Drawing upon the success of its predecessors in the UPMAX line, this compact, lightweight, and rugged unit produces stunning 5.1 channel audio from two-channel sources and is perfectly suited for OB trucks and post-production facilities.

Offering AES and auto-sensing HD/SD-SDI I/O, the UPMAX v4-D combines the renowned UPMAX® upmixing/downmixing algorithm with AutoMAX-II™ auto-detection for seamless transitions between stereo, three channel, and native surround input sources, producing an upmix that is completely downmix compatible.

The UPMAX v4-D comes standard with a built-in ITU loudness meter, dual power supplies, internal relay bypass, SNMP monitoring.


  • 5.1-channel audio from 2- and 3-channel sources 

  • Fulltime 2-channel downmix output

  • Very low latency for live applications

  • HD/SD-SDI and AES inputs

  • HD/SD-SDI, AES outputs

  • Built-in ITU loudness meter

  • SNMP monitoring

  • Dual redundant internal PSU and relay bypass


The Most Stable and Trusted Upmixing Available

Tracing its lineage back to the original UPMAX 2251, UPMAX v4-D offers the most stable and trusted algorithm in use today for both production and unattended upmixing. Critically, its output is completely downmix compatible and the resulting downmix is nearly indistinguishable from the original 2-channel source. For unattended operation, AutoMAX-II detection seamlessly and automatically transitions between discrete and upmixed audio, or control can be handled via GPI/O.


Flexible Surroundfield

The upmixed “surroundfield” can be infinitely adjusted, allowing programming ranging from simple stereo audio to an LtRt downmix to be appropriately reproduced through a 5.1-channel playback system. Optional bass enhancement for the LFE channel allows a subwoofer channel to be created without compromising the downmix.


Built-in Loudness Metering

A built-in LKFS meter provides loudness measurements per ITU-R BS.1770-3, simplifying the process of making sure output levels are properly adjusted to comply with loudness regulations around the world.




  • Linear Acoustic UPMAX with AutoMAX-II



  • 4.6 msec (SRC bypass), 7 msec (SRC On)



  • 48kHz, 24-bit; Signal levels per SMPTE 276M/AES-3ID-2001; All connectors are 75-Ohm BNC female with internal 75-Ohm termination



  • Auto-sensing and de-embedding of up to 16 channels from applied SDI signal with upmixing and/or re-embedding up to 16 channels. Signal levels per SMPTE 292M/259M. Supports (SMPTE) 2020 A and B VANC metadata. Up to 1080i/60/59.94/50Hz supported


Parallel GPI/O Control Port

  • 9-pin female D connector, 0-5v TTL levels


Serial/Metadata Input

  • 9-pin female D connector, 115 kbps, pinout per SMPTE 207M (RS-422/485)/RDD6


Front Panel Controls and Indicators

  • Rotary encoder and graphical OLED display


Power Requirements

  • Dual, redundant 100-264 VAC, 50/60Hz, auto-sensing, 35W maximum


Dimensions and Weight

  • 1RU - 1.75”H x 19”W x 11.5”D (44 x 483 x 317 mm)

  • Net weight: 6 lbs. (2.72 kg), approximate.


Shipping Dimensions and Weights

  • 22”W x 17”D x 7”H (178 x 559 x 432 mm)

  • Net weight: 13 lbs. (5.9 kg), approximate.



  • Convection cooled. Operating: 0 to 50 degrees C, non-operating –20 to 70 degrees C.



North America: FCC and CE tested and compliant, power supply is UL approved.

Europe: Complies with the European Union Directive 2002/95/EC on the restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS), as amended by Commission Decisions 2005/618/EC, 2005/717/ EC, 2005/747/EC (RoHS Directive), and WEEE.



Standard 2-year limited parts and labor