Purpose-built to host the upcoming 2021 National Games of China, the new Xi’an Olympic Sports Center in the northwestern province of Shaanxi is outfitted with systems three Allen & Heath product families, including dLive, Avantis and SQ consoles with companion components.
Completed in July 2020 with a total build cost of $1.12 billion, the venue occupies an area of 866,667 square meters and houses three distinct venues: a 60,000-seat athletics stadium with track and field facilities; a gymnasium capable of seating 18,000 people; and a swimming and diving hall that accommodates 4,000 spectators. After the 14th National Games draw to a close, it will transition to hosting international sports events, exhibitions and conferences in addition to acting as a multi-function sports center for nearby cities and towns.
As the plans for the ambitious project were put into action, the contract to design and supply the audio system for the Xi’an Olympic Sports Center was awarded to distributor and installer EZPro, which was tasked with delivering a reliable platform that was also flexible and easy to use.
“The challenges we had to overcome in the system design of Xi’an Olympic Sports Center included long-distance digital audio signal transmission, D/A signal switching and audio signal delay” explains EZPro’s Zhang Xianjun, the project’s technical designer. “But when it came to specifying the six digital mixers for the project, we knew we wouldn’t have to look beyond Allen & Heath’s range of digital mixers, with Dante cards enabling the scalable redundant audio transmission.”
All three of the Allen & Heath product families deployed in the install – dLive, Avantis and SQ – are built on the XCVI 96 kHz FPGA engine that’s designed to deliver a consistent standard of high-resolution low-latency audio across the main and backup systems. To help ensure no disruption to audio in the event of a single point failure, EZPro implemented redundancy throughout the system, from microphone to loudspeaker and everything in-between.
At the input stage, non-redundant analog sources are patched through passive splitters to deliver discrete signals to the main and backup systems. In each of the three venues, a pair of Allen & Heath mixers are deployed, running simultaneously at all times, allowing fast switchover in the event of signal loss. Dante outputs from the main and backup mixers feed the primary and secondary Dante networks respectively, with a third independent network utilised solely for control signals throughout the complex.
At the output stage, amplifiers with both Dante and analog inputs were the preferred choice. The primary Dante network feeds the amplifiers directly while the secondary Dante network output is converted to analog, via Allen & Heath DT168 Dante I/O expanders, to provide a redundant signal to the amplifiers.
For the stadium, a dLive C3500 surface is partnered with a CDM48 MixRack in the main system. As with all dLive systems, the MixRack offers 128 channels of input processing, with a configurable 64-bus architecture, allowing the installer to choose a MixRack I/O configuration to suit the application. For the stadium’s backup system, EZPro opted for an Avantis, a stand-alone mixer offering 24-faders in conjunction with 64 input channels and 42 mix buses, plus a GX4816 I/O expander to mirror the analog I/O of the primary system.
Both the dLive and the Avantis are fitted with Dante I/O cards to integrate with the primary and Sscondary Dante networks. At the other end, a rack of 34 Powersoft Quattrocanali 4804 DSP+D amplifiers — connected directly to the primary Dante network, with the secondary network converted to analogue via DT168 — feed the 136 EAWloudspeakers located throughout the stadium.
In the gymnasium, the main system is also built around a dLive C3500 surface, this time paired with the compact CDM32 MixRack, with an SQ-7 employed as the backup system. The SQ-7’s 32 onboard mic preamps mirror the 32 mic inputs on the CDM32, with 33 faders on hand for control. As with the stadium, both systems integrate with the Dante networks via Dante I/O cards to provide redundant Dante feeds to the gymnasium’s Powersoft amp rack and EAW speakers.
The choice of dLive systems in the stadium and gymnasium is due in part to their modular nature of the system. “In the main stadium and gymnasium, there is no openable observation window in the control room” notes Zhang Xianjun. “As the dLive audio engine is in the MixRack, we can confidently change the location of the surface when required. We can effectively reduce the risk of control interface crashing, and at the same time meet the requirements of a flexible tuning position, ease-of-use and fast setup.”
In the swimming and diving hall, where visibility is not an issue, a pair of SQ-6 mixers are deployed as the main and backup mixer, with Dante cards fitted to both for redundancy of the networked audio, again feeding Powersoft amps and EAWloud speakers. For the natatoriums more modest requirements, the SQ-6’s 24 onboard mic preamps, feeding the 48-channel 36-bus mix engine, was sufficient to meet current and future requirements.
With the facility now open for business, the design and install of the system was viewed as a success by all involved. “The schedule was pressing, yet the sound system installation and commission were finished on time thanks to EZPro’s efforts,” says Zhou Jun, Chief Technical Engineer of the stadium project. “Third-party experts were invited to provide feedback, and they returned a high recommendation. The delivery was accepted without any doubt, and it meets the high Chinese standards for fabulous technical performance.”