Apex HERA Sound Level Controller

Hera, will not only log the average and peak RMS sound level pressure over a time period, but Hera will also detect and log the attempts of system tampering (for example disconnection of the microphone).

HERA Sound level controller front and panels

You can choose between different 3 modes of operation: use the measurement microphone provided, the line inputs or the power amplifier inputs as level measurement reference.

Argos’ unique servo-loop circuitry will preserve the whole audio signal quality and the entire dynamic range of the sound programme. Its unique silence detector makes it an indispensable tool for live music performance as well as interrupted recorded music, it will prevent pumping artefacts when the signal returns.

Configuring the Argos in fast mode and connecting it directly to your power amplifiers output, in parallel with the speakers, will protect your sound system against dangerous DJs, hard-rockers and extensive repair bills.

Use the Argos together with the Apex Hera, they will be your neighbours dream team !

The logs can be easily consulted by any user directly from the front panel or retrieved on a computer and printed out. Hera also offers two logic outputs that may be used to control external devices or mains cut-off if a certain threshold is being exceeded. This threshold value may be scheduled to allow for different sound levels at set times.

All settings are pin code protected and can easily be set from the devices' front panel.

Apex Hera is delivered with a measurement microphone and this is factory calibrated for perfect accuracy.

Hera also offers an automatic calibration function for remote microphone distance compensation. This is imperative in most venues, since the measurement microphones should be placed out of reach.

Optionally you can connect the Apex Leto large deported display to the Hera so that the audience, band or DJ may have visual sight on the sound pressure levels at any time.

The Hera may be used together with the Apex Argos. The Argos will then be slaved onto the Hera's measurement and threshold.

Use the Hera together with the Apex Argos, they will be your neighbours dream team !


  • Directive 2003/10/EC "Noise at work"
  • fixed installation: bar, theatre, concert venue, ...
  • on the road: mobile DJ, live concert, ...


Key features

  • stand-alone warning and cut-off microprocessor-based controller
  • factory calibrated for accurate measurement
  • all settings may be made from the front panel and are password protected
  • average and peak RMS sound level logging over an user adjustable time
  • system tamper detection and logging
  • easy computer log read-out through standard serial port (without having to switch off the device)
  • two separated logic outputs for controlling external devices and mains power cut relays, all set / reset times adjustable
  • use in combination with Argos for the ultimate in sound level monitoring and management

General features

  • 14-days sound level log (if registered every 15 minutes)
  • possibility to schedule different threshold per day and weekdays
  • optional remote large level display


Input / Output

Measurment microphone input

Interconnection to Argos

RS-232 for memory read-out from a computer

Output to Leto deported display


Range 55dB-120dB

"A" filter accurancy 27Hz-20kHz: +/- 1,2dB

Relay Outputs

Connections: GND, OUT1, OUT2, +12V

Current limiting on each output

Relay absence detection


Dimensions 19 inch / 1 HU

Supply voltage 90-230 Vac

Shipping weight 2,35 kg

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