When the first LTE smartphones were unveiled in autumn 2012 they caused quite a stir among audio engineers. According to the standard for the new handsets, they would transmit at 1800 MHz, a band which is also used by 1G8 wireless microphones. Would, the engineers wondered, conflicts occur with mics and – in the worst-case scenario – could interference be audible on a PA system instead of a singer’s voice? Such fears are fortunately unfounded: Within LTE, there is a five megahertz clearance distance between the uplink/downlink of the mobile radio applications and the band that wireless microphones work in. Even so, it is worth taking a closer look at the spectrum around 1800 MHz, part of which has been allocated to wireless audio transmission in many countries across Europe.
Over the last few months, the first mobile networks based on the LTE (Long Term Evolution) standard have started going live, heralding the dawn of 4G, the fourth mobile radio generation. When the first LTE1800 transmitters were put into operation, they only used a bandwidth of 15 MHz between 1805 and 1820 MHz. Since then, however, many transmitters have been converted to a bandwidth of 20 MHz and also use the frequencies from 1820 to 1825 MHz. Between the frequency ranges used by LTE, the regulatory authorities of many European countries have allocated a range where wireless microphones can be used, in some countries even without a license.
evolution wireless ew 100 G3-1G8
In 2011, Sennheiser was the first manufacturer to launch microphone systems that are able to operate in this range. The evolution wireless ew 100 G3-1G8 series systems work between 1785 and 1800 megahertz; there is a clearance distance of five megahertz to the downlink and uplink ranges of LTE transmitters to ensure that transmission is interference-free.
“With the 1800 MHz systems, we are relieving the burden on the UHF range,” explained Martin Fischer, Product Manager at Sennheiser. “The frequency band from 1785 MHz to 1800 MHz is reserved exclusively for audio transmission, which means that users no longer have to plan their systems around primary users or painstakingly search for gaps between TV channels. In addition, the band is unlicensed in some European countries, so there are no follow-up costs for the user.”
The ew 100 G3-1G8 series enables up to twelve channels to be operated simultaneously. 12 compatible frequency presets are stored in each of the 20 channel banks, with the addition of a further user bank that is freely programmable in 10-kHz steps. The new systems have an RF transmission power of 10 mW; their range corresponds approximately to that of UHF systems with the same RF transmission power.
User-friendliness is a key feature of Sennheiser’s 1800 MHz systems. The transmitters can be conveniently synchronised with the receivers via an infrared interface, and the systems have an integrated equaliser and a soundcheck mode that continuously checks the RF and audio levels. To protect the environment and to minimise costs, both the bodypack transmitter and the handheld transmitter can be powered by Sennheiser accupacks instead of standard batteries; the battery’s state of charge is reliably displayed in four steps.
The 1G8 solutions from Sennheiser are used successfully in a wide range of areas: schools, churches and universities rely on the frequency range between 1785 and 1800 megahertz just as much as bands and PA rental companies do.
As an example, in the summer of 2012, Aida, the musical written by Elton John and Tim Rice, was performed at the University of Erlangen-Nuremberg with 23 sold-out evening performances. Sennheiser ew 100 G3-1G8 microphone systems provided perfect sound for the ancient Egyptian love triangle drama to unfold. The set-up included a 19” rack with 12 ew 172 G3-1G8-type receivers, joined by two ASA 1-1G8 splitters suitable for the 1G8 frequency range, which were connected to a total of four passive AD 1800 directional antennas via AB 3-1G8 boosters. The antennas not only covered the 21 metre-wide stage, but also provided a reliable transmission during the first scene in which the actors moved from the back through the audience towards the podium. Event technician Christian Rheinfelder, responsible for the audio, was enthusiastic about the “set & forget” set-up of the wireless system: “The whole set worked completely stress-free. Despite the numerous wireless networks found on campus, I couldn’t make out any noise interference while it was operating!”
With no permanent venue and around 200 performances during the three-month carnival season, the Cologne music group Kasalla requires maximum flexibility. From 11 November 2012 to Ash Wednesday 2013, Kasalla toured with ew 100 G3-1G8 microphone systems and provided the music in up to eight different festival halls per night. Both people and equipment are pushed to the limit by clocking up so many appearances, yet, even amongst the wildest, craziest goings-on, the Sennheiser systems proved the reliability of their RF transmission. In sound comparisons, the 1G8 systems also know how to convince, according to the experienced sound technician Roland Peiffers: “You perceive no difference to what you expect from the ew 100 G3 systems – just the famous Sennheiser quality!”
Sobre a Sennheiser
Moldando o futuro do áudio e criando experiências sonoras únicas para os clientes - esse objetivo une os funcionários e parceiros da Sennheiser em todo o mundo. Fundada em 1945, a Sennheiser é um dos principais fabricantes mundiais de fones de ouvido, microfones e sistemas de transmissão sem fio. Com 21 subsidiárias de vendas e parceiros comerciais de longa data, a empresa atua em mais de 50 países e opera suas próprias instalações de produção na Alemanha, Irlanda, Romênia e EUA. Desde 2013, a Sennheiser é gerenciada por Daniel Sennheiser e pelo Dr. Andreas Sennheiser, a terceira geração da família a administrar a empresa. Em 2017, o Grupo Sennheiser gerou faturamento de 667,7 milhões de euros.