Marshall AR-DM51-B Digital Audio Monitor User Manual

: June 5, 2024
: Marshall

Table of Contents

Introduction
Features
Package Contents
Front Panel
Control Buttons
Rear Panel
Specifications
Operation
Setting or Changing the IP Address
Updating Firmware
Warranty
Safety
Support
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

**Marshall AR-DM51-B Digital Audio Monitor User Manual

**

Introduction

The Marshall AR-DM51-B Digital Audio Monitor emphasizes a straight-forward, high-quality design and simplicity of operation. The AR-DM51-B exceeds the capabilities of many larger 2RU designs, and is equally at home in production fly packs, news vans, remote OB vans, and equipment rooms.

Features

High Performance Audio

Matches or exceeds many larger 2RU designs
Enough “punch” for the noisiest server rooms (up to 100dB)

Multiple Input Types

3G SDI with Looping Output
HDMI
Analog XLR Balanced – 2 Channels
Analog RCA Unbalanced Line Level – 2 Channels

Flexible Output Types

AES-EBU Pair Balanced XLR (converted from Analog input)
Analog Unbalanced RCA Line Level – 2 Channels 2” Video Display
Provides confidence image of selected HDMI or SDI source
Text indicates Source, Format, Selected Channels and more

Controllable via Ethernet or RS-232 Serial

Remote Control App and Protocol available on Marshall Website Compact 1RU Design Saves Rack Space
Minimum size
Low power consumption, low heat emission into rack

Package Contents

Please ensure the following are included:

One AR-DM51-B Main Chassis
One 12-Volt Universal Power supply (120/240V – 50/60Hz)

Front Panel

Speakers
Provides sound from selected channel pair except when Solo buttons are pressed.
LCD Video Display
When an HDMI or SDI source is being monitored, the associated video will appear here. Also a text overlay shows input source, selected audio channels, and source video parameters.
Note: The LCD display will be black when Analog Sources are selected.
Headphone Jack
Designed to accept stereo headphones with 3.5mm plug.
Control Buttons
Provides quick access for standard equipment operation.
Volume / Mute Knob
Turn the knob to adjust the sound level of both speakers.
Press in on the knob to instantly Mute the speakers.

Control Buttons

Solo Left & Solo Right
Press one of these to isolate the left or right channel only.
Note: Sound will come out of both speakers when a solo channel is selected but will originate from a single source.
Left / Right Arrow Buttons
Press the Left Arrow button to select a lower numbered pair of channels, press the Right Arrow button to select a higher numbered pair of channels.
For example, when monitoring channels 3 & 4, pressing Left Arrow will switch to channels 1 & 2, pressing Right Arrow will switch to channels 5 & 6. The lower-numbered channel audio in a selected pair will play from the Left speaker. The higher-numbered channel audio will play from the Right speaker.
Up / Down Arrow Buttons
Press the Up Arrow to select channel group 1 – 8, press the Down Arrow to select channel group 9 – 16.
Note: This applies to SDI sources only
Input
Press to change input source (input type) in this order:
- HDMI
- SDI
- Analog (XLR Balanced)
- Analog (RCA Unbalanced)
Down Mix
The button on the far right provides a stereo mix from 5.1 or 7.1 surround sources.

Rear Panel

Power Switch
12-Volt DC Power Input XLR 4-pin
RS-232 Serial Control 9-pin D-Sub Port
Ethernet Control RJ-45 Port
HDMI Input
SDI Input and Loop Out
Analog Balanced XLR Inputs (2 channels)
AES/EBU Output XLR (2 channel pair converted from balanced analog input)
Stereo Unbalanced Input 2 channel RCA jacks
Stereo Unbalanced Output 2 channel RCA jacks

