The Advantage of Digital Wireless Systems

Users of wireless microphone and in-ear monitor systems have faced several disruptive challenges in recent years. From the Digital Dividend to the ongoing development of 4G/LTE networks, all have led to uncertainties. Most recently, OfCom added fuel to the fire by announcing its intentions to clear the 700MHz band as early as 2020. Needless to say, these changes continue to have enormous implications for wireless microphone users, and subsequently, you need to select your system carefully.

One way to address some of the challenges of an increasingly uncertain future for RF is to select a digital wireless system. In addition to their transparent sound quality, digital wireless systems offer a number of advantages.

Key Benefits of Digital Wireless Technology

Crystal Clear Audio Quality

Digital systems can deliver a flat frequency response across the entire audible range, meaning the capsule’s sound is not affected by the wireless components in the same way as an analogue system might be. Digital wireless systems convert analogue audio to a digital signal that modulates a radio carrier in discrete steps (ones and zeroes). The result is a digital audio signal that arrives at the receiver unaffected by the radio link. Also, any RF noise below a certain threshold doesn’t affect audio quality. Instead, the audio is always crystal clear without any added noise.
 

Longer Battery Life

Digital wireless microphone systems have 30–40% longer battery life than equivalent analogue systems. For example, the Shure digital ULX-D transmitters run up to 11 hours on two AA alkaline batteries and more than 12 hours with the Shure SB900 Lithium-ion Rechargeable Battery.

Superior Spectral Efficiency

As briefly touched on at the beginning of this article, the amount of clear spectrum available to users of wireless systems has been significantly reduced in recent years. While greater efficiency isn't necessarily true of all digital wireless systems, the modulation type chosen by the manufacturer can potentially lead to much higher channel counts, as explained below:

Higher channel counts are possible because the deviation of a digital wireless signal is more predictable than that of a frequency-modulated analogue signal, allowing tighter channel-to-channel frequency spacing. Depending on the manufacturer and model, digital systems can often deliver nearly twice the channels in the same slice of spectrum as their analogue counterparts. This feature can be worth its weight in gold when facing an increasingly crowded RF environment.

High-Density Mode with Shure ULX-D

Some systems, such as Shure's ULX-D, take spectral efficiency to a new level with High Density Mode. This unique mode further reduces the required space between active transmitters and permits for 63 wireless microphones to work in only 8MHz! This type of usage is incredibly valuable in installations or events that require a huge number of wireless channels across a larger venue, where they are not used in a single space.
 

Understanding Latency in Digital Wireless Systems

Latency is commonly regarded as the main disadvantage of digital wireless. Latency is the amount of time it takes for a signal to arrive at the output after entering the input of a digital device. While high latency can be problematic, most high-quality digital systems have a latency of less than 5 milliseconds, which is acceptable to most listeners. On the contrary, latency is not a factor in analogue equipment, as there is no conversion between analogue and digital.
 

Choosing the Right Shure Digital Wireless Solution

Changes to the RF spectrum have come thick and fast in recent years. Wireless microphone and in-ear users have been significantly affected by changes resulting from the switchover to digital TV and the subsequent expansion of mobile broadband services. 

Alternatively, for help choosing the right Shure Digital wireless system for your application, check out our How to Choose the Right Wireless Microphone System guide.