Screen Africa speaks to Richard Nye, Christie’s Cinema Sales Director for the EMEA
region, about Vive Audio, the audio visual solution provider’s DCI cinema audio
system.
Richard Nye is an AV sales professional with more than 20 years’ experience. He
has overseen the introduction of Christie’s film and digital cinema portfolio to the
EMEA region and has championed the introduction of digital cinema in Europe since
his direct involvement with the UK Film Council and Arts Alliance Media to deliver
the Digital Screen Network, the world’s first large-scale deployment of digital
cinema with over 180 screens equipped, in March 2005.
Today Christie supports more than 45 000 of its digital projectors worldwide, and
about 15 000 of them work in EMEA – with Nye supporting every sale.
Screen Africa: Vive Audio is designed to fit the demands of the DCI audio specs.
Can you outline these specifications and how Vive Audio caters to them?
Richard Nye: Advances in cinema technology that followed in the wake of the Digital
Cinema Initiative (DCI) focused on display, 3D, 4K and High Frame Rate (HFR) – but
at the same time they also considered the audio experience.
The typical audio system in today’s theatres is based on legacy film-era
technologies. Earlier digital audio formats were limited by the available bandwidth
of the storage medium (film), limiting the experience to 16- or 18-bit compressed
audio; however, the potential of DCI content operates well beyond that limit, in
uncompressed linear digital audio formats at 24 bits per sample and up to 96kHz –
all packaged together with the visual, sub-title and metadata into the DCI compliant
digital cinema packages (DCP).
DCI digital audio offers a big leap in performance quality and the opportunity for
exhibitors to have a greater say in the experience they offer to their audiences.
There is huge potential to exploit and develop these opportunities.
Screen Africa: What are the components of the Vive Audio system?
Richard Nye: The Vive Audio line of cinema speakers encompasses screen channel,
subwoofer, surround sound and ceiling speakers, as well as CDA Class D amplifiers
and SKA-3D audio/video processor, while the IMB-S2 DCI-compliant media block is
an additional component of the Christie Vive Audio solution — all part of a complete
product range.
Screen Africa: What features are found in the Vive Audio system that you would not
find in other systems made to DCI standards?
Richard Nye: The key element is that it’s based on ribbon technology which gives
stunning, clear sound reproduction compared to the usual distortions associated
with conventional systems (see below). Additionally, the series also incorporates
the industry’s first ceiling line array surround speaker, which is purpose-built for
cinema audio applications and directs the sound evenly to all parts of the
auditorium. In short, rather than distorted sound which is sometimes too loud,
sometimes not, every member of the audience receives the right level and it is
wonderfully clear – particularly important of course with dialogue.
Screen Africa: What are the functions and features of ribbon driver technology and
what benefits does it offer?
Richard Nye: Ribbon drivers use a very thin, strong and lightweight metallic film
ribbon with circuit traces, suspended between a set of high power neodymium
magnets. When alternating current from an amplifier is applied to the ribbon, the
ribbon is repelled and attracted by the magnets creating vibration of the ribbon.
This generates sound waves. In short these ribbon drivers have wide dispersion and
can handle high power and sound output levels.
The benefits of ribbon driver technology are best illustrated by comparison with
legacy technology, offering many advantages over conventional voice coil/horn
design enclosures in terms of reduced output when enclosed in a magnet and
operating at high temperatures.
There are many other advantages — for instance there are none of the lobing
effects associated with horn design. Unlike horns, ribbon drivers use a direct
radiator configuration and so are not compressed and then expanded; this reduces
distortion.
Furthermore, Vive Audio’s use of ribbon drivers in a line source results in a superior
cylindrical propagation pattern, which by contrast to the horn, has a very wide
horizontal and controller vertical dispersion pattern. This line source design also
better maintains sound pressure levels (SPL) which decay at half the rate of a point
source system.
Vive Audio utilises this speaker system in arrays by stacking multiple identical
speaker cabinets to create curved or straight vertical arrays — a principle that has
become the standard in professional audio sound reinforcement of live events. In
other words, the optimal listening coverage is achieved through the line array set
up’s curved combination of speakers — these arrays can focus sound much better
than the very “undirected’ sound from horn-spread traditional compression drivers
— and deliver a greater dynamic range.
The overall result is a much more compact speaker cabinet, with better sound
dispersion, more consistent and stronger sound pressure levels over longer
distances that are not prone to the distortion, reverb and lobing of legacy speakers.
Good cinema sound is not only about loudness and sound quality but also about
creating an immersive experience. How is Vive Audio designed to deliver that?
Richard Nye: We’ve worked closely with Dolby to not only understand the
specifications of Dolby Atmos but also understand the intent from the post-
production community as they create these audio experiences.
We believe one of the key benefits of our Vive Audio programme is the
development of our single enclosure line array system. With our single enclosure
line array speaker, we’re able to address a key challenge in auditorium design, the
challenge of coverage. Through our patented wave guide design, we’re able to
achieve a wide uniform horizontal dispersion pattern, 90 degrees at 0dBFS with a
smooth -6dB roll off out to 120 degrees.
In addition, we also have developed our patented coaxial articulated line array to
address vertical dispersion. Through this fixed predetermined vertical dispersion
pattern, we’re able to focus (control) the audio energy to a known field or direction.
As an example, our ceiling speakers (LA3C, LA4C, and LA5C) are a parabolic line
array speaker with a 120 degrees. x 120 degrees. dispersion pattern.
For overhead speakers such as in Dolby Atmos, the creative intent is to create an
atmosphere of sound above the audience, in most cases non-directional. This
sensation provides the audience a feeling of envelopment. The benefit of any of our
line array speakers is we are able to control the source of audio, determine its
direction and, through our articulated design, provide a consistent audio experience
from front to back.
Screen Africa: Can you comment on the scalability of the system?
Richard Nye: Our Vive Audio system was designed with scalability in mind to meet
different auditorium designs and audio playback requirements. For example, we’ve
developed a series of five stage channel configurations to meet SMPTE SPL
requirements for auditoriums up to 82m throw (screen to rear wall). Each stage
channel performs at a known maximum through and vertical dispersion to reassure
the system designer the audio performance meets the needs of the environment
and benefits the listening audience.
– Warren Holden
