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 revolutionise its sound systems. The venue’s performance halls now feature L-Acoustics K series and A series solutions, enhancing sound quality and versatility for events.
Makoto Saito, chief sound engineer at Sigma Communications, the company managing Sonic City’s live audio, said: “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.”
The renovation project spanned one and a half years between 2021 and 2023. Last year, the Sigma Communications team began designing and implementing loudspeaker systems acquired from L-Acoustics Certified Provider Distributor Bestec Audio, specifically targeting improved audio coverage in its Large and Small Halls.
The Sigma Communications team designed audio environments for both halls using L-Acoustics Soundvision 3D modelling software. This approach enabled them to create a fully unified L-Acoustics ecosystem that delivered a consistent sonic signature between both venues.
Osamu Nagao, sound engineer at Sigma Communications, said: “The result is a system that sounds more refined while being operationally more flexible than before. With Soundvision, we could precisely model how the systems would perform in these challenging acoustic environments before installing a single box.”
The 2,505-seat Large Hall, with its ideal reverberation time of 1.5 seconds 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 uniform sound throughout the hall by allowing proper dispersion and coverage to reach the furthest seats without obstruction or reflection issues.
Nagao recalled: “Even with a wider proscenium opening, we faced significant space constraints inside the proscenium. 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 coaxial X4i boxes provided 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.
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 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.
Saito said: “Our design called for fewer but more strategically placed speakers with superior capabilities. 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.
Looking toward the future, the team has already identified additional enhancements. Saito concluded: “Next, we would like to widen the opening of the speaker columns in the Large Hall and explore more system rigging possibilities.”