MT ANNAN HIGH SCHOOL INSTALLS DUAL-PURPOSE PA

THE VENUE

Established in 2003, Mount Annan High School is a co-educational public school in Sydney’s Macarthur region. The school’s motto of ‘Strive, Respect, Cooperate’ supports its culture of developing student leadership and creating a positive impact on the wider community. Mt Annan High School produces a variety of talent from its student body, be it in performing or creative arts, sport, public speaking and debating. Situated in pleasant surroundings, you’ll find music and drama studios on the premises, as well as spacious classrooms and a Learning Centre for Year 12 students.

THE CHALLENGE

Mt Annan High School’s basketball court hosts more than just ball games. Here, weekly school assemblies take place, along with musical performances and other public events requiring sound reinforcement. But here’s the conundrum — the PA system is configured differently for each. Assemblies see students facing the width of the court, while performances feature the stage at the far end with the audience facing the court’s length. This effectively required two separate PA systems to accommodate both applications, but with central control.

THE FIX

The NAS Projects Team devised a solution to adequately cover the basketball court’s dual-oriented PA requirements. At the heart of the solution was the concept of running two ‘modes’ to discretely accommodate both assemblies and performances. Installation was carried out by Primo Electrical, with education supplier Kookaburra Educational Resources helming the project.

Six dBTechnologies Arena 15 loudspeakers hang on opposite walls, powered by three dual-channel InterM V2-5000 1000W amplifiers. The Ashly Protea ne24.24m 12 x 4 digital signal processor manages all six outputs to the Arena 15s, with carefully tuned DSP settings for both Assembly and Performance modes.

While Assembly mode engages Speakers 2, 3, 5, & 6 (see diagram), Performance mode uses 1, 3, 4 & 6 to throw sound down the length of the court. In terms of DSP, Performance mode boosts the lows and kicks up the highs for a more flattering and musical frequency response, whereas Assembly mode filters out a lot of the low end for a tighter response optimised for speech reproduction. Switching between the two modes is as painless as pushing a button on an Ashly WR-2 switch installed at the stage end, which recalls the respective DSP preset on the Ashly Protea ne24.24m processor.

In Assembly Mode, an Ashly FR-8 mixer handles all inputs including three wireless microphones (Chiayo Performer mics with Audio-Technica capsules), projector audio, iPad input, and computer input. Performance mode puts a larger mixer in the circuit to cater for the connections at the stage end, with a 50m Maximum 16 x 4 multicore carrying the signal.

It was important to keep reverb under control, so the six dBTechnologies Arena 15s were mounted relatively low to steer sound waves away from the reverberant ceiling void. Ashly’s DSP prowess also came into play, with the speaker outputs tuned for the room to keep reverb-prone frequencies in check.

THE RESULT

The ability to instantly repurpose the court’s PA system without moving speakers or re-running cables has benefitted the school greatly. Mark de Gruchy of Mt Annan High School says the upgrade definitively trumps the school’s previous system. “We did have speakers in there before but they weren’t very efficient. Now, being able to switch between Performance and Assembly modes is 100% better than what we had before — actually, 200% better! The speakers are pretty clear, and everyone involved in the project had a great work ethic. I was very impressed.”

GEAR LIST

• 6 x dBTechnologies Arena 15 speakers
• 3 x InterM V2-5000 power amps
• 2 x Chiayo Performer radio mics
• 1 x Ashly Protea ne24.24 processor
• 1 x Ashly FR-8 fader remote
• 1 x Ashly WR-2 wall remote

dBTechnologies Arena 15

• Power: 400W RMS
• Max. SPL: 129dB
• Freq. Response: 80Hz – 19kHz
• Directivity: 90° x 40°
• Weight: 23.7kg
• Crossover Frequency: 2kHz

InterM V2-5000 (all specs at 8Ω)

• Power: 1000W
• Freq. Response: ±0.5dB (20Hz – 20kHz)
• Input Sensitivity: 1.4V
• Voltage Gain: 36dB
• Signal/Noise Ratio: >106dB
• Weight: 12.5kg

Ashly Protea ne24.24m

• Expandable up to 24 channels
• Mic/Line inputs
• 24-bit A/D-D/A conversion
• 31 preset locations
• Multi-level security
• Intuitive user interface
• Five-year warranty

NATIONAL AUDIO SYSTEMS

Call 1800 441 440
Email sales@nationalaudio.com.au
Visit www.nationalaudio.com.au