It’s about time: Sennheiser Spectera offers step change in digital wireless technology

(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 lavalier, headset microphone or instrument cable, while its 3.5mm headphone jack connects to Sennheiser’s range of professional in-ear phones.

The DAD antenna manages mic/line signals, IEM signals and control data at the same time. Its integrated RF components eliminate the need for additional dedicated RF gear such as combiners, splitters or boosters, and it uses more cost effective and rugged RJ45 connector and CAT5e cables instead of a BNC and coaxial connection to the base station.

Finally, Spectera’s LinkDesk software allows the operator to choose between Audio Link Modes with varying levels of audio quality, latency, possible audio links and range, as well as fully remote control and monitor the entire system.

The start of something bigger

Combined, the system builds on its connectivity and bidirectional abilities, an aspect that Sennheiser’s category market manager Theresa Vondran says makes the Spectera ecosystem unique and promises to be the start of something even bigger.

“Spectera is an ecosystem which is easy to configure, and it also offers time-saving digital workflows,” she says. “It is the first of its kind. Our software provides full remote control and monitoring capabilities over all connectors and system devices to control latency and settings, as well as monitoring RF health and battery status. Its unique modulation and multiplexing capabilities means Spectera is fortified against RF dropouts and interference, plus it offers full system redundancy not just from its dual supply power supplies but from redundant Dante audio connectivity and four assignable antenna ports.

“This is just the beginning; Spectera is a constantly evolving ecosystem, and we will further release services, hardware, functions and features over time.”

The company says it is already working on an SKM handheld transmitter, but Andreas Sennheiser says Spectera will also open up many new opportunities: “3D immersive audio is one such opportunity,” he says. “Thanks to its synchronised word clock for all audio over RF, Spectera will be the first solution that is able to capture phase-coherent wireless audio for immersive recording and reproduction.

“But the platform doesn’t need to know what the users’ future needs are, and we don’t need to foresee what its requirements will be. It’s like not knowing what iPhone app you will be using on a daily basis in the future but knowing that the hardware will be able to support it. The beauty of this system is that it can evolve with user’s upcoming needs; if it needs a new piece of hardware then we’ll work on a new piece of hardware. If it requires a new software feature or a new workflow, we’ll work on that.”

Customer feedback

This is the next stage in Spectera’s development. As an industry tool aiming to simplify the wireless technologies that have historically been so complicated, the company aims to collaborate with the wider industry to ascertain system performance, usage scenarios and future updates.

Volker Schmitt is Sennheiser’s director of product lifecycle management, professional systems. He says: “The interesting thing is that this development is totally new for us as well as for our customers. It is a completely different workflow, and it is designed to develop. It allows us to adapt to new things as we go forward, and so it is vital we work with our customers to find out how best to develop it to meet their needs.

“After the launch event we wanted people to wake up and ask how they can drive this forward. What does the customer need, and what do they need from us to achieve it? At this stage this is pretty complex because customers don’t know what they don’t know.”

Sennheiser is hoping that its announcement at IBC, and developing work with its customers, will encourage a bit more education as Spectera develops.