Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now


Innovations: Shure SLX-D Digital Wireless System

Mu Yang, product manager, Shure Global Product Management, traces the development process behind transitioning Shure’s long-running analog-based SLX wireless microphone into the digital realm.

This article originally appeared in the September 2020 issue of Pro Sound News. Innovations is a monthly column in which different pro audio manufacturers are invited to discuss the thought process behind creating their products of note.

Mu Yang headshot
Mu Yang

The recently introduced SLX-D wireless system is a digital reimagining of Shure’s hugely successful analog SLX wireless. The motivation was simple: any technology-based product, such as a wireless microphone, cannot remain competitive without change. After many years of success, it was time.

Since the introduction of SLX in 2004, changes to the wireless landscape have been substantial. Analog has become digital. Features have advanced. The frequency spectrum has changed. These advances required us to do more than simply change from analog to digital. Instead, we took a long look through a specific lens, determining how to best serve the needs of the SLX user base in the context of today’s technology.

The result is SLX-D. Driven by research of specific customer needs and desires, our team was charged with bringing Shure wireless innovations from high-end touring to the average user. SLX-D delivers channel efficiency, high sound quality and ease of use without being loaded down with expensive esoteric features that most customers don’t need. Our typical users include sound companies, houses of worship, performance venues, educational institutions, corporate facilities, local government and more. Creating a system to satisfy such a wide range of clients was essential.

Our four main areas of focus were determined by customer research to be the most important: RF reliability, audio quality, ease of use and battery management. Our goal was to maximize all of these things while holding true to the SLX value proposition.

Dependable RF performance is the most critical aspect of any wireless system. In recent years, the available UHF frequency range has shrunk horribly, with huge swaths of bandwidth no longer available; those that remain are much more crowded than before. Fortunately, Shure engineers have been busy innovating their way around this problem with our high-end systems.

Shure SLX-D product family

Using digital transmission, SLX-D achieves higher channel density than any analog system, with rock-solid RF signal reliability. This maximizes the available frequencies, with the ability to deploy 10 simultaneous systems in just 6 MHz of spectrum—the equivalent of one UHF TV channel. Across its typical 44 MHz tuning range per band, up to 32 systems can be used at the same time. If more systems are needed, the user can access multiple bands. In the United States, SLX-D offers three bands covering the 470 MHz–602 MHz spectrum. Since many SLX-D owners will use 10 systems or fewer, we knew we had the appropriate level of technology.

Superior sound quality was another goal. We wanted to significantly upgrade from analog standards. The engineering team succeeded in delivering a full 20–20,000 Hz signal, with a dynamic range measured at a full 120 dB. The digital audio processing is 24-bit/48 kHz, the output is pure analog, and the system’s total harmonic distortion (THD) is almost unmeasurable—just 0.01 percent—so the SLX-D can accept a very wide range of input sources, from very strong to very weak signals, without requiring gain adjustment on the transmitter. SLX-D is able to gracefully handle a very wide variety of musical instrument inputs, particularly those with fast transient, high crest factor signals, and make them sound clear and well distinguished from each other.

Shure Launches SLX-D Digital Wireless System, Aug. 3, 2020

Of course, with audio, excellence is subjective. To confirm we had achieved sound quality that would turn heads, we took SLX-D on a global tour for listening tests with sound engineers and key integrators. Beta test sites included a mix of nightclubs, theaters, houses of worship and other facilities in 13 nations, including the United States, Japan, India, China, South Korea, UK and Germany. There were A/B tests with comparisons to a facility’s current products. Complex, fast-attack sources like chimes were used—traditionally the most difficult sound for wireless systems. Time after time, SLX-D earned praise for its full, rich, natural sound, with customers often commenting that they did not expect such outstanding audio. It’s something our team is very proud of.

Another challenge was to make it easy for anyone to use the system effectively. This is where SLX-D really shines. When you power up an SLX-D receiver, it literally offers to walk you through the entire system setup process, step by step, all via prompts on its LCD screen. We call it Guided Frequency Setup. This feature can guide the user either to initialize the new system setup, or add additional receivers to the existing systems.

Most modern wireless systems are capable of finding an open frequency. SLX-D can do that for a connected group of receivers. The key is the ability to create a local network, using the Ethernet connector on the back to connect multiple receivers, thereby creating a local SLX-D network. With a few clicks, Group Scan will then find and deploy compatible open frequencies for all of your connected receivers, quickly and automatically.

2020 Marks Shure’s 95th Anniversary, April 23, 2020

It’s worth mentioning that the SLX-D dual receivers are very easy to install on the racks—fewer screws, fewer brackets and less time. The Ethernet port brings additional benefits as well: It allows SLX-D systems to accept future firmware updates from Shure, and enables connection to third-party room control systems like AMX or Crestron. This is obviously a key benefit for installation contractors and designers.

Finally, we addressed battery management. SLX-D transmitters can use both AA and Shure rechargeable batteries. While Shure offers industry-leading smart rechargeable technology, we decided to offer it as an option. Our lithium-ion rechargeable batteries offer the same runtime as the alkalines (8 hours). They also display actual remaining battery life on the transmitter in hh:mm format, so there’s no guesswork. The battery contains a chip that tracks and displays battery statistics like total full charging cycles and battery health. The ecological benefits and long-term cost savings are a given.

A hidden benefit that actually produces additional savings is physical battery management. Users simply slot their transmitter into the dual charging station when done, eliminating the daily task of checking and replacing batteries and making sure transmitters are off. This saves enormously on labor and eliminates downtime—something that any corporation, school campus or worship facility will truly appreciate!

The final goal of our product development process was to stay true to the loyal users of analog SLX, to meet their needs while respecting their budgets. That is why there are no new Shure accessories for SLX-D, other than the optional battery system. Instead, every antenna, every splitter, every antenna distribution system, and every cable already in use can simply be repurposed as part of the new system.

In conclusion, SLX-D succeeds in meeting the four biggest needs for wireless microphone users. It has the fidelity performing musicians demand, the RF reliability to operate in difficult environments,, the ease of use that allows non-technical users to achieve outstanding results, and the ability to incorporate advanced battery management. Advanced digital architecture and customer-driven design make SLX-D a great investment for sound rental houses, a natural choice for installation contractors, and an outstanding creative tool for musicians. The Shure product development team is proud to present SLX-D as the “next generation” of user-friendly professional wireless.

Shure •