AV Case Study: Hall You Need
A Meyer Sound CAL column array solution impressively answers the call for coverage and clarity in this school hall.
30 August 2024
Text:/ Christopher Holder
A lot is expected of the humble school hall. School assemblies might be the weekly gig but more often than not it’s asked to be a recital centre, a rock concert venue and play host to evermore sophisticated musical theatre. So it is with the College Hall at Brisbane Boys’ College. Completed in 2012, predictably the budget ran out before the full AV package could be installed. Two large drop-down screens with projection handle the visuals and a complement of show lighting was also part of the original installation and thankfully the cabling infrastructure made the cut, but properly catering to the school’s audiovisual requirements has been more ad hoc than desired.
For assemblies, a stopgap column loudspeaker solution made a decent fist at conveying spoken word. For anything requiring proper sound reinforcement, the school’s AV service provider, GL Audio, would bring in extra audio and lighting as required.
HEAT MAPP
In recent years GL Audio has become more reliant on Meyer Sound loudspeaker systems. Product such as the ULTRA-X40 compact loudspeaker has proven to be a good investment – “the power, convenience, coverage and efficiency of that box is phenomenal,” comments GL Audio boss, Greg Loxton.
So it was no surprise that Greg’s first thought was ‘Meyer Sound’ when the school asked him to propose a design for a permanently installed audio upgrade in the College Hall.
“We explored a number of Meyer Sound options in MAPP 3D,” explains Greg Loxton. “The seating area is tricky to cover as it splays out towards the rear and there’s a glass balustrade 10 rows up the raked seating. So we wanted to avoid that.
“I looked at designs using the likes of the ULTRA-X40 but because of the geometry of the space we’d need to install delay speakers. It seemed like Meyer Sound’s CAL column array provided the most elegant solution without any additional fill or delays. It’s not a low-cost solution but once you factor in the extra rigging and cabling required for delays, the numbers stacked up.”
To hard-avoid the glass, the CAL 64 columns are split (electronically) into two different arrays to address the upper and lower sections separately. A 900-LFC sub a side provide ample low-end reinforcement.
CAL STACKS UP
CAL is not your average column array. Shipping in three sizes (32, 64 and 96) it houses all the amplification and processing within the enclosure. Brisbane Boys’ College uses a left/right pair of CAL 64. Each enclosure packs 48 x 20mm tweeters and 16 x four-inch cone drivers. Thanks to the long line and the per-driver amplification and DSP, a high degree of control is possible to best match the audio coverage to the space.
The College Hall operates in a couple of modes. The lower tier of seating is retractable, so GL Audio programmed an ‘Upper Tier’ mode for those occasions. There’s also a ‘Rehearsal’ mode where the main PA is muted and a pair of ULTRA-X40 cover the flat stage area from the overhead truss. CAL is capable of storing four modes onboard, which can be triggered via a six-pin Phoenix connector on the back or via a network connection.
“We mounted each CAL about as high as we could to shoot down over the glass balustrade,” continued Greg Loxton. “The beam steering control is in one-degree increments and the off-axis HF rolloff is extreme. During commissioning, I was sitting in that row of seats behind the balustrade and there was no doubt about when you were sitting in the coverage pattern and when you weren’t.”
To hard-avoid the glass, the CAL 64 column was split (electronically) into two different arrays. The lower half can be muted in the Upper Tier mode.
CAL’s quoted frequency response sees the low end 4dB down at 105Hz. The CAL literature emphasises its suitability to the spoken word and intelligibility in acoustically hostile spaces. But, again, being a Meyer Sound product it’s linear, phase coherent and doesn’t suffer from traditional column array limitations (strangled frequency response and off-axis lobing). And it’s loud. The CAL data sheet quotes a linear peak SPL of 101dB at 60m (M Noise).
“The school likes its high-impact media and packaged content during assemblies, and CAL has no problems keeping up,” notes Greg Loxton. ‘There’s punch and full-range clarity for days.”
NEW LOWS!
When the College Hall is playing host to music productions or rock gigs, more low-end reinforcement is required, and the school now has the luxury of companion subs for all the LF they need. The pair of Meyer Sound 900-LFC are compact low-frequency control elements for low-end extension down to 31Hz. The CAL and 900-LFC is an unusual combination but a killer solution for the Brisbane Boys College hall.
“It wasn’t the obvious solution but the school was on board when we demo’ed a CAL 32 in their space – hearing is believing,” recalls Greg Loxton. “CAL is bit of a technical marvel, really. The electronics and power it packs in that package is amazing. I think the school likes the idea that its so low profile but is really capable. Combined with the 900-LFC sub it really is all the PA the College Hall needs.”
GL Audio: glaudio.com.au
Meyer Sound: meyersound.com
Soho Sound Design (Supplier): sohosound.com.au
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