This article originally appeared in the August 2017 issue of Pro Sound News. Innovations is a monthly column where different pro audio manufacturers are invited to discuss the thought process behind creating their products of note.
Axient Digital is Shure’s next-generation solution for the demanding world of professional wireless microphone systems, designed to thrive under the most difficult conditions. The system literally has so many innovations and new patents that space does not permit the level of detail I’d like to provide.
In essence, Axient Digital comprises two sets of transmitters, AD and ADX, and one digital receiver platform. All components have identically outstanding RF performance and studio reference sound quality, and are tunable across 184 MHz of the UHF band (U.S. version), eliminating the need to match “bands” to different cities. The premium ADX models incorporate the proven Show-Link system, enabling full remote control.
It was a complex assignment essentially replacing two industry-standard systems (UHF-R and original Axient) with a single platform that would earn the trust of the most demanding users. Key goals for the design team included maximizing channel count and flawless operation under adverse conditions. We also wanted to keep or upgrade Axient’s advanced functionality, including frequency diversity, interference detection and avoidance, remote control, and advanced spectrum management—all within a networkable, scalable architecture. Fortunately, Shure engineers live for this kind of challenge.
One decision was relatively simple: moving to the digital domain. Digital wireless eliminates the companding and frequency limitations of analog, resulting in beautifully transparent “like a wire” audio. It’s also more spectrally efficient, with the potential to operate above today’s higher noise RF floor. But decisions have consequences, and going digital meant solving a host of challenges.
One of the biggest was to improve the outstanding RF performance of our industry-standard analog systems in a digital framework. To do that, Shure engineers created an all-new digital radio system, perhaps the crown jewel among Axient Digital’s many innovations. It features a proprietary modulation approach, creating higher sensitivity. To further maximize its effectiveness, the receiver uses the data from both the A and B antennas, combining them intelligently and coherently, rather than merely switching.
Together, these features create more effective RF gain, which translates into greater range while allowing operation above today’s higher noise floors. Precision filtering enables 17 wireless channels in a single 6 MHz TV channel. In addition, Axient Digital offers HD (high density) mode, which can squeeze an amazing 47 channels into a 6 MHz sliver of bandwidth. Despite operating at just 2 mW, HD Mode has an operating range roughly on par with UHF-R. So if you show up at a gig needing 47 channels only to learn that you have just 6 MHz of spectrum available, Axient Digital can deliver.
Another key issue was latency. Translating audio from analog to digital and back takes time. Take too long and the delay starts affecting the performers. With considerable latency already inherent in the modern signal chain from digital consoles, software plug-ins and other sources, it was critical to provide end-to-end audio in under 3 milliseconds. Axient Digital sets a new latency standard for digital wireless, with an amazing latency of just 2.06 milliseconds in standard mode (2.9 in HD).
Another driver of our product development process is user input. While Axient Digital system was a long-term project driven by shrinking spectrum, we know that a big key to successful design is addressing real-world needs. So we consulted with a wide range of power users, including performers, production personnel, rental companies, sound engineers and RF system designers. Their input drove us to even greater innovation.
For large events, system designers need to cover multiple zones and long distances with intricate antenna systems, often requiring real-time tuning adjustments. We found a way to make their job easier. We call it Quadversity.
Axient Digital receivers have four antenna ports: two diversity inputs and two cascade outputs. In Quadversity mode, the outputs become additional inputs, allowing the use of up to four antennas. Thus, by setting up antennas at the four corners of the coverage area, maintaining line-of-sight between transmitters and receiver is virtually guaranteed. Alternately, two antennas can be used conventionally while two more are positioned to cover a separate area, such as a remote stage. Quadversity gives RF system designers a new creative tool that provides tangible benefits while improving workflow.
User input also convinced us to pay extra attention to the issue of sweat and water protection in bodypacks. Whether outdoors in the summer, under the hot lights of a TV studio or hidden inside a theater costume, no piece of wireless gear is at greater risk from liquids. We addressed this by creating the first professional bodypack transmitters with an IP Code, also known as an Ingress Protection Marking (IEC standard 60529), to certify its level of waterproofing.
Where we really went to school was the all-new ADX1M micro-bodypack, designed for high-profile situations like theater. Along with size, we also addressed the inconvenience of external antennas, and user discomfort from the hard edges and high temperatures.
The ADX1M is tiny (60×68 mm, under 3 oz. with battery), but jam-packed with advanced technology. The first thing you’ll notice is the rounded shape, and the lack of the usual whip antenna. Hard corners tend to poke the wearer uncomfortably, and antennas are a nightmare to hide. So we got rid of all that.
We also learned that performers can be distracted by a hot bodypack, especially one attached to sensitive areas of the body. Our solution is ULTEM, a very robust and thermally efficient plastic. So while a metal bodypack transfers heat to the outer case, the ADX1M stays cool. There’s a lot more to it than that, including efficient, cooler-running electronics, but the key point is that heat doesn’t get transferred, so our customers stay cool.
Our goal was to produce a product line that would exceed customer expectations, solving known problems while anticipating future needs. Axient Digital is an incredibly innovative product line that personifies how Shure combined market knowledge, advanced technology, and creative engineering to produce the most advanced professional wireless system on the planet.
Michael Johns is product manager, Shure Inc.