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Overview
The Shure SCM820 is an 8-channel digital automatic mixer designed for use in speech applications, including sound reinforcement, broadcasting and audio
recording. It dramatically improves audio quality in any application where multiple microphones are required. The mixer uses IntelliMix
®
technology to select
channels to open to the mix bus, while attenuating other channels. The mixing mode is selectable to allow a range of automatic mixing styles.
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extreme
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dual mixer
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INTELLIMIX
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SCM820
SCM820-DAN
SCM820-DB25
SCM820-DAN-DB25
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mix a
mix b
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lockout
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A
A
B
B
manual
smooth
classic
extreme
custom
dual mixer
+0dB
mic
+30dB
mic
phm 48 VDC
CH
+46dB
reset
CHANNEL
INTELLIMIX
0
0
:0
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:D
D
:A
A
:B
B
:C
C
auto link
lockout
line
A
A
B
B
manual
smooth
classic
extreme
custom
dual mixer
+0dB
mic
+30dB
mic
phm 48 VDC
CH
+46dB
reset
CHANNEL
INTELLIMIX
primary
secondary
0
0
:0
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:D
D
:A
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:B
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:C
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INPUTS 1-8
AUX IN
MIX OUTPUTS
MIX A
MIX B
L +R
SUM
DIRECT OUTPUTS 1-8
auto link
lockout
line
A
A
B
B
manual
smooth
classic
extreme
custom
dual mixer
+0dB
mic
+30dB
mic
phm 48 VDC
CH
+46dB
reset
CHANNEL
INTELLIMIX
0
0
:0
E
:D
D
:A
A
:B
B
:C
C
INPUTS 1-8
AUX IN
MIX OUTPUTS
L +R
SUM
DIRECT OUTPUTS 1-8
auto link
IntelliMix
®
Operating Principles
Expanding upon Shure's classic SCM810 IntelliMix technology, the digital
SCM820 delivers seamless automatic mixing by combining the following
functions:
•
Noise Adaptive Threshold (NAT)
manages the audio system by
distinguishing between dynamic audio (such as speech) and the noise
floor (such as air conditioning). It continuously adjusts the activation
threshold, so that only speech levels louder than the background noise
open a channel.
•
MaxBus
ensures that only one channel is opened per sound source,
reducing comb filtering for clear, intelligible speech.
•
Number of Open Microphones Attenuation (NOMA)
attenuates system
gain as additional channels are opened, providing consistent output levels
and better gain before feedback.
• Maintains the perceived ambient sound to achieve a natural sounding
audio program even during long pauses in conversation.
Mixer Modes
The mixer operates in one of five Mix Modes: Classic, Smooth, Extreme,
Custom or Manual. The first three are factory settings that offer a range of
reliable automixing styles. IntelliMix is configurable in Custom mode and
turned off in Manual mode.
Classic
Classic mode emulates the default settings of the classic Shure SCM810
automixer. It is renowned for fast-acting, seamless channel gating and
consistent perceived ambient sound levels.
Smooth
Smooth mode dynamically balances system gain between open and
closed channels. The system gain remains consistent by distributing gain
across channels to equal one open channel. This mode incorporates
IntelliMix operating principles into a gain sharing mixing style.
Extreme
Extreme is an aggressive variation of Classic mode, configured to achieve
maximum gain before feedback by completely attenuating closed channels.
Custom
Custom mode allows individual IntelliMix parameters to be fine-tuned and
tailored from the GUI.
Manual
Manual mode deactivates IntelliMix to operate as a standard mixer.
Channel and mix equalization, output limiter and mix bus routing are still
active in this setting.
Dual Mixer Operation
The SCM820 can operate as a single or dual mixer:
Single Mixer:
Channels are routed to a single mix bus that sends the same
audio to both Mix A and B outputs. This allows the same program to be
sent to different rooms or recording applications. Output gain, parametric
equalizer and limiter can be set separately for each mix.
Dual Mixer:
Two separate buses provide independent automixes for
each mix output. This allows two entirely different mixes to result from
the same set of inputs. This is useful when the mixer is being used for
two applications. For example, set Mix A to Classic mode for sound
reinforcement, and set Mix B to Smooth for a broadcast feed. As a dual
mixer, channels can be routed to Mix A, Mix B, Mix A and B, or neither mix
bus.
DFR and Audio Processing
The SCM820 features two channels of Digital Feedback Reducer (DFR).
DFR uses Shure’s patented Adaptive Notch Filter algorithm to detect
feedback and deploy up to 16 narrow-band notch filters, dramatically
improving gain-before-feedback in a sound reinforcement system. DFR can
be applied to any two channels of the SCM820, including the mix outputs.
Additionally, the mixer provides adjustable input equalization, limiting and a
parametric output EQ to optimize the sound in any application.
Networking
Dante
TM
Digital Audio
Digital audio is carried over standard Ethernet using shielded Cat5e (or
higher) cables. Dante provides low latency, tight clock synchronization, and
high Quality-of-Service (QoS) to provide reliable audio transport to a variety
of Dante devices. Dante audio can coexist safely on the same network as IT
and control data, or can be configured to use a dedicated network.
Audio can be played or recorded to a PC or Mac using Dante Virtual
Soundcard (DVS), using the computer’s standard Ethernet connection.
Remote Control
The SCM820 can connect to a computer or 3rd party control system (AMX,
Crestron) for remote control and monitoring. The web browser-based
graphical user interface (GUI) enables custom IntelliMix configuration and
access to additional features.
Linking Mixers
SCM820-DAN mixers can be linked to form large automixes of up to 12
units (96 channels of audio). Mixers in the same link group operate under
shared IntelliMix settings. A back-panel auto link button enables mixers to
automatically link when they join the network. To link specific mixers,
custom groups can be created and managed from the GUI.
Model Variations
The following table describes the four SCM820 model variations:
Model
Description
Connector Type
Network Card
SCM820
Block
Standard Ethernet
SCM820-DAN
Block
Dante Digital Audio
SCM820-DB25
DB25
Standard Ethernet
SCM820-DAN-DB25 DB25
Dante Digital Audio
Upgrading to Dante
