Specialist suppliers of pro audio/video equipment to the film,
post-production, broadcast and music recording industries.

Bel Digital Audio BM-A1-2SHD MKII 2 Channel Audio Monitor

High-quality 2 channel SDI monitoring unit

The Bel BM-A1-2SHD MKII is a high quality, 1U, 2-channel audio monitor/de-embedder suitable for operation in broadcast control rooms or OB vehicles where SDI is the standard video format. It is able to de-embed audio from any pair of channels from 3G/HD/SD SDI, and display the levels on the front panel meters, and to provide stereo audio monitoring.

Condition: new

in stock
£2,484.00 £2,070.00 ex VAT
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£2,484.00 £2,070.00 ex VAT

Bel Digital Audio

Product Description


The unit is very simple to use: all source selection and main monitoring setup is done from individual controls on the front panel without any necessity for menu navigation.

In addition to two auto-detecting 3G/HD/SD SDI inputs, a re-clocked loop-through output is available for the selected SDI source providing a convenient and cost-effective method of switching SDI feeds to an external monitor. The stereo audio monitor mix is also available as a separate balanced feed at a pair of XLRs.

Audio levels are metered on two 26-segment tricolour LED bargraphs. User setup options allow a choice of four scales and ballistics (including BBC or DIN PPM, VU and AES/EBU), and also colour transition points and peak hold.

The audio quality is remarkably high for a 1U unit in addition to the front panel stereo speakers a third low frequency driver is mounted internally to provide an impressively extended low frequency response for such a compact monitor unit. Users have full flexibility in assigning either channel to left, right or both speakers (or neither), and automatic level attenuation compensates for monitoring multiple channels. A ¼” jack headphone output socket is provided on the front panel. When in use, the internal speakers are muted. Audio level at the rear panel analogue outputs may be configured from a setup menu either to be fixed or to follow the main volume control.

The BM-A1-2SHD MKII is fitted with a display screen, enabling easy device configuration and display of signal status information.

The unit, built to a very high mechanical standard in a stainless steel 1U 19” enclosure, is designed to give the best possible isolation from external interference and vice versa, and is fully RoHS compliant.


  • Metering and monitoring of 2 channels of audio   
  • 2-channel audio de-embedding from SDI sources, selectable in pairs
  • 2 auto-sensing SDI inputs (SD/HD/3G)   
  • Very simple to use: all primary functions have individual controls   
  • Display for input status and unit configuration   
  • 2 x full-range front panel speakers plus internal LF sub-woofer   
  • Either channel may be monitored on either speaker, including combinations and groups
  • High resolution, tricolour LED meters with adjustable colour transition points and peak-hold facility
  • Four standard meter scales/ballistics, user selectable
  • Audio output levels are auto-adjusted for consistent volume when monitoring multiple channels
  • 200 mm depth chassis: ideal for OB applications


Additional Information


Video Inputs

  • Input: 2 x 3G/HD/SD SMPTE 424M, 259M, 296M, 274M, 292M
  • Output: 1 x SDI loopthrough



  • Bargraphs: 2 x 26 element tricolour with adjustable colour break points


Analogue Monitor Outputs:  2 x XLR3M

  • Max output level: +15 dB
  • Noise + THD: -98 dB


Digital Channel Outputs x 8: 4 x 75 ohm BNC

  • Digital AES-3id


Frequency response

  • All analogue outputs: 20 Hz to 20 kHz ±1 dB


Main drive amp

  • Noise + THD: -80 dB w.r.t. maximum output


Speaker driver units

  • Peak acoustic level (@2ft): 100 dB SPL
  • Shielding: Magnetic


Scales and Ballistics

  • DIN PPM: Overall dynamic range: 55 dB (+5 to -50 dB) Attack time: 10 mSec Fallback: 1.5 Sec per 20 dB decay
  • BBC PPM: Overall dynamic range: (+12 to -12 dB from mark 7 to mark 1) Attack time: 10 mSec Fallback: 2.85 Sec (from mark 7 to mark 1)
  • VU: Overall dynamic range 23 dB (+3 dB to -20 dB) Attack time: 300 mSec Fallback: 300 mSec
  • AES/EBU: Overall dynamic range 60 dB (0 to -60 dB) Attack time: 1 mSec Fallback: 1.5 Sec per 20 dB decay



  • 19” Rack Mount: 1U high.
  • Outline Dimensions: 483 mm(W) x 200 mm(D) x 44.5 mm(H) Outline Dimensions: 19 inch(W) x 10 inch(D) x 1.7 inch(H)


  • 90 - 264 VAC 50/60 Hz Autoselect, Fuse 4A HAC


  • Temperature 0 °C to 30 °C. Humidity 70% max (non-condensing)



  • 4 kg (9lbs)