Shure SCM810 manual Description, System Features, Operating Principles

DESCRIPTION

The Shure Model SCM810/E is an eight-channel automatic microphone mixer designed for use in sound reinforcement, audio recording, and broadcast applications. The SCM810 dramatically improves audio quality in any application where multiple microphones are required. Any low-im- pedance dynamic or condenser microphone (including wireless) can be used with the SCM810/E. Multiple SCM810 mixers can be linked to other SCM810/E mixers, as well as to Shure Models FP410, SCM410, SCM800, and AMS8100 mixers.

SYSTEM FEATURES

Each input channel has a two-band equalizer and three logic terminals. The equalizer reduces unwanted low-frequency audio pickup and makes differ- ent microphone types-lavaliers, boundary and handheld-sound similar. The logic terminals can be used to control external devices.

The SCM810/E operates on 100-120 Vac power; the SCM810E operates on 220-240 Vac power. Each mixer is supplied with a power cord, rack-mounting hardware, and a link cable.

•	Fast-acting, noise-free microphone selection that automatically	•	Peak-responding output limiter with selectable thresholds and
	adjusts to changes in background room noise		LED indicator
•	Automatic gain adjustment as additional microphones are activat-	•	Active balanced microphone-level XLR inputs and an active bal-
	ed		anced Mic/Line level XLR output
•	Last Mic Lock-On circuit that maintains ambient sound	•	Aux-level input with manual level control
•	Adjustable low-frequency rolloff and high-frequency shelving for	•	Front-panel headphones output with level control
	each channel	•	Linking capability for up to 400 microphones

•Channel activation and clipping indicators

OPERATING PRINCIPLES

The operating concept behind the SCM810/E Automatic Mixer is Shure's patented* IntelliMix® circuitry. IntelliMix delivers seamless automatic mixing by combining three separate functions:

•Noise Adaptive Threshold. Distinguishes between constant background noise (such as air conditioning) and changing sound (such as speech) for each input channel. It continuously adjusts the activation threshold so that only speech levels louder than the background noise activate a channel.

•MaxBus. Controls the number of channels that may be activated for a single sound source. One talker activates only one channel, even if multiple microphones “hear” that talker.

•Last Mic Lock-On.Keeps the most recently activated micro- phone open until another microphone is activated. Without Last Mic Lock-On, a long pause in conversation would cause all micro- phones to turn off, which would sound as if the audio signal had been lost. Last Mic Lock-On ensures that background ambience is always present.

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