Gain Management Made Extremely Simple with Apex SL Series

Noise pollution has become an increasing problem across our nation. With the capital cities forming denser populations, entire streets dedicated to bustling nightlife, headline concerts year round and the trend of music festivals clearly on the rise; SPL limitations have become a requirement, not just a feature.

Apex SL

With that, there is a growing level of enforcement in action also. Police, government bodies and privately hired consultants are aggressively tackling noise pollution and volume management.

Just about every venue owner has experienced an irate neighbour or a council visit at some point, and it can be very difficult to justify or prove what volume you were operating at and at what time. Compound this with countless variables like reckless DJ's, ego driven musicians and bar managers making their own calls regarding volume; and suddenly it becomes almost impossible to really know if you were doing 105dB at 3am on a Friday night. This is all before you're threatened with a loss of license or handed a fine that's enough to make your head explode.

The very clever cats at Apex have the perfect gear to assist. They've developed a simple yet highly effective range of solutions that ensure your venue, concert or festival is ALWAYS within the legal limits. The Apex SL Series - Think of it as noise management insurance.


Apex SL


The SL Series is comprised of three devices, the Argos, the Hera, and the Leto.


Apex SL


With its concealed, authority sealable and straightforward setup controls, the Argos can be setup to maintain a ceiling on SPL, either on the road or in fixed installations.

Far more than a gain reducing limiter, Argos’ unique servo-loop circuitry preserves the audio signal quality and the entire dynamic range of the sound programme. This ensures the signal reduction is transparent and helps avoid signal artefacts.

Its unique silence detector also makes it an indispensable tool for live music performance as well as interrupted recorded music and alleviates unpleasant 'pumping'. It enacts a ‘hold’ circuit that maintains the gain reduction while the Argos detects silence.

Connecting the Argos directly to system outputs offers a new level of protection against dangerous DJs, hard-rockers, and extensive repair bills by avoiding dynamic headroom reduction.


Apex SL


The Hera is a Sound Level Control Unit which logs the average and peak RMS sound level pressure over a time period. The Hera can take reference using the included measurement microphone or directly via line or power amplifier inputs.

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

Hera will also detect and log any attempts of system tampering (for example disconnection of the microphone) both of itself and the attached Argos.

Couple this to the Argos, and suddenly the system becomes an end-to-end intelligent gain management solution.

It always helps to see what's going on too, especially when the noise police show up; this is where Leto becomes your best friend.


Apex SL


The Leto is a large remote display designed specifically to provide clear visual indication of current sound levels.

Working in perfect harmony with the Hera and the Argos, the three begin working once user defined thresholds on the Hera are set.

Would you like to limit your venue to 105dB until midnight then taper it off to 100dB until 1am then reduce it to 94dB at 2am? All possible with the Hera, Argos and Leto.

By connecting the Leto to the Hera, a constant display of either the instantaneous or average sound level over a selectable period of time is shown. This offers an easy-to-read display for any DJ or sound operator.

Housed in standard 19-inch enclosure, installing Leto in a rack or into furniture is fast and easy.

Just imagine, next time the noise police show up, you can have a log file of your volume from the night before and show them the current volume of your venue on the spot. Very cool.

To find out more about the incredibly innovative Apex range of solutions, contact Group Technologies today on 03 9354 9133 or at



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