SX-R4+ frontSX-R4+ rightSX-R4+ leftSX-R4+ wifi interface


16 tracks recorder on dual SD card system


Product Description

Inputs / Outputs

  • 4x XLR-3F inputs, individually configurable as:
    – ANALOG: mic/line levels, electronally balanced, with phase reversal, 48V phantom, LF cut and level control on the front panel
    – DIGITAL: transformer balanced AES3 or AES42 with ASRC, phase reversal, LF cut and level control on the front panel$
  • 2x Line inputs, electronically balanced on TA-3 with level control on the front panel
  • 4x AES3 balanced inputs on multi-pin connector
  • 1x AES3 balanced input with ASRC on TA-3 connnector (shared with AES3 output)
  • 2x analog unbalanced line outputs on TA-3
  • 1x AES3 balanced output (user independant sampling frequency) on TA-3 connnector (shared with AES3 input)
  • Up to 12x Mic inputs when connected to the SONOSAX AD8+
  • Optional audio over IP on RJ45 connector, such as AVB, Dante & Ravenna


  • 135 dB (A-weighted) overall dynamic range from analog input to recorded file (114 dB (A-weighted) dynamic range with USA version)
  • 90kHz overall frequency response @192 kHz recording
  • 40 bits processing

Recording capabilities

  • up to 16 tracks recording on 2x SD cards (SDHC, SDXC)
  • uncompressed BWF with iXML metadata
  • 44,1 up to 192 kHz @ 24bits, Pull up/down 0.1% for NTSC world

User Interface

  • Touch screen 2.4” TFT color display
  • WiFi dynamic web-app interface


  • Removable 14.4V 48Wh Lithium battery, SMBUS capable
  • External DC 9..18V on Hirose 4pins, SMBUS capable, electrically isolated
  • 12V regulated decoupled DC output to power peripherals equipments up to 7W
  • Intelligent energy management with detailed on-screen information


  • Accuracy: 0.5 ppm
  • Independant in/out on lemo connector
  • 23.976, 24, 25, 29.97DF, 29.97ND, 30DF, 30ND


  • Machined aluminum housing
  • Overall dimension: 200 x 50 x 144.5 mm (7.87” x 1.96” x 5.7”)
  • Weight: 910g / 2.0lbs without battery, 1.2kg / 2.64lbs with 48Wh battery

User manual – Hardware description
User manual – Software v1.2 (see below for latest firmware documentation)

Latest firmware documentation
Front Panel
Audio Inputs
Audio Outputs
Menus Overview
Record Tracks menu
Take List menu
Setup menu
User Settings menu
Push Buttons menu
System menu
Sound Report

USA version – Audio pro and patents [EN]
Version USA – Audio pro et brevets [FR]



Firmware Update procedure

Version 2.5
November 2016


  • Added SX-AD8+ and SX-RC8+ operation from SX-R4+
  • Fixed timecode accuracy (was not accurate when cycling power with 23.976 and 30 fps). Also fixed some drift when switching from EXT JAM SYNC to the same frame rate.
  • Fixed SD card filename bug (same filename in a folder).
  • Fixed phase reversal input level issue: when using fader mude, a phase change using a push button assigned function can corrupt the input level
  • Fixed take number generation: wasn’t correct when scene changed during recording
  • Minor interface bugs fix

Version 2.4
July 2016


  • Modifying metadata of an existing take with the HTML web interface results in a bad filename of next take to be recorded
  • 23.976 & 30 fps timecode formats are not accurate after a power cycle

Version 2.4 is a fix for version 2.3, which has a major bug.

It is important to apply a full factory reset as described in the simplified update procedure to prevent running new firmware with an old configuration.


