Able to trace its history back to 1865, Munich’s Gärtnerplatztheater stages performances from all areas of musical theatre, from musicals and modern operetta to revues. Its grand auditorium is a classical tiered theatre that can accommodate just under 900. There is also a foyer, which is occasionally used for musical events, and an orchestra rehearsal room that also serves as a location for chamber music performances and recitals. In addition, the rehearsal stage is sometimes used for chamber operas, and can accommodate up to 100 people.

Recently, the theatre made the transition to digital microphone technology from Sennheiser.

‘We’ve been using Sennheiser wireless solutions since the beginning of the Mikroport era,’ says Dirk Buttgereit, head of the sound department since 2003, using a term that indicated the theatre has a long history of using Sennheiser wireless systems. ‘Even back in the 1980s, the theatre was equipped with wireless systems from Sennheiser. These included a system working in the VHF range, which we operated with an impressive 12 channels.

‘As part of a refurbishment in 2007, we acquired 24 Sennheiser wireless channels from the 3000 series. In 2014, we added 12 channels from the 2000 series, making a total of 36 channels available overall. Unfortunately, the “digital dividend” and the ensuing restriction in frequencies did not leave us unscathed, but we were able to have our equipment converted to suitable frequency ranges by the Sennheiser service team. We have always had only the very best of experience with the service team in Barleben.

‘In summer 2021, the acquisition of a new Lawo digital mixing console gave us the opportunity to convert the entire theatre to digital wireless systems. Nowadays, there are so many wireless signals even inside a theatre that the Sennheiser digital microphone system, which does not generate any intermodulation products, is a big help in efficiently using the spectrum.’

Forty channels from the Sennheiser Digital 6000 series were duly acquired, with 20 EM 6000 two-channel receivers installed in a rack in a temperature-controlled equipment room. The audio link to the console is digital via a Dante network, as is receiver clocking. The signal flow to the power amplifiers is predominantly digital – according to Buttgereit, latency within the digital chain is ‘not an issue, because it remains below the threshold of perception.’

Forty ultra-compact SK 6212 bodypack transmitters and four SKM 6000 handheld transmitters fitted with Neumann KK 205 capsules (super-cardioid) transmit their signals to these receivers. The theatre’s extensive microphone equipment includes Sennheiser MKE 1 clip-on microphones (omnidirectional), with more of these microphones to subsequently be added.

‘The MKE 1 are amazingly resistant to sweat, and if we consider just how much some performers tend to sweat during a show, this is an extremely important factor for us,’ Buttgereit says. ‘All in all, we currently have 60 MKE 1s in use.’

At the Gärtnerplatztheater, the Sennheiser Digital 6000 systems are operated in the A1-A4 frequency segment (470-558MHz). AD 3700 antennas are used as active broadband directional antennas, and are placed in the same positions as their predecessors, using pre-existing wiring. The antennas are connected to a Sennheiser ASA 3000 antenna splitter that supplies signals to three cascaded groups, each with eight EM 6000. If the number of receivers rises in the future, more outputs are available on the splitter.

The frequencies that are used in the individual performance venues at the theatre were calculated using Sennheiser WSM (Wireless Systems Manager) software when the systems were set up in summer 2021 and, according to Buttgereit, they have not been changed since.

‘This is a fixed installation in which normally nothing fundamentally changes. We have been using the new Digital 6000 systems for more than a year now. So far, we haven’t noticed any interference or other artefacts that might make it necessary to change individual frequencies.’

Before the performances begin, the bodypack transmitters and their microphones are handed out to the performers from a mobile workplace. This so-called ‘service station’ is located in a corridor near the access area to the stage and, in addition to bodypack transmitters, headsets and microphones, it also provides all the necessary accessories, including various adhesive plasters that are needed to attach the tiny microphones to the performers’ skin. The sound engineers can keep an eye on all the relevant parameters of the wireless connections with the aid of the WSM software installed on a laptop.

Both handheld and bodypack transmitters used at the Gärtnerplatztheater are powered by Sennheiser BA 60 and BA 62 rechargeable lithium-ion battery packs. The corresponding charging infrastructure is grouped around six L 6000 charging stations with 22 LM 6062 charging modules for the bodypacks and four LM 6060 modules for the handheld batteries. ‘The charging stations are integrated into the network, which enables us to remotely monitor the capacities of the battery packs being used. The battery life of up to 13 hours is outstanding and more than sufficient for a normal day in our theatre. There is a display that shows the remaining battery life in hours and minutes, and you can absolutely rely on it to be accurate.’

The Digital 6000 wireless systems were supplied by Salzbrenner media: ‘We are really pleased and proud that the Gärtnerplatztheater has been placing its trust in Sennheiser wireless systems for decades,’ says Roland Bachmann (Account Manager Pro AV). ‘By installing the ground-breaking Digital 6000 systems, the Gärtnerplatztheater is excellently equipped for the most demanding sound requirements and has systems that are future-proof.’

Buttgereit is more than satisfied with the Digital 6000 systems: ‘Noise is not an issue at all with digital transmission and, because the channels have no intermodulation, there’s no problem in equipping the main actors with two bodypack transmitters and two headsets during performances. This regularly occurs at our theatre to ensure secure transmission, and our costume department has even made special straps with pockets to hold the SK 6212. The Digital 6000 systems provide excellent sound, and after our decades of positive experience with wireless systems from Sennheiser, we wouldn’t have expected anything else.’