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Wireless Microphones: A Comprehensive Guide

How many time have you wished your wired headphones/power tool/hair clipper/you name it was actually wireless?

A buncha I bet, right? And if you use microphones often, or in certain situations, you might actually need them to be wireless.

Now, when a newbie starts looking at wireless mics, he usually faces these 2 issues:

  • The type of mic – there isn’t just one type of wireless microphone, so how do you actually know which one is the right for your needs?
  • The technology – there isn’t just one wireless technology either, so – again – how do you know which one suits your needs?

And since a wireless microphone is a pretty complex piece of gear, it’s easy to get overwhelmed by the amount of information.

Fortunately there actually are a lot of common elements between wireless mics.

So whether you need to make a presentation in front of a crowd, perform a choreography while singing, drum while singing or even sing while singing (…), I’ve compiled for today’s post everything you need to know about wireless mics.

Sounds good? Then let’s start.

Note: I won’t be covering instrument microphones in this article, only vocal microphone.

Now, before we start going through all the details and features of wireless microphone systems, why not start with some basic rules?

And so…

The 3 Components of Wireless Mic Systems

Whatever the type of wireless microphone, it will always be comprised of these 3 elements:

  1. The microphone itself – there are 3 main types of wireless mics
  2. A transmitter – which receives the signals from the mic an then sends it to the…
  3. A receiver – which sends the signal to the PA system

So let’s look into each of these with more details, shall we?

Starting with…

1. Microphones

There are three types of wireless microphones:

  1. Handheld – which are typically used by lead singers in bands or in situations where there is only one mic and it needs to be passed around
  2. Lavalier – which are the smallest of all mics and are easy to hide
  3. Headset – wich are typically used by live presenters/fitness instructor/pastor microphone as — on top of allowing to keep your hands free — they allow for more movement than Lavaliers that are over-sensitive to surrounding noises.

So let’s look into each of these options with more details, starting with:

Handheld Microphones

Sporting a construction literally anyone is familiar with, handheld wireless mics are generally used in settings where the priority is to be heard, rather than it being the sound quality…

In other words, you’ll find them in loud environments mostly such as concerts.

A lot of speakers do actually use handheld mics too because it may be part of their “show”, some people are simply more comfortable holding the mic…

Rather than not knowing what to do with your hands in the case of an attaced mic.

So if your intent is to capture sound in a quiet room — such as your home office or studio — you’ll probably want to look at the next 2 options.

And so next up…

Lavalier Microphones

Contrary to handheld mics which are dynamic, Lavaliers are condenser mics.

In other words they produce a much more accurate sound…

But are also much more prone to clothes rustle noises.

So if the subject to mic up is likely to move a lot, Lavaliers might not be what you’re looking for.

On the other hand, some companies now sell their LAVs with an attachment that allow you to use your LAV mic as a headset.

Now, Lavalier mics are the smallest wireless mics available and they’re very low-profile, which might be an important factor epending on the ocntext.

And for the final type of wireless microphones…

Headsets

Particularly popular with live presenters, fitness instructors, pastors or singing drummers who need their hands free and move a lot, headsets allow for the greatest freedom of movements.

The major drawback is that they’re much bigger and more visible than Lavaliers.

BUT in terms of ease of use and particularly ease of setting up by sound technicians, they are better in pretty much every way:

  • They offer greater gain before feedback – Headsets stand closer the mouth, meaning they don’t need to be gained as hard as a LAV since the source is closer.
  • They’re design to be driven harder than LAVs – meaning they don’t pick up low-level sounds such as your clothes or what’s coming out of the PA
  • Some model are pretty low-profile – Of course you can’t hide them completely like a Lavalier but between matching skin-color and an ever-shrinking size, modern wireless headset mics are pretty discreet.

All in all, if you’re looking for a mic that can take a lot of moving around, a headset mic is pretty much your best bet.

Next up…

2. Transmitters

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The role of the transmitter is to convert the audio signal picked up by the microphone into a radio signal in order to send it to the receiver.

There are two types of transmitters:

  • Handheld – these are only found in, well, handheld mics, which is pretty convenient since you don’t need a separate device near/on you.
  • Bodypack – This type of transmitter is found on Lavaliers and headsets, since these mics are too small to fit the receiver into them. As its name suggests you’ll need to keep it on you since it is hooked up to your mic.

Handheld transmitters are only available when built into handheld mics…

Whereas bodypack-type transmitters are used with Lavaliers and headsets microphones.

Now, although you generally don’t get to decide which transmitters your mics comes with, since they wireless mics are generally sold as an all included bundle…

There still are some important differences between cheap transmitters and high-end transmitters, such as:

  • An auto-scan feature – the transmitter looks for the best frequency alone, so you don’t have to do it yourself — which can be tedious
  • The frequencies it works on – Probably the most important factor to consider, cheap mics ans transmitters only work on “busy” freaqencies used by cellphones and wi-fi networks. In other words you are almost guaranteed to have signal cutouts/dropouts when using these cheap wireless mics.

Next up…

3. Receivers

Receivers are the final step before picked up sound is amplified and heard by the audience.

There are a few major factors to take into consideration when choosing a receiver:

  • Diversity Circuitry – Probably the most important factor to consider,
  • Frequency Agility – which refers to the ability of the receiver to auto select the best frequency
  • Display – A display will keep you informed of the receiver’s status, so get a receiver with one if you can afford it.
  • Encrypted transmission – some higher-end systems offer full encryption in the signal, so that even if somebody manages to intercept it, they won’t be able to read it.

So let’s look into these characteristics into more details, shall we?

Starting with…

Diversity Circuitry

Diversity of a receiver refers to how well it can receive a radio signal, and how well it can avoid signal dropouts.

There are 3 types of diversity:

  1. Non-Diversity – which means the transmitter only has one antenna and one radio receiver
  2. Diversity  which means the transmitter has 2 physical antennas but only one radio receiver
  3. True-Diversity – which means the transmitter has 2 physical antennas and 2 radio receivers

So how does the type of diversity helps reduce dropouts and improve signal reception? Well, by constantly monitoring this very signal reception.

In case of diversity or true-diversity receivers, the signal is monitored and the one with the better quality is chosen in order to deliver the best sound possible.

Now, true-diversity wireless systems are obviously pricier, which is why you can still find non-diversity or diversity receivers.

How do you that? By analyzing the place you will be in when using the wireless system and asking yourself these questions:

  • Is it a large venue?
  • Does it have a lot of objects or furniture inside?
  • Will there be a lot of interference?
  • Is the distance between the presenter and the receiver significant?

If you answered YES to at least one of these questions, get yourself a true-diversity receiver.

And if you didn’t… get yourself a true-diversity system ANYWAY, at least if you can afford it.

Because it will ALWAYS be the better choice.

Next up…

Frequency-agile vs. Fixed-frequency 

While browsing wireless mic systems you’ll often find “freauency-agile” in the description.

A frequency-agile system is a system that automatically finds the best freauency to operate on, whereas a fixed-frequency system always stays on the preset freauency.

In other words if you’re planing on leaving your wireless system in the same venue all the time then a fixed-frequency setup might be enough.

However, if you’re planning on taking your wireless system from one place another, a freauency-agile receiver is virtually imperative.

Next up…

Why You Shouldn’t