It's about time: Sennheiser Spectera offers step change in digital wireless technology By Kevin Emmott Monday, September 23, 2024 - 10:42
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(L-R): Sennheiser's Vice President Sales EMEA Christophe Van Den Berghe, Category Market Manager Theresa Vondran and CEO Andreas Sennheiser at the Spectera launch event
It's been almost 70 years since Fritz Sennheiser invented the world's first ever wireless microphone in 1957, and wireless audio technology has worked pretty much the same way ever since. So, when Sennheiser unveiled a spectacular new way of managing wireless signals at a glitzy launch event at De Hallen Studio's in Amsterdam during IBC2024, you would be forgiven for thinking it's about time.
And you'd be right, in more ways than one.
Sennheiser says Spectera is the world's first wideband, bidirectional, digital wireless ecosystem and it is literally all about time. Not just the 11 years Sennheiser has been developing the idea of managing wireless signals with broadband technology, or the six years it has spent lobbying the FCC, or the 18 months of dedicated development since the company first announced its Wireless Multi-Channel Audio System (WMAS) technology in March 2023.
Time is Spectera's defining feature because it is central to its technology.
Introduced on stage by CEO Andreas Sennheiser, Spectera represents a step change in digital wireless technology. Using Sennheiser's WMAS technology, Spectera does a whole bunch of stuff. It reduces wireless system complexity, it increases capability, it simplifies setup, and it does all this with way less equipment. It delivers full remote control and monitoring (including permanent spectrum sensing); it is highly resistant to RF fading; and its compact bidirectional bodypacks deal with digital IEM/IFB and mic/line signals as well as control data simultaneously, and in the same wideband RF channel.
Oh, and its base station can handle up to 64 wireless audio links (32 in/32 out) in just 1U of space.
Challenges
It's a lot, so it's no surprise that Andreas Sennheiser admits that it was a challenging development.
There's not a single challenge there but a multitude of challenges that you have to overcome in order to create a system that's really compelling, he says. Whether that's working with the authorities on regulations for the use of the RF broadband spectrum, the development of a brand-new transmission scheme, or the software integration. There are so many moving parts that we had to totally rethink.
It's the first time in 65 years that we're not just transmitting on one carrier, and therefore it's right to say that this is a new era in wireless transmission, but from the beginning we had a system in mind that didn't operate like a transmitter and receiver; we envisioned a system that would make it simpler for the customer to do their job now and be able to evolve in the future to cater for future needs.
A different approach
At the centre of everything is Sennheiser's WMAS, a development which began in 2013 and took many years working alongside the authorities to get adopted. For decades, narrow-band microphones have always stipulated a maximum RF transmission bandwidth of 200kHz, but in 2017 Sennheiser's work with the European Telecommunications Standards Institute (ETSI) resulted in getting WMAS included in EN 300 422-1.
A year later the European Conference of Postal and Telecommunications Administrations (CEPT) removed bandwidth limits from its own recommendations for wireless microphones, and Sennheiser filed a Petition for Rulemaking with the FCC to request a modification in their bandwidth specifications for wireless microphones. This led to the FCC permitting operation of WMAS in the US earlier this year.
Spectera was launched just a few months later.
It's the first time in 65 years that we're not just transmitting on one carrier, and therefore it's right to say that this is a new era in wireless transmission
Instead of using those individual 200kHz narrowband RF carrier frequencies, WMAS uses a single wideband RF channel for the bidirectional transmission of audio and control data; in fact, it uses a TV channel of 6 or 8MHz.
The system coordinates itself by organising every single audio link within this channel, whether it's a mic or an IEM, and every signal is assigned a specific time slot for transmitting its audio information. This makes it possible to have multiple IEMs and mics in the same TV channel instead of two channels separated by a guard band, which makes setup easier by massively simplifying frequency coordination, not to mention the reduction in the amount of kit required to do it, especially for larger productions.
In addition, as every audio link uses the full width of the RF channel when it is its turn to do so, it greatly reduces RF fading as well.
Four areas of development
The system is made up of four main components.
Spectera's Base Station squeezes 32 inputs and 32 outputs in a 1U footprint, and it can accommodate up to two RF wideband channels. It is frequency-agnostic, and activation of the respective local licence automatically loads the authorised frequency ranges. It is also extremely robust with two PSUs, primary and secondary Dante connections, two slots for optional redundant MADI connections, and four antenna ports. These ports not only allow for redundancy, but also for extended, synchronised antenna zone coverage or higher system capacity by using additional frequency ranges.
The system's bodypacks are just as hardworking, handling mic/line and IEM/IFB requirements at the same time; this means less equipment for the talent to carry, and less equipment for the sound crew to store, pack, test and fit. They feature a 3-pin connector for a lavalie
