The university is part-way through a refurbishment programme for all of its physical learning spaces - lecture theatres to old-school graduates - which is taking place throughout its Cathays Park and Heath Park campuses. In addition, two new buildings are under construction - one in Cardiff’s Central Square for the University’s School of Journalism, Media and Culture (JOMEC - to be shared with BBC Wales) and the Centre for Student Life, located next to the existing Student Union.
150 Yamaha VXC8W ceiling loudspeakers have been installed in the newly-updated lecture theatres, while 99 VXC6W will be installed in the new buildings.
Harmonia Consulting has been working with the university for the past three years, designing both the acoustics and the AV systems for the ongoing upgrades, as well as for the new spaces. The systems have been installed by systems integrators GV Multimedia and Reflex.
“We chose to use Yamaha VXC series loudspeakers in all the spaces with low ceilings, where cabinet loudspeakers hanging from the ceiling would obstruct sight lines, make the space feel cluttered and there wasn’t sufficient space to locate central loudspeakers with enough proportional directivity for the necessary acoustic gain,” says Harmonia consultant Sam Williams.
“A distributed loudspeaker approach was the obvious solution and, with ceiling speakers located closer to the listeners and further away from the lecturer microphones, it also meant that we could maximise gain before feedback.”
The choice of loudspeakers was based on extensive testing and comparison of different models. “We had several key tests, including level variance over nominal coverage angles, because many two-way, coaxial-‘ish’ ceiling speakers have inconsistent spatial variance over the nominal coverage area and beyond,” says Sam.
“Speech and music quality were also very important, in the latter case because the systems are used for program audio, as part of the teaching. However, many two-way or larger loudspeakers which have reasonable directivity often significantly compromise audio quality.”
With all the tests completed, the Yamaha VXC series was chosen because it satisfied all of the acoustic and technical requirements, as well as being at the right price point.
“The fact that Yamaha had low profile options and variable sizes of ceiling speaker meant that we could deliver a project with consistent tonality and quality, which was also cost effective to the client,” says Sam.
Every space was the subject of a full acoustic model, which was also used to simulate its electroacoustic performance. This allowed the intelligibility to be predicted and maximised, through the combination of speaker placement, bespoke acoustic improvements and the use of DSP.
“We eliminated long reverberation times, significantly increasing speech intelligibility,” says Sam. “However, a side effect of distributed systems can be a sense of acoustic localisation. This was overcome by using a slight DSP delay - so that the direct sound arrives at the listener before that from the nearest loudspeaker - which also helps to keep students focused toward the front of the space.”
A final advantage of choosing the Yamaha VXC series was the benefits they bring to systems integrators. “The VXC series is not too heavy, unlike units we have previously used, and they are easy to install. This helps the integrators to have a positive project experience, which is very important to us,” says Sam.
The purpose of this major, ongoing project is to provide the highest quality learning facilities at Cardiff University. Thanks to their ability to deliver benefits on a number of different levels, Yamaha VXC series speakers will play a key role in improving the learning experience for over 30,000 students each year.