Sennheiser Spectera enhances RF capabilities of Glastonbury’s Arcadia Dragonfly

This year’s Glastonbury festival witnessed the return of performance art collective Arcadia Spectacular and their iconic Dragonfly Stage, a 13-metre-long installation crafted from a transformed Sea King military helicopter. 2025 marked a significant wireless evolution for Arcadia, with Sennheiser’s Spectera wireless system delivering pristine audio performance in one of the most demanding RF environments in the world.

Kevin Gwyther-Brown, business development manager – professional audio at Sennheiser, has worked closely with Arcadia for the past year. “The Arcadia team has been familiar with Spectera since the system was announced at IBC 2024. Their vision was always to move to Spectera, and it came to fruition at this year’s festival,” he said. “For me, this is all about the evolution of the relationship between Arcadia and Sennheiser, both in terms of our collaboration and the equipment being utilised.”

The timing proved fortuitous, as upgrades to the Dragonfly’s lighting and laser systems provided the perfect opportunity to enhance the audio and RF capabilities alongside these other technical improvements. The collaboration extended beyond Sennheiser to include industry partners, with input from Paul Rose and the team from audio rental company AF Live.

The 2025 Dragonfly installation presented unique challenges, requiring reliable wireless coverage across a large area while maintaining audio quality in a busy festival landscape. The performance takes place suspended above the audience, inside a near 100-metre diameter ring of inward facing PA towers. Since the stage is well within the PA coverage, IEMs are essential for all performers, even those not accustomed to using them. Pre-show checks are critical to ensure each artist is comfortable with their mix before entering the structure.

“To meet this need, we required three distinct IEM coverage zones: backstage (for soundcheck), FOH (for engineers to monitor via the same system), and inside the structure,” explained Rob Cook, FOH engineer for the Arcadia Dragonfly Stage. “The performance area is enclosed in a sphere of custom LED panels, which also functions as a surprisingly effective Faraday cage.”

Sennheiser’s audio solution centred on the new Spectera wireless system, which delivered solid performance across the demanding RF environment. Spectera is the world’s first wideband, bidirectional digital wireless ecosystem, offering up to 64 channels (32 in/32 out) in a single rack unit. Spectera’s Audio Link modes provide unprecedented control of latency, audio quality and more for each link, while its bidirectional bodypacks manage both in-ear monitor and mic/line signals simultaneously. 

Six Spectera SEK bodypacks delivered IEM mixes for DJ and MC monitoring, while also providing monitoring for featured artists including Becky Hill. The system’s ability to connect multiple antennas to a single Base Station to extend coverage meant that one antenna could be positioned inside the helicopter structure, and another at the front-of-house position, providing excellent range extension across the festival field. The Base Station was located at FOH and connected directly to the mixing console via MADI, seamlessly integrating with the existing audio infrastructure.

“We can’t deploy vocal monitors due to the limited space, which makes the IEM system absolutely vital,” added Jacob Kuenzler-Byrt, stage manager and deputy technical manager at Arcadia. “Spectera’s power and pristine clarity delivered across the board, allowing each vocal artist to immediately feel comfortable and connected in such a unique environment. This extended coverage was a huge improvement from 2024.”

“Spectera made this setup effortless,” said Cook. “We placed the Base Station at FOH with a local antenna that also covered the entire Arcadia field. A second antenna, connected via a 100-metre ethercon run, was installed at the structure entrance with direct line of sight to the performers. Both antennas transmitted and received on the same TV channel, providing seamless, dropout-free coverage across the field, even including catering.”

Meanwhile, four channels of EW-DX handheld transmitters, equipped with MM 435 capsules, handled DJ and MC vocal duties in a hybrid side-by-side configuration. A pair of omni-directional active antennas were installed inside the helicopter, with the EW-DX microphones operating exclusively within the Dragonfly body and running analogue signals to an SD rack.

Marcus Blight, technical application engineer at Sennheiser, worked alongside Gwyther-Brown to ensure flawless deployment. Both arrived ahead of the show opening to carry out RF checks and ensure everything was locked in and ready – a crucial step in an environment as RF-heavy as Glastonbury.

“RF robustness, flexibility and scalability allowed the team to provide solid coverage across a large area of the site,” Blight noted. “Spectera offered a massive sonic advantage, offering low-latency digital audio to the IEM users and a fast, easy deployment for the crew, who were surprised how simple the system is to use. EW-DX, combined with the MM 435 capsules, provided vocal clarity that cut through the track and immersed the audience.”

“The sound quality of Spectera is unmatched,” adds Cook. “It feels like using a high-end studio headphone amp. The lack of noise floor, superb stereo separation, and flawless coverage allowed me to mix nearly the entire weekend through IEMs. With a suboptimal FOH location and the constant need to stay on comms during Arcadia’s show, that reliability was invaluable.”

“The evolution of our work with Arcadia represents everything we strive for in relationships,” concluded Gwyther-Brown. “From our initial collaboration in 2024 to this year’s full Spectera deployment, we’ve grown together, with each project pushing the boundaries of what’s possible in live performance technology.”

Spectera was also used for Nile Rodgers & Chic’s performance on the Pyramid Stage, along with Dhani Harrison’s Friday slot on the Acoustic Stage.