The ISM624 4-Zone Rack Mixer is the most sophisticated choice for medium-sized multi-zone sound systems build around a stereo main zone. The unique HybridZone concept allows the three additional mono zones to either carry the same signal as the stereo zone or any of the 6 individual input signals. The front-panel microphone controls plus the comprehensive backside-located zone adjustments like maximum level settings and 100Hz Highpass filters make this unit ultimately flexible while still being user-friendly even for less experienced operators.


  • 6x Stereo input channels, each with Gain control, 2-color Signal/Peak LED and 45mm smooth dual-rail fader
  • 2 Stereo channels rear-side switchable between Line and Phono
  • 2 Stereo channels rear-side switchable between Line and USB (if USB option installed)
  • 1 Stereo channel front-side switchable between Line and frontpanel-mounted 3.5mm stereo TRS AUX input
  • 1 Stereo channel front-side switchable between Line and balanced stereo FOH input (to connect the output of a stage mixer to the venue’s main sound system – available on both front and rear)
  • 2x Mic inputs with rear-side 1/4” TRS connectors
  • Mic1 with additional versatile front-side Combo connector
  • Mutual voice-specific 3-Band EQ plus “on air” switches for mic inputs
  • Front-side talkover switch for Mic inputs with rear-side adjustments for damping (for every mono zone) and sensitivity (only stereo zone)
  • Master section with one stereo output zone (dual 10 LED level meter) and three mono output zones (5 LED level meters)
  • Mono zone sources selectable from Inputs 1-6 or stereo Master signal
  • Each output zone with rear-side adjustable maximum level control
  • Each output zone both on balanced XLR and Phoenix connectors; stereo zone with additional unbalanced RCA output
  • Rear side EQs: 3-band for stereo zone, 2-band or every mono zone
  • 100Hz switchable HP filter and mic exclusion switch for mono zones
  • External output mute contact to shut down master output externally
  • External emergency input with adjustable volume for emergency signal and automatic shutdown of program signal
  • PFL section with volume control and front-side 6.3mm stereo jack
  • Unbalanced record output
  • CE/ROHS compliant



Two USB options are available for the ISM624:

  • Twin-USB option with two USB inputs which can be assigned to channels 3 and 4 (model code ISM624USB-T)
  • Single-USB option with one USB input which can be assigned to channel 3 (model code ISM624USB-S)




  • Signal/Noise >82dB (Line)
  • Crosstalk Damping >65dB (Line)
  • THD <0.05% (Line)
  • Frequency response 20Hz – 20 kHz


  • AC IN (EU version) AC220-250V~ 50Hz
  • AC IN (US version) AC110-120V~ 60Hz
  • Power consumption max. 24W
  • Dimensions W483xH133.5xD183.5mm
  • Weight 4.2 kg



The ISM624 can be modified to suit the customer’s needs. The following options are available (only on order – not for retrofit):

  • Knob style and colour (various knob styles available)
  • Cabinet painting colour
  • Silkscreen artwork and colour
  • Packaging artwork



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