Specifications

Model Name	AR-DM51-B
Technical
Video Inputs	HDMI 2.0 x 1

3G SDI x 1 with looping output
Video Formats Supported| HDMI Up to 4K2K@60fps (4:4:4 sampled 8-bits)
SDI up to 1080p50, 59.94,60 (4:2:2 sampled 10-bits)
HDMI HDCP| HDCP 2.2 and 1.4 Supported
Audio Inputs| Analog Balanced x 2 XLR Female Analog Unbalanced x 2 RCA Jack
Audio Outputs| AES/EBU x 1 (Digital Pair) XLR Male Analog Unbalanced x 2 RCA Jack
Signal to Noise Ratio (SNR)| 85 dB
Digital Audio Supported| PCM 2, 5.1, 7.1 channels
HDMI connector| HDMI type A
Serial Control Connector| DB-9 [9-pin D-sub female] supports RJ-45 for Ethernet control
Network Connector| WE/SS 8P8C for control via Ethernet
Mechanical & Electrical|
Housing| Metal enclosure
Dimensions [H x W x D]| 1.75” X 19” x 8.5” / 4.45 cm x 48.25 cm x 21.6 cm
Weight| 7.3 lbs / 3.3 Kg
Mounting| Chassis has “ears” for standard 19” rack mount
Included Power supply| Rated 12 VDC 5 Amps, AC Input (120 – 240 VAC)
Power consumption| 6 Watts Avg
Operation temperature| 0~40 C [32~104 F]
Storage temperature| -20~60 C [-4~140 F]
ESD protection| Human body model — ±15kV [air-gap discharge] & ±8kV [contact discharge]
Relative humidity| 20~90% RH [no condensation]

Operation

Controls on the AR-DM51-B are designed to be extremely straight-forward. To start, simply press the Input button to select the desired source, then adjust the volume knob to the desired listening level.

Metering Type
The default audio metering type is PPM (Peak Program Meter). The metering type can be switched to VU (averaging) using the remote control software or press Mix Down button for 3 seconds.

Monitoring HDMI Sources
When HDMI is selected, video from that source will appear on the front panel LCD display along with information about the video format and selected audio channels. This is a convenient feature allowing quick confirmation that the desired source is being monitored. Channels 1 & 2 will appear on the LED meters and be heard from the speakers. Up to 8 audio channels may be carried in an HDMI program. These are often arranged as 5.1 or 7.1 surround. Use the Right or Left arrow buttons to hear other channel pairs or press the Mix Down button to hear all of the channels as a stereo mix.

Monitoring SDI Sources
When SDI is selected, video from that source will appear on the front panel LCD display along with information about the video format and selected audio channels. Channels 1 & 2 will appear on the LED meters and be heard from the speakers. SDI can carry up to 16 channels, organized as two groups of 8 channels each. Press the Right or Left arrow buttons to hear other channels in the first group (channels 1 – 8).
Press the Up or Down arrows to select the second group (channels 9 – 16) then press Left or Right to select channels in this group.

Monitoring Analog Sources
Connectors are provided for either broadcast level +4DBm balanced audio (XLR) or AV line level -10dBm unbalanced (RCA) audio. When the LED meters are in PPM mode, a broadcast level tone at +4dBm will indicate at the arrow mark on the meter bar, line level 10 at -10dBm will indicate at the same point when connected via the RCA connectors.

In addition to metering and monitoring, analog sources are sampled and converted to AES digital and will appear at the AES/EBU connector on the back panel. The AES connection is balanced 110-ohm type.

Note: If it is desired to connect to equipment that accepts AES digital audio on a 75-ohm BNC connector, please use a 110-ohm to 75-ohm “balun” converter.

Setting or Changing the IP Address

STEP 1
If you know the current IP address you can skip to Step 6.

If the IP address is not known, it maybe be discovered and changed using an RS-232 serial connection. If you do not have a way to connect via RS-232, low cost adapters can easily be ordered on-line by searching for “USB to RS-232 adapter”.

Here’s an example of one from Amazon. Note the pins pointing out from the RS-232 end. This is a “straight through” cable, not a “crossover” or “null modem” version.

Windows will provide drivers for this product automatically once the USB part is plugged in.

