BEL BM-A1-16SHD User manual

BM#A1#16SHD*
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Manual
BM-A1-16SHD
16 Channel Digital Audio Monitor

BM#A1#16SHD*
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User’s Guide
Version 2.0 18/12/2012

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BEL (Digital Audio) Ltd., has made every effort to ensure the accuracy of information contained within
this document, which is nevertheless supplied for information purposes only and does not constitute any
form of warranty or guarantee.
All trademarks acknowledged.
The information in this document is subject to change without notice.
Bel (Digital Audio) Ltd.
Unit 3
Horwood Court
Bletchley
Milton Keynes
Bucks
MK1 1RD
United Kingdom
Tel: [phone]
Email: [e-mail]
Web: www.beldigital.com

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Contents!
Contents'..................................................................................................................................................'4'
Introduction'............................................................................................................................................'5'
Main'features'..........................................................................................................................................'6'
Front'panel'rotary'controls'.....................................................................................................................'7'
Operation'................................................................................................................................................'8'
Selecting'sources'.................................................................................................................................'8'
SDI'input'mode'...................................................................................................................................'8'
Dolby'mode'.........................................................................................................................................'8'
Using'the'PROGRAM'switch'................................................................................................................'8'
Directing'sources'to'speakers'.............................................................................................................'8'
Status'display'..........................................................................................................................................'8'
Rear'panel'inputs'....................................................................................................................................'9'
Rear'panel'outputs'..................................................................................................................................'9'
Menu'.....................................................................................................................................................'10'
Top'level'menu'page'.........................................................................................................................'10'
Level'Meter'Adjustment'...................................................................................................................'11'
Line'level'output'adjustment'............................................................................................................'12'
Analogue'output'level'.......................................................................................................................'13'
Dolby'Information'.............................................................................................................................'13'
Installation'............................................................................................................................................'14'
Analogue'audio'inputs'and'outputs'..................................................................................................'15'
Specifications'........................................................................................................................................'16'
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Introduction!
!!
The BM-A1-16SHD is a 1U high-quality sixteen-channel video/audio monitor with multiple I/O
as standard. The unit accepts audio from any one of four AES input pairs, eight analogue
inputs or one of two SDI inputs and produces four pairs of AES outputs and eight analogue
outputs. The SDI inputs automatically detect SD or HD or 3G video and de-multiplex all 16
audio channels. An active loop-through output is available for the SDI inputs.
The headphone output is taken before the limiters and mutes the speakers when used. Eight
high-resolution tri-colour bargraphs are provided with user-selectable ballistics and colour
break points. Up to sixteen PCM audio inputs can be selected individually or mixed and
directed to each speaker.
Bargraph meters are arranged in two groups of eight, they can display 1 to 8 or 9 to 16 using
the select button under the status display. Stick-on graticule scales, which may be applied to
the spaces between the front-panel bargraphs, are supplied with the machine.
The eight audio channels are provided at the rear of the unit as four pairs of AES signals on
BNC connectors and four pairs of differential analogue signals. The analogue outputs and line
outputs can be at a fixed level or slaved to the front panel volume control. The analogue and
two line outputs can be muted independently from the menu or under the control of the front
panel mute switch.

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Main!features!!
 Four pairs of unbalanced (BNC) digital audio (AES) inputs four unbalanced line
inputs
 Two auto-sensing SD/HD/3G inputs with loop-through
 Two groups of four tri-colour bargraphs
 Analogue line output and 8 analogue audio outputs, eight pairs of AES outputs
 Headphone connector with speaker mute

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Front!panel!rotary!controls!
Volume
The volume of the speaker and headphone output can be adjusted using this control.
Pressing the end of the control will mute the speaker audio. This can also mute the line
and analogue outputs.
Balance
This control will differentially adjust the level of the speaker and headphone output.
Pressing the end of this control will centre the audio output.
Channel Pair select
This control has no function on the BM-A1-16SHD.
Dolby Mix
This control will set the way in which the monitor will treat the incoming audio. The PCM
position will treat the current audio input as straight PCM encoding and reproduce it
unprocessed on the 16 available channels.
Other positions will have no function, as they are Dolby related and will mute the audio
output.
Menu
Pressing the end of this control will enter the menu mode described in the Menu section.
Input select
Rotating this control will select one of the four audio input sources; Analogue, AES, SDI1
or SDI2.

