Sumo wrestling’s most famous venue adds weight to audio

Tokyo’s Ryōgoku Kokugikan is synonymous with Japan’s national sport, sumo.

Sumo wrestlers practise there daily, and the emperor of Japan has seats reserved for him.

As the venue also hosts events such as concerts and corporate functions, the Ryōgoku Kokugikan’s sound engineer, Sumio Akashio, decided to upgrade the PA system.

The system need to be able to reproduce every sound from the wrestling ring, so that it would be intelligible in the back row of seats on the second-level balcony.

In planning the upgrade, Audiobrains’  Takahisa Ota conducted a simulation, using Martin Audio’s proprietary Display 3 modelling software, and found that the manufacturer’s WPS line array would be best suited to accommodate the various events hosted at Ryōgoku Kokugikan, in terms of size, weight, clarity and SPL.

As well as 80 WPS cabinets, eight SXCF118 cardioid subwoofers were installed to provide the deep bass that had been requested.

Martin Audio’s Torus also features in the shape of eight T1215s – four pairs per side – for near-fill. By being directed downwards, they are able to deliver sound without reflections to the VIP areas, where it had previously been difficult to achieve clarity due to the influence of the roof, suspended above the ring. No other satellite speakers are required, and each pair can be used to control the SPL within its specific area.

Takahisa Ota, who carried out the installation, made the necessary system adjustments to ensure coverage, consistency and control throughout the stadium. “In the vertical pattern, I managed to maintain clarity at the rear, while at the same time suppressing any reflections,” he says.