STEP 2
Obtain the latest control software from the Marshall website. This will likely come bundled with the latest Firmware update file.

https://marshall-usa.com/monitors/audio/model/AR-DM51-B.php

Find the link on this page Control Software, click it, download the file and UnZip it.

Step 3
Run the AR-DM51-B Remote application. It should run immediately without an installation step. You will see this screen.

STEP 4
Next, click the RS232 button. Allow a moment for the AR-DM51 to respond. If there is only one Com Port running on the computer, the App will usually connect automatically. This is apparent when green bars appear next to Brightness, Contrast and Saturation. When the App does not connect automatically, you will need to select a port number from the pulldown menu. If this is the wrong port number, a small error message will appear. Close the message and select a different port number unit the AR-DM51 responds.

Next, click the Read button.
The Current IP address, Subnet Mask, Gateway and MAC Address should appear.
A small window with “Finish!” will appear as well. You can close that window by clicking **OK

**

STEP 5
To change the IP Address to a custom Static address, swipe your mouse over the various numbers so they highlight in blue. Type over each piece until all the information is correct.
(Note: The MAC address cannot be changed).

If you want the ARDM-51 to operate in DHCP mode instead, simply check the DHCP box instead of typing new numbers.

Click the Apply button. When the Finish! Message appears, the IP address has been changed.

STEP 6
At this point, you can test Ethernet operation of the AR-DM51. (The Ethernet cable should be attached and your computer will need to be on the same network).

Click the Ethernet button, confirm that the address in the upper window is the correct address. If it is not, change it now to match the new address you created.

Click the Connect button. If the app does not communicate with the AR-DM51 immediately, close it, open it again then click Ethernet, Connect.

Try changing something simple like clicking the Solo Left button. The Solo Left button on the AR-DM51 front panel should light. Click again and it should turn off.

Updating Firmware

Firmware updates require an RS-232 connection, they cannot be performed over Ethernet.

STEP 1
Connect via RS-232 as described in Section 9.
Click on the Read button, then click on the Firmware Update button.

A window like this will appear showing the currently installed Firmware versions.
There are two types: Main and Net.

STEP 2
Compare these version numbers to the file or files available on the Marshall website.
If a file with a higher version number is on the website, it is strongly recommended that the Firmware be updated.
To install the update file, click on the Load File button for the type of file you are installing.

STEP 3
Browse to the location on your computer where the file was saved.
Highlight the file and click Open.
This should return you to the Firmware Update page

Click the Burn button.
The message “Write to Flash” will appear and a green progress bar will move.

When the bar moves all the way to the right and stops, the AR-DM51 front panel will light up then go dark.
Use the power switch on the back of the AR-DM51 to turn the power off and back on.
This completes the firmware installation.
To confirm the update, you can repeat Step 1.

Warranty

Marshall Electronics warranties to the first consumer that this device will, under normal use, be free from defects in workmanship and materials, when received in its original container, for a period of two years from the purchase date. This warranty is extended to the first consumer only, and proof of purchase is necessary to honor the warranty. If there is no proof of purchase provided with a warranty claim, Marshall Electronics reserves the right not to honor the warranty set forth above. Therefore, labor and parts may be charged to the consumer. This warranty does not apply to the product exterior or cosmetics. Misuse, abnormal handling, alterations or modifications in design or construction void this warranty. No sales personnel of the seller or any other person is authorized to make any warranties other than those described above, or to extend the duration of any warranties on behalf of Marshall Electronics, beyond the time period described above.

Due to constant effort to improve products and product features, specifications may change without notice.

Safety

Listening to audio at excessive volumes can cause permanent hearing damage. Over exposure to excessive sound levels can damage your ears resulting in permanent noise-induced hearing loss (NIHL).
Please use the following guidelines established by the Occupational Safety Health Administration (OSHA) on maximum time exposure to sound pressure levels before hearing damage occurs.

dB SPL Level: Maximum time exposure
90: 8 hours
95: 4 hours
100: 2 hours