SmartMixer® Five-channel Automatic Mixer


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SmartMixer® Five-channel Automatic Mixer


The AT-MX351a automatic mixer is ideal for meetings, seminars, teleconferencing, worship services, courtroom proceedings, radio and TV broadcasting and A/V applications. All switching is under microprocessor control with proprietary algorithms for instant, seamless operation. An individual priority pre-select switch for each mic/line channel allows choice of one-channel-at-a-time operation, all active, or any mix of moderator override. The last microphone on stays on so that ambient sound is never muted. Plus, any number of SmartMixers can be linked to create a system for large multi-mic installations. The priority control system extends throughout the entire chain.

  • Four automatic Mic/Line inputs, plus Aux in
  • Automatic threshold setting
  • 48V phantom power individually selectable for each channel
  • Limiters on each mic channel prevent individual channel overload
  • Balanced inputs and output, selectable Mic/Line-level
  • Individual gain controls for each channel
  • Switchable manual mode overrides automatic functions
  • Master output level control Pre- or post-controller audio outputs from Mic/Line channels
  • Off attenuation for each input adjustable to -40 dB
  • Sub-D connector for TTL output, plus closure-control input for external control of each channel
  • NOMA operation provided, can be turned on/off
  • Output level meter with Peak and RMS modes
  • Monitor headphone output with adjustable level
  • Internal AC supply
  • Mounts in a single 19" rack space
  • Includes rack mount adapters/li>


Input Impedance Mic 8 kΩ, Line 50 kΩ , Aux 50 kΩ , Link 20 kΩ
Output Impedance Balanced Line 200 Ω, Mic 300 Ω, Unbalanced 400 Ω, Link Out 100 Ω, Preamp Out 750Ω
Maximum Input Level Mic -24 dBV, Line + 27 dBV, Aux +17 dBV
Maximum Output Level +22 dBm
Nominal Output Level (0 VU) Balanced Line +4 dBm (600 Ω), +4.4 dBV (open circuit), Mic -46 dBm (600 Ω), -44 dBV (open circuit), Unbalanced -10 dBV (open circuit), Preamp Out -10 dBV (open circuit)
Maximum Monitor Output 700 mW, 20 Ω load
Maximum Gain 73 dB
Frequency Response 40 - 22,000Hz
Equivalent Input Noise -128 dBV (150 Ω) @ maximum power
Input Attenuation 10 dB
Mic/Line Input Pads 50 dB
Maximum NOMA Attenuation Approximately 20 dB (up to 100 microphones on simultaneously)
Microphone Phantom Power +48 V DC
Control Voltage Out +4 V DC
Power Supply 100V-240V AC, 50-60 Hz, 30W
Operating Temperature 0 - 40 ºC
Dimensions 430 x 238 x 44mm (WDH - including feet, knobs and connectors)
Weight 3.35 kg
Accessories Included System link cable, manual, rack adaptors, AC power supply



AT-MX351A Declaration of Conformity
AT-MX351a Owners Manual