Hollywood Bowl’s Audio Revolution: A New Era in Live Sound

On the concert stage, sound engineers work hard to control noise. They deal with problems like a kick drum affecting a vocal mic or a guitar amp interfering with a monitor feed. Traditional methods such as equalization and compression have been used for years to handle these issues.

This summer, a breakthrough occurred at the Hollywood Bowl. A machine learning system called Source Intelligence, developed by French company L’Acoustics, listens to every microphone on stage. It isolates a vocalist’s voice from other sounds in real time. This innovation brings up to 40 decibels of rejection of unwanted stage noise. L’Acoustics’ CEO, Laurent Vaissié, notes it is 20 decibels better than existing technologies.

Fred Vogler, the Bowl’s principal sound designer since 2003, describes the change as surprising. It eliminates the interference from instruments, focusing solely on the vocal sound. Source Intelligence is just one aspect of the venue’s comprehensive audio upgrade. This includes the new L Series line array system and a unique immersive surround installation.

The Physics of the Upgrade

The new L1 system, L’Acoustics’ showcase line array, represents a significant change in format since the modern line source array was created in 1993. Line arrays use multiple speakers in a vertical column. These speakers shape sound distribution across a vast area. However, gaps between the speaker boxes can cause coherence loss, explained Vaissié.

The L1 addresses this by integrating speakers into a reshaped cabinet which reduces interface numbers. This creates a system 30% smaller than its predecessor but more powerful, transforming the audience experience. The variance in volume from different seats has decreased from nine to roughly three decibels, enhancing sound consistency.

According to Vogler, the upgrade from the K Series to the L1 Series surpassed expectations with its low distortion and clear, crisp sound.

AI in the Mix

The AI component of the upgrade brings machine learning into live sound production. Source Intelligence uses algorithms to isolate a singer’s voice amidst the chaotic sounds of a live concert, delivering a purer signal to the mix.

Originally designed for DJs to separate audio tracks, the technology has been repurposed for live sound. Mixing engineers can now enhance vocals without amplifying other sounds, resulting in better sound clarity for audiences.

Source Intelligence is already in use on major global tours, including those by Harry Styles and Bruno Mars, demonstrating its industry impact.

The Immersive Frontier

The most forward-looking aspect of the upgrade is the new immersive surround sound system, L’Acoustics’ L-ISA platform. This system envelops the entire amphitheater in spatial audio, making the space feel like a concert hall even in outdoor settings.

L-ISA has two primary functions: simulating enclosed spaces and distributing sound across the seating area. Scott Sugden of L’Acoustics notes its unprecedented scale. Vogler uses it carefully for orchestral and pop performances, enhancing the music experience without being overtly noticeable.

A Century-Old Venue, a 21st Century Bet

Founded in 1922, the Hollywood Bowl’s current structure dates back to renovations in 2004. L’Acoustics has long been a partner, with the venue first installing the K1 system in 2013 and now the L1. Vu from the Bowl states the emphasis on sound quality continues into the present.

Throughout the summer, more than 130 shows will use the house system, underscoring trust in this new audio infrastructure. The combination of L Series, Source Intelligence, and L-ISA positions the Hollywood Bowl at the forefront of smart, precise, and immersive live music experiences.