  • Fixed timecode bug (was not correct on SD2)
  • Fixed SD card ‘SPEED’ error
  • Fixed monitoring bug
  • Fixed take edition bug (metadata wasn’t saved properly)
  • Fixed alarm level (was active even when disabled)
  • Fixed take number generation (wasn’t correct if a take was shot with identical scene name)
  • Fixed sound report (false start takes were displayed and projects were not filtered)
  • Fixed system instability involving 4 channels output option card and sampling frequency changes
  • Fixed monitoring bug for 4 channels output option card (mix channels weren’t mapped)
  • Enhanced WiFi communication
  • Added WLAN channel selection for Access Point (AP) mode
  • Minor interface bug fix & enhancement

Version 2.2
May 2016


  • Added optional XLR5-M output card support
  • Fixed input level bug: when entering fader mode with pot closed, level was frozen to MUTE.
  • Fixed track menu bug: in some rare case, modifications were not saved
  • Fixed SD card ‘SPEED’ error

Version 2.1
March 2016

Official version jumps from 1.4 to 2.1; version 2.0 only exists as beta. If you’re running version 2.0, please update to version 2.1.


  • XLR inputs levels remain fixed to MUTE. In fader mode, the input level can be modified using the rotary encoder in the input menu. However, if the input level is MUTE, input level change does not work. Workaround: do not mute inputs before entering fader mode.
  • Record sometimes fails on a SD card with the ‘SPEED’ error on the card. More frequent with low track count (1-2) on high speed cards.


  • Fixed playback channels swap
  • Fixed playback timecode (wasn’t displayed)
  • Fixed timecode accuracy
  • Fixed 176.4/192k operation
  • Fixed record start: under some rare condition, record start could be ignored
  • Fixed power failure filetag: was identical to previous take
  • Fixed ambient light sensor calibration and auto dim mode
  • Added User Settings menu
  • Added timecode date in user bits
  • Added system time zone
  • Added fader operation mode
  • Added SD2 Mix Only recording
  • Added 24bits WAV file recording/playback
  • Added note field in Tag Last Take menu
  • Added track coloring
  • Added meter range user selection
  • Added sound report file generation
  • Improved monitor/mix menu: presets are now independent from each others
  • Improved audio performance and behavior
  • Improved various menus (Inputs, Monitoring/Mixing, filetag, push buttons, date/time, split Record Tracks menu into Rec Tracks and Mix menus)
  • Improved HTML5 web remote application
  • Minor bug fixes and interface adjustments

Version 1.4
November 2015

Version 1.4 is a fix for version 1.3, which has a major bug.


  • Sampling frequencies of 176.4k and 192k not yet supported
    WAV file creation time may be incorrect due to timezone
  • USER SETTINGS menu is not implemented
  • Modifying playback position can result in channel swap


  • Fixed file system (setting file to hidden was incorrectly implemented)

November 2015

Applying a false start will corrupt the file system, making some files unreadable. Please update to version 1.4.

Once updated, press AND HOLD REC button until boot screen appears to power up the SX-R4+.


  • Fixed monitor presets: wasn’t restored at boot time
  • Fixed take list menu: selected take timecode wasn’t correct
  • Fixed pop noise during playback start
  • Fixed AUX AES output: channel status is now in pro mode
  • Fixed various minor bugs
  • False start files are now hidden
  • Full re-work of the metadata menu: scene is 10 alpha-num chars, added tag last take, added user editable snipped list for track names and notes
    Full re-work of the push button assign menu (SETUP/SYSTEM/PUSH BUTTONS)
  • Added file size selection: fow now limited to 4GB (until WAV64 is implemented)
  • Added RECORD TRACKS menu
  • Added encoder long press new menu with various useful links and tools: timecode, track names, track arming, screen lock, headphones lock, display brightness, daylight mode
  • Added timecode set manual
  • Added quick power-down (to be enabled in menu SETUP/SYSTEM/POWER DOWN SETUP): press and hold REC button in rec ready to power down unit.
  • Added solo in headphones menu
  • Added a second reference level: user can now configure ‘orange’ level and ‘red’ level
  • Added a config save button (SETUP/SYSTEM) to force configuration save (done at power down)
  • Player: loading a take no longer begins automatically playback; encoder can be used to modify playback position (1 step = 1%), to change headphones level, enter pause or stop states.
  • Various minor interface improvements