Dirt, drilling, heavy machinery and bedrock. These are most often the elements and activities associated with mines. It’s tough out there, to be sure, and mining is no game for sissies. But once in a while every mine worth its ore needs a break from the pandemonium of quarrying the Earth to stop and reflect, confer and discuss matters of import.

Of course, you can’t do any of that down in a mine shaft or a pit where a cacophony of heavy work is being done. You need a safe, quiet, air-conditioned space where you can bring issues of consequence to the table and this space needs equipment, but not of the heavy kind. It needs state-of-the-art AV and that’s exactly what was installed at the newly erected Parsons Hall at the Assmang Khumani mine near Kuthu in North West Province by the Bloemfontein branch of AV specialists Audiosure, coordinated by Martin Prinsloo (First Technology – sales manager, Northern Cape).
The primary uses for Parsons Hall are hosting labour-related issues, seminars and conferences. Measuring 30m x 15m in total it was also designed to be divided into two smaller 15m x 15m venues, each with its own conferencing, projection and audio systems. Audiosure provided a complete turnkey solution to these specifications.
Let’s dig a little deeper.

Audio

The main audio system chosen for the venue was the Martin Audio OmniLine. The OmniLine is a ’micro line array” system aimed at commercial installations that, according to Martin Audio, offers: …”unprecedented accuracy in a wide variety of architectural environments,’ and uses only one channel of amplification per array in most scenarios. The OmniLine is optimised for the clear pre-production of speech or programme material.

Each OmniLine enclosure consists of two 3.5′ LF drivers and five 0.55′ soft dome tweeters, can handle 50W AES, 200W peak and has a max SPL of 104dB continuous and 110dB peak. It has a 100 degree horizontal and 5 degree vertical dispersion (-6dB).

As far as Parsons Hall is concerned and because it was designed to be divided into two venues, two separate albeit unified (if needed) systems were spec’d.

At the front of the hall a hang of eight OmniLine enclosures per side were installed, partnered to four Martin Audio AQ210 subwoofers (two per side). For amplification of the front system a Martin Audio (Powersoft) MA2.8 was installed that delivers 1 600W to a 4Ohm load across four channels. An MC2 T2000 was provided for the AQ210 subs.

The rear system, when the hall is operating in “dual venue mode’, is half the size of the front system; four OmniLine enclosures per side paired to two AQ210 subwoofers (one per side). Half the system requires half the power so a dual-channel Martin Audio MA1.4 was supplied that delivers 800W across two channels. Once again, an MC2 T2000 amplifier powers the subwoofers.

An Allen & Heath ZED 14 mixer was also supplied, along with six Clock Audio radio microphones for roaming presentations.

The control and distribution system employed was an Allen & Heath IDR-8 ST system with its accompanying range of PL series controllers. The IDR-8 is a 16×16 matrix mixer that features: “…an extensive array of audio management tools designed to reduce the need for additional devices for an installation.’ Two PL3 and two PL7 control panels, which plug into the IDR-8 via CAT5, were installed strategically throughout the hall for mode and parameter control, bringing the control of the processor to the venue.

“One of the overriding factors for us was the flexibility of the IDR system,’ says Prinsloo, “with the PL controllers setup to do any one of a comprehensive list of functions as basic as volume and input select to complex matrix routings and processing. The ability to remotely control and monitor the IDR over a standard network also played a part in the selection of the unit.’

Additional audio components installed in the hall included eight Quad Industrial C8 ceiling mount speakers for the foyer and bathrooms and powered by a DSPPA MP600 on 100V lines. Three 8′ Wharfdale Pro Titan 8 passive speakers powered by a Samson SX1800 were installed to cover selected outside areas.

Of course, conferencing often requires specialised conferencing equipment so to this end a comprehensive Taiden system was deployed. Two Taiden HCS 4100s – fully digital conferencing system control units – were the units of choice. The Taiden system is completely wireless and uses infrared transmission of digital audio from the delegate units (microphones) to the control unit. The delegate unit digitally encodes the microphone signal at 48 kHz (30 to 20khz bandwidth) and modulates audio and data signals for bi-directional transmission via infrared.


Audio visual

When considering the audio visual requirements at Parsons Hall and being that it is situated on the site of a mine, it became evident that the installation would not be without challenges. Prinsloo explains: “With four ultra-heavy crushers turning car-sized rocks into dust less than 500 metres away one can truly appreciate the intensity of the ground vibrations. Even with proper heavy duty brackets installed the chances of a projector vibrating off the screen over time could not be excluded.’
After some deliberation around the subject, two Vivtek D6510s were selected because of the array of features that would help combat these potential problems. The D6510s allow the user to remotely adjust the lens by moving it up, down, left or right to compensate for potential drift. Also, the D6510 allows zoom and focus to be adjusted via the remote control and the dual lamp system can be used as a redundant backup or to supply extra brightness when needed.

The projectors both utilise VGA and Audio over CAT5 systems before transmission through a Taiden TMX-00808 matrix. The TMX-0808 offers 8×8 VGA and audio matrixing.

Finally, two 240′ motorised screens were installed for each portion of the split venue.

The wrap

Finding a complete audio visual solution that meets the demands of an array of needs can often be a daunting task for installers. The fact of the matter is that clients need to be able to accomplish a specific amount of tasks, often across multiple venues and finding the right combination of equipment can be a challenge. However, in this instance, Audiosure executed a turnkey, one-stop solution that was flexible and powerful for Parsons Hall at the Assmang Khumani mine and robust enough to withstand the roughest of environments.