The Advantage of Digital Wireless Systems

The Advantage of Digital Wireless Systems

Marc Henshall | February 9, 2015

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

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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 as follows:

Crystal Clear Audio at all times

Digital  systems can transmit a flat frequency response across the entire  audible range, meaning the sound of the capsule is not affected by the  wireless components in the same way 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 that may be present below a  certain threshold doesn't affect the audio quality. Instead, the audio  is always crystal clear without any added noise.

Batteries Last Longer

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.

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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.

Some systems such as Shure's ULX-D, take spectral  efficiency to a completely new level by using 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.

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What Are the Disadvantages of 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 large latency  values could potentially be problematic, most high-quality digital  systems produce less than 5 milliseconds of latency, which is acceptable  to most listeners. On the contrary, latency is not a factor in analogue  equipment as there is no conversion from analogue to digital and back.

Become a Wireless Expert

Changes  to RF spectrum have come thick and fast in recent years. Wireless  microphone and in-ear users have been significantly affected by changes  as a direct result of the switchover to digital TV and the subsequent  expansion of mobile broadband services. Keep up to date with the latest  changes and get your free guide to wireless frequencies in the UK by visiting LosingYourVoice.co.uk

Alternatively, for help choosing the right Shure Digital wireless system for your application, check out our previous post.

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Marc Henshall

Marc forms part of our Pro Audio team at Shure UK and specialises in Digital Marketing. He also holds a BSc First Class Hons Degree in Music Technology. When not at work he enjoys playing the guitar, producing music, and dabbling in DIY (preferably with a good craft beer or two).