‘It can bring you to tears': is this the world's most beautiful sounding nightclub?

The Guardian

21-07-2025

It's 8pm when DJ Lag steps up to the booth for his sound check at Open Ground, a dance venue in western Germany. It has been described as the 'best-sounding new club in the world', and when the first track plays you can hear why.
Rotund bass lines roll across the acoustically treated room, propelled by an extraordinarily powerful, horn-loaded bass enclosure named the Funktion-One F132. High-pitched melodies and intricate textures develop with startling clarity. And as for the call-and-response ad-libs – they sound as if the vocalists are standing only metres away.
Open Ground certainly knows how to make a great first impression. 'I remember the moment exactly,' recalls Eddy Toca, AKA Piccell. The Angola-born DJ, who is now based in Dortmund, is here to play alongside DJ Lag and the rest of Barulho World, his afro-electronic collective. 'It was a flash. It was a bang. We couldn't compare it to any other place we've ever played. It's like a dream.'
Open Ground is located in Wuppertal, just outside the Ruhr valley, a location known predominantly for its 125-year-old suspended monorail and as the home of the late Pina Bausch's famous dance theatre. It's a five-hour train ride from Berlin, a city that has often stolen the electronic music spotlight from the rest of Germany due to its mythologised hedonism and notoriously selective scene, credited to clubs such as Berghain. Yet since opening in December 2023, Open Ground has become a pilgrimage site for nightlife enthusiasts and DJs from all over the world. British musician Floating Points has called it 'probably the greatest-sounding club in the EU.' Drum'n'bass DJ Mantra said: 'It can almost bring you to tears.'
There are more than eight decades of embodied music knowledge between Open Ground's two founders, Markus Riedel and Mark Ernestus. Prior to the club, Riedel worked for 20 years at the esteemed Berlin-based record label Hard Wax, which was founded in 1989 by Ernestus, who is known for his pioneering work in dub techno with Basic Channel and Rhythm & Sound. In 2008, Riedel relocated with his family back to his native Wuppertal to take a position at his brother's company, a global communications firm that lists Formula One, the Fifa World Cup, Eurovision, and the Olympics as its clients.
Eight years later, the city approached the Riedel brothers with an idea to convert a decommissioned second world war bunker near the train station into a nightclub as part of its urban renewal efforts, though the project itself has received no cultural funding. Entirely financed by Riedel's brother Thomas, the renovation took seven years and involved big recalibrations: they had to consolidate several smaller rooms, saw out the concrete ceiling, and account for an unexpected water reservoir space that now serves as the ventilation room and the smaller 'Annex' dancefloor. The team even changed the air-conditioning system to accommodate for the ideal positioning of the sound design.
Riedel, Ernestus and Open Ground's music curator Arthur Rieger take me on a tour before its opening hours. Stepping inside the space, divorced from the usual chatter of patrons, there is an immediate, monastic hush that envelops the entire club. The acoustician, Willsingh Wilson of Wax Acoustics, installed wall-to-wall grey fibre panelling throughout the entire space (rather than only in the music areas, as is the case with most clubs). This patented material absorbs disruptive sonic reflections, providing a prime container to exalt the Funktion-One and its full spectrum range, from high-pitched bird chirps of 20 kilohertz to low, vibrating frequencies that stoop to 24 hertz. Open Ground is also one of the rare indoor installations of the potent F132 subwoofers.
Ernestus does not consider great sound a luxury, but an imperative. 'When humans were hunters and gatherers, our ears were our alarm system,' he says. 'The ears are one of the first organs that develop in the embryo and are hardwired to the parts of the brain that process stress. Even 50 decibels, which is a quiet room with a fridge, for example, can be damaging in the long run. It increases your risk of cardiovascular disease. Basically, there's almost no healthy noise.'
Prolonged exposure to poor-audio quality and inadequate acoustic treatment in particular is an occupational health hazard. The human nervous system perceives distorted, harsh or poorly balanced sound as a low-level threat, triggering a cascade of physiological stress responses that can manifest as increased cortisol production, muscle tension, cognitive fatigue and sleep disruption. Compounded long term, this can lead to an increased risk of heart disease and metabolic disorders, such as type 2 diabetes.
The brain also compensates for the dissonant auditory input with headaches and eye strain. Yet paradoxically, poor audio quality will often cause DJs to increase the volume of the monitors to compensate, only to further aggravate the body. This is why, in its most extreme forms, sound has been used by military forces as psychological sonic warfare to induce anxiety attacks, ear pain and hypertension.
Ernestus has had tinnitus since the age of 18, so he is intimately aware of music's physical toll. 'Normally if I am in a club for most of the night – tinnitus aside – I can feel just how knackered I am the next day from the stress level. Here, I sleep only an hour longer maybe, but I feel fit.'
If acoustic investment is so vital, why is it systematically undervalued? According to Ernestus, the barrier isn't necessarily financial, but a matter of misplaced priorities. 'We take in about 90% of sensory information through our eyes, and I think it is because of that that the visuals are always overrated,' he said. 'Club owners who I know would typically rather spend €50,000 on an amazing LED installation than the same amount on acoustic treatment.'
At Open Ground, there also appears to be a commitment towards artist welfare that can only be intuited by people who have spent a greater part of their lifetime at raves. Backstage, artists have private showers to freshen up after long, irregular hours on the road. There's a bathroom adjacent to the booth for DJs pulling night-long shifts. Before the show, artists gather backstage for a catered vegetarian dinner because healthy meals are hard to come by on tour. 'A lot of the planning came from our own experience. If you give an artist or DJ ideal working conditions, it translates into a good performance,' Riedel says.
Optimising for every detail ultimately benefits audiences, too, in subtle ways that the casual clubgoer may fail to notice. Annex and the main dancefloor Freifeld are strategically designed and lit for individuals to dance comfortably on a sparse floor. In the indoor sitting area, there are small monitors playing out the set from Freifeld in real time, so clubbers can rest while still engaging with the music. Throughout, no one needs to raise their voices to converse with one another.
Returning to the dancefloor after my tour, I watch a twentysomething woman in the front row flail her entire body to and fro, losing herself in a wild, interpretive dance. The night is still young and the main floor still semi-empty, but she moves as unselfconsciously as though it is peak time. Gazing at her, I think back to what Markus's wife, Christine, told to me earlier in the night: 'The sound is so good, you don't need drugs.'