FEATURES: INSTALLATION
Steering around
the velodrome
Keeping the audio off the track was the major challenge for Tom Lee
Engineering at Hong Kong’s new velodrome. Richard Lawn does a lap
The HK Velodrome is located in Tseung Kwan O
WHILST CYCLING HIS WAY TO
gold at the 2006 Asian Games in
Doha, little did Wong Kam-po realise
that his herculean feat would result
in the completion of Hong Kong’s
rst velodrome. Completed some
seven years later at a cost of HK$1.1
billion (US$142 million), the venue
was constructed by the government
amid concerns that athletes who
represent Hong Kong were overreliant on Chinese training facilities.
Located in Tseung Kwan O, the
velodrome occupies 6.6 hectares,
and cycling helmets inspired the
wavy rooftop design proposed by
P&T Architects & Engineers Limited.
To ensure the venue’s use is
maximised, the velodrome also
includes a multi-purpose area for
basketball, volleyball, badminton,
gymnastics and other sports.
Other facilities include changing
rooms, a press conference room
and a pressroom, together with
tness, activity, dance rooms
and a children’s playroom, whilst
a concrete skate park entices
extreme sports enthusiasts in the
adjacent grounds. Working closely
with acoustic consultants AEC, Tom
Lee Engineering Ltd was ultimately
commissioned to design and align
an audio system that would not
only provide announcements and
commentary, but also BGM and
foreground music when required.
The perimeter above the wooden
250m cycling track includes a 3,000
capacity seated audience area. Two
main challenges befell upon Tom
Lee Engineering’s project manager
and designer Danny Wong. Firstly,
the speaker system could only be
suspended on overhead catwalks
in the centre of the velodrome, for
which no single cluster could exceed
100kg in weight. Secondly, the
energy of the loudspeakers had to
be directed purely on the audience
areas so as to not disturb the
drivers. ‘I predicted the coverage by
using the Axys DDA (Digital Directivity
Analysis) software,’ explained Mr
Wong. ‘When combined with the
parameters of the venue, the results
could then be viewed in dynamic 3-D
visualisation.’
The venue measures 150m in
length and 110m in width, but
steering the 100dB SPL energy of
the 25kg U-16 cabinets accurately
towards the seats with no spillage
onto the cycle track was achieved by
using the Digital Directivity Synthesis
(DDS). Mr Wong targeted the sound
dispersion from each cluster to
the seats. ‘For speech, this is fairly
straight forward, but for beam
ste ering musical performances
using lower frequencies, it becomes
Y2 I/O output cards, providing
dedicated speech or music modes,
for which various pre-sets have
been stored. With a Cat-5e network
throughout, the digital signal is
extended down to the performance
area at various patch bays, courtesy
of an Aviom Pro64 network.
Furthermore, 10-port MH10 Merger
Hubs have been added to support
and extend bi-directional parallel
connections to the Pro64 audio
network, boosting the digital signal
as a result of the 100m cable runs.
Adding further exibility, the
venue’s technicians can utilise
the Aviom F6 mainframe, digital
snake and 6416 I/O modules
to connect a portable fold-back
system and portable speakers to
An outdoor auditorium is served
by 70 Technomad Vernal T15
speakers installed under the seats
An AKG DRS700 wireless
microphone system completes
the signal path
Events can be mixed on a Yamaha M7CL console interfaced to
a DME24 mixing engine
competing cyclists below or stimulate
reverberation by hitting the upper
wall surfaces above.
This has been achieved by
suspending eight clusters at
speci c points below the 20m
height catwalk, for which each
cluster consists of four Duran Audio
Axys U-16 speakers. The vertical
slot diffraction HF horn of the
self-powered cabinets is a narrow
horizontal outline, which allows close
spacing of the dual 6.5-inch low-mid
90 PRO AUDIO ASIA July–August 2014
more of a challenge,’ furthered
Mr Wong, who added four B-215
DIFF subwoofers at xed points
from the catwalk. Enhancing the
lower frequencies down to 45Hz,
the 86kg subwoofers have been
logarithmically spaced thanks to
DDS to provide directivity, whilst
extending the throw.
Installed into the rear overhead
control room, a Yamaha M7CL-32
console has been out tted with
MY16 CII Cobranet and Aviom 6416
any of the facility panel inputs. A
Yamaha DME24N digital mixing
engine provides the entire signal
processing throughout the signal
chain, for which the M7CL-32 can
be further con gured and managed
from an iPad via the Japanese
manufacturer’s Stage Mix App.
Operating over a CobraNet
network owing to the original tender
speci cation being drawn up in
2010, the system can be upgraded
to a Dante network over the existing
cabling infrastructure should it be
required.
An AKG DRS700 wireless
microphone system completes the
source to speaker network, for which
The Velodrome is served by eight
clusters each consisting of four
AXYS U-16 speakers
a large inventory of D5 hand-held
mics, lapel and head worn models
were supplied, whilst back of house
communications are enabled via an
ASL intercom system.
In addition, a covered outdoor
theatre was also provided with a
similar sound reinforcement system,
comprising a Yamaha M7CL console,
DME24N digital mixing engine
and Yamaha XP7000 ampli ers.
However, the consultant in this case
stipulated that 70 Technomad 15T
speakers be installed under all the
amphitheatre’s seats to create a
special vibrating sensation for the
audience. ‘The facility managers
can pool the equipment from the
theatre and the velodrome for their
daily changing requirements,’ added
Mr Wong.
In order to maximise their use and
justify their existence, today’s venues
are becoming ever more multifunctional in their nature. As such,
system designers and integrators
continue to be challenged in their
quest to delivery non-compromising
solutions. Whilst perspiring in the
Qatari heat eight years ago, Wong
Kam-po inspired Hong Kong to create
its rst ever velodrome. At the same
time, he unwittingly encouraged Tom
Lee Engineering to a rst in category,
through its creation of a simplistic,
yet highly effective exible sound
system that somehow managed
to navigate all the obstacles it
encountered.
www.tomleeengineering.com
www.gov.hk