Mr. Hartmann’s way to deal with changing frequency spectrum

Rocking all over the world – despite the Digital Dividend!


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No matter whether you’re working in the USA, Australia, the UK, France or Germany, all around the globe, as mobile communications technologies (e.g. LTE) continue to spread, there are fewer and fewer radio frequencies available for wireless microphones. Horst Hartmann, who works as a monitor mixer all over the world with stars such as P!NK and Anastacia, deals with this challenge by using wireless solutions from Sennheiser.

  • Author: Frank Schmitt

“We won’t be going back to fully wired microphone setups,” says Horst Hartmann without hesitation. “Events in the form to which we have grown accustomed are only possible because many audio signals can be transmitted wirelessly. Apart from rock and pop productions, that also applies to musicals and broadcasts, of course, where cables are simply out of the question these days. The shows, likewise the expectations of audiences, have grown with the technology and around the technology.


It’s no surprise to hear that times are not easy for musicians, singers and other users of wireless microphones. This is because all over the world, the frequency ranges available for the wireless transmission of audio signals are limited. The appetites of mobile communications providers are insatiable when it comes to frequencies, and that means events have to make do with an ever smaller range of the spectrum.

Horst Hartmann is confronted with the effects of this trend every day. The monitor engineer based in Hannover in northern Germany has worked with big international names such as P!NK, Cher, Anastacia and Sade as well as well-known German performers such as the Scorpions, Die Toten Hosen, Kraftwerk and Nena in his long career. Sound expert Hartmann has been working successfully in this field since 1987. He knows just how important it is to have responsive frequency management and visionary products with the ultimate sound backed up by profound expertise. “Many artists are not necessarily fully conversant with the technology they use. And in my view it is not necessary for them to be so – that’s quite clearly the job of the sound engineer!”

Hartmann begins his day with a frequency scan. “Using an HF analyser and a laptop, I study the frequency spectrum exactly and afterwards set intermodulation-free frequencies with the help of the Sennheiser WSM software. The innovative Wireless System Manager is a very useful tool, especially when wireless components are located in different positions during a show.”

Horst Hartmann
„So far, Sennheiser’s support has always worked very well in all countries.“
„Working with sound icons such as the Sennheiser SKM 5200-II ensures a stress-free situation.“

He tells us that every country has a different system: “In England every town is assigned certain frequencies, and you have to keep to those. In Germany, on the other hand, a defined spectrum is available, and it is the sound engineer’s job to decide which frequencies to use within a given range. In the USA the rules are quite simple. Certain ranges are reserved for LTE or other purposes and they may not be used. However, all other frequency ranges are essentially available. In the United States we can work with an output power of 100 mW, whereas 50 mW is customary in Europe. But only 10 mW is allowed in Japan, which to my way of thinking is really not much at all.”

Throughout the world, besides LTE, the transmission of digital television signals is another reason for the ever smaller frequency ranges available for events. According to Horst Hartmann, “In Germany the nationwide introduction of DVB-T2 is a major topic at the moment. Internationally, too, digital television cannot be ignored. In Italy and England, I was faced with interference from TV channels recently, and digital television is also on the agenda in the USA.” Audio specialist Sennheiser is one place where Hartmann can count on competent support. Hartmann is satisfied: “So far, Sennheiser’s support has always worked very well in all countries.”

When working on major productions, he takes his own wireless setup along. “If I’ve got a groundbreaking receiver such as the Sennheiser EM 3732-II with me, then thanks to a switching bandwidth of up to 184 MHz, I’m on the safe side anywhere in the world,” is how Hartmann sums up his experience. Many top stars work with personalised microphones that attract attention due to their spectacular appearance. Hartmann knows: “Working with sound icons such as the Sennheiser SKM 5200-II ensures a stress-free situation. Owing to the huge switching bandwidth, it is possible to hire a suitable receiver anywhere in the world.”

“All over the world, the frequency ranges that can be used are becoming ever narrower.” But Hartmann is convinced that “in the medium-term, UHF is the best range for wireless audio signal transmissions for professional events”. He continues: “Products with a larger switching bandwidth are without doubt a good choice for worldwide applications, and in the UHF range we will certainly be using the 500 MHz band for a long time to come.”

For musicians, Sennheiser already has future-proof innovative wireless microphone solutions with extremely attractive price/performance ratios in the shape of the evolution wireless G3-1G8, evolution wireless D1 and others. And of course, even for those Sennheiser products that do not operate in the UHF range, a perfect performance and first-class sound are guaranteed!

Die Toten Hosen