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Operation!!
Selecting!sources!!
The input source select switch determines which source (Analogue, AES, SDI 1 or SDI 2)
is available to the speaker selectors and bargraphs. AES inputs can be at 44.1 kHz or
48 kHz sampling rate.
SDI!input!mode!!
The unit automatically detects SD, HD or 3G video. The four SDI groups will be demuxed
to give 16 audio signals
Dolby!mode!
Dolby decoding is not available on the BM-A1-16SHD.
Using!the!PROGRAM!switch!!
Keep the switch in the PCM position as the other modes only relate to Dolby features that
are not implemented in the BM-AV2-16SHD. If any of the other modes are selected then
the output will mute.
Directing!sources!to!speakers!!!
Where more than two audio signals are present it may be useful to direct and combine
sources to selected speakers. The left speaker is indicated by a red LED and the right by a
green LED on the top of the bargraphs.
To direct a particular source to the left or right speakers proceed as follows:
Repeatedly press the button under the bargraph corresponding to the input audio signal
required until the top LEDs of the bargraph shows red for the left speaker, green for the
right or both to direct the audio to both speakers. Each speaker can receive a mix of audio
from inputs 1 to 16. Select either lower or upper 8 sources using the select button.
Note that the mix button assignments are retained over power-down.
Status!display!!
The Status display will show general status information related to the currently selected
input such as the source selected and video standard where applicable.

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Rear!panel!inputs!
The BM-A1-16SHD accepts SDI video, AES and analogue audio inputs. Eight differential
analogue inputs are provided on a 25 way ‘D’ type connector. Four pairs of AES
unbalanced inputs are available on BNC connectors. Two SD, HD, 3G auto select SDI
inputs are provided.
Rear!panel!outputs!!
The BM-A1-16SHD provides both digital and analogue audio outputs on the rear panel.
Eight differential analogue outputs on a 25 way ‘D’ type connector and four pairs of AES3 on
BNC connectors are available. The audio carried on the AES outputs are derived from the
currently selected input source (analogue, AES or SDI). In effect, these audio outputs are a
copy of the signals shown on the unit’s bargraphs. The analogue outputs are derived from
the lower 8 inputs (ch1-8). They can thus be a copy of the AES inputs, or two of the
currently demuxed SDI groups. Two line outputs are provided which carry the same audio
as the speakers. The levels of the analogue and line outputs are adjustable in the menu. It is
possible to mute the output from the unit’s speakers by pressing the end of the VOLUME
control. It is also possible to independently mute the analogue outputs and the line outputs
using the volume control.
An SDI loop-through is available which carries a reconstituted SDI signal from the currently
selected SDI input.
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Menu!
Many of the characteristics of the BM-A1-16SHD can be adjusted in the menu. When the
menu is activated, by pressing the NAV rotary encoder, the top level of the menu will
appear. The items in this level can be selected by rotating the encoder and then pressing
it for approximately 0.5 seconds. The second level will then appear and the required item
selected by rotating the encoder and then pressing it. At this point in the menu the value
of the current parameter can be adjusted. To go back one step in the menu press and
hold the encoder for longer than 1 second.
Tip: Simultaneously pressing the buttons under the bargraphs 7 and 8 will completely exit
the menu.
The characteristics that can be adjusted in the menu are shown below.
Top!level!menu!page!
The top level of the menu carries the main areas of operation of the BM-A1-16SHD that
can be adjusted.
1. Level meters - This section allows access to the bargraph colour break points and
ballistics.
2. Line levels - The line output level control can be selected here (either fixed level or
controlled by the volume control). The line output can also be muted, or slaved to the
main speaker mute control.
3. Analogue levels - The analogue output level control can be selected here (either fixed
level or controlled by the volume control). The analogue output can also be muted, or
slaved to the main speaker mute control.
4. Dolby – not available on the BM-A1-16SHD.