for TV channels and Radio stations that invest time and money into getting the best quality for their sound. Regarding the amount of data, the SNAP technology proposes a single payload for Channel and Content identification. The robustness of SNAP watermarking in the broadcast chain is also a key element. SNAP is robust to low encoding bitrates, and to adaptive bitrates. Don’t hesitate to contact Kantar support to get bitrate recommendations depending on the audio codec.