Debunking Analog vs. "Digital Wireless" Microphones

"You have to use this antenna or that distro because these new wireless mics are... digital"

You may be confused by all the claims going around as to whether you need different antennas and antenna distribution systems to work with your digital wireless mic system. This is a question we hear all the time, and more so now that new more affordable digital wireless mics are coming on the market. 

In order to prove that let’s take a look at what antennas actually do as a part of your system:

 

Antennas are transducers that change electrical signals into radio waves (RF) or convert radio waves into electrical signals depending on whether you are transmitting or receiving. The same antenna can both transmit or receive, a function known as reciprocity.   This is similar to what other transducers such as microphones and speakers do converting sound waves into electrical signals.

 

RF is part of the electromagnetic spectrum

 

Radio waves are a type of electromagnetic radiation similar to microwaves, infrared, visible light, x-rays and gamma rays.  The primary difference among these types of electromagnetic radiation is their wavelength.  Radio waves are on the lower frequency (longer wavelength) range of these types of radiation.

 

 

RF Venue antennas and antenna distribution systems are compatible with analog and digital wireless mic systems.  Shown here: Audio-Technica 3000 series analog, Sennheiser EW-D and Shure SLXD series digital wireless

So here's where everybody gets confused:

  

 

Strictly speaking there is no such thing as “digital wireless" 

 

1.  All wireless microphone systems broadcast using a transmitter 
    that generates an analog RF carrier wave   

2.  The method of transmission is the same for analog and “digital wireless" mics
    in that they add the audio signal to the carrier wave by modulating it 

3.  It is the specific method of this modulation that creates an “analog” or a
    “digital” wireless mic in marketing terms

“Analog” wireless mics use FM modulation so the width of the transmitted wave varies according to the frequency and intensity of the signal being imposed on it.  To somewhat simplify, “digital” encoding of the carrier imposes pulses onto the carrier (ones and zeros) and then decodes that on the receiving end to create audio.  There are other benefits to this approach, such as digital AES encryption of a wireless mic, and narrower carrier frequencies to squeeze more channels into less RF spectrum.