Japan’s Sonic City Halls Upgrade to Versatile L-Acoustics K Series and A Series Japan’s Sonic City Halls Upgrade to Versatile L-Acoustics K Series and A S...

Saitama’s premier convention complex renovates performance halls with L-Acoustics Kara II and A10 systems, delivering superior audio coverage and enhanced venue versatility 

SAITAMA, Japan – April 2025 — Sonic City’s recent seismic reinforcement project became the catalyst for a complete acoustic overhaul. Since 1988, this towering 31-floor facility has served as Saitama’s cultural centrepiece, hosting international conferences with simultaneous translation, major exhibitions, and world-class performances. When structural reinforcement became necessary, Sonic City seized the opportunity to revolutionize their sound systems. The venue’s performance halls now feature state-of-the-art L-Acoustics K Series and A Series solutions, dramatically enhancing sound quality and versatility for every event. 

Renovation Reveals Opportunity for Audio Transformation 

“While the primary purpose of Sonic City’s essential renovations was reinforcement of the building ceilings against seismic activity, we recognized an opportunity to propose a complete transformation of the audio systems in the performance halls,” explains Makoto Saito, Chief Sound Engineer at Sigma Communications Inc., the company managing Sonic City’s live audio. 

The comprehensive renovation project spanned one and a half years between 2021 and 2023. Last year, the Sigma Communications team began designing and implementing brand-new loudspeaker systems acquired from L-Acoustics Certified Provider Distributor Bestec Audio, specifically targeting improved audio coverage in its Large and Small Halls. 

Engineering Solutions Through Soundvision 3D Modeling 

The Sigma Communications team designed detailed audio environments for both halls using L-Acoustics Soundvision 3D modeling software. This approach enabled them to create a fully unified L-Acoustics ecosystem that delivers a consistent sonic signature between both venues. 

“The result is a system that sounds more refined while being operationally more flexible than before,” says Osamu Nagao, Sound Engineer at Sigma Communications. “With Soundvision, we could precisely model how the systems would perform in these challenging acoustic environments before installing a single box.” 

Large Hall: Overcoming Acoustic Challenges with the Compact Power of Kara II 

The 2,505-seat Large Hall, with its ideal reverberation time of 1.5 to 1.8 seconds, hosts everything from classical music performances to rock concerts and dance events. Prior to the renovation, the Sigma Communications team struggled with sound projection from the proscenium to the second-floor seats. Widening the proscenium opening during renovation enabled the newly installed L-Acoustics Kara II system to deliver clear, uniform sound throughout the hall by allowing proper dispersion and coverage to reach the furthest seats without obstruction or reflection issues. 

“Even with a wider proscenium opening, we faced significant space constraints inside the proscenium,” Nagao recalls. “We needed a system that would fit within these tight dimensions while still providing exceptional power and clarity. The Kara II proved the perfect solution, offering remarkable output from a compact form factor.” 

The team designed and installed a centre proscenium array of 10 L-Acoustics Kara II and four SB18 subwoofers, rigged discreetly behind acoustic grills. For comprehensive coverage, eight compact coaxial X4i boxes provide front-fill from under the stage lip, while the hall’s side walls feature nine X4i boxes per side. A pair of X15 HiQ speakers provide on-stage monitoring. The entire system is driven by 10 LA4X, four LA2Xi and one LA12X amplified controllers. 

Small Hall: Enhanced Versatility for Multi-Purpose Use with A Series 

The 496-seat Small Hall serves as a multi-purpose venue for academic lectures, conferences, and piano recitals. Its previous L-Acoustics Kiva and Kilo proscenium array was updated with a more robust system configuration of one A10 Focus and two A10 Wide with one KS21 subwoofer for the centre proscenium array, and side arrays of one A10 Focus and one A10 Wide with one KS21 subwoofer each, for outermost seats on both sides of the hall. For comprehensive coverage, the stage lip houses four compact coaxial X4i boxes for front-fill, while side walls feature six X4i boxes per side. A pair of X12 speakers handle on-stage monitoring duties. 

“Our design called for fewer but more strategically placed speakers with superior capabilities,” says Saito. “We initially wondered if this approach would provide sufficient coverage, but those concerns vanished during our first listening tests. The A10 Series delivers remarkably even dispersion and greater power than our previous system, creating a more well-rounded, solid sound that fills the space beautifully. This has allowed the Small Hall to host a wider variety of events with pristine audio quality, despite using fewer total components.” 

This comprehensive audio coverage has significantly enhanced the Small Hall’s versatility. Live music performances now benefit from a system that delivers excellent low-frequency extension and impact, expanding the types of events that can be successfully hosted in this intimate space. 

Future-Focused Improvements 

Looking toward the future, the team has already identified additional enhancements. “Next, we would like to widen the opening of the speaker columns in the Large Hall and explore more system rigging possibilities,” Saito concludes, demonstrating the team’s commitment to continuously refining Sonic City’s audio experience for local and international guests. 

Learn more about Sonic City at www.sonic-city.or.jp/en  

More information on Sigma Communications can be found at www.sigma-com.co.jp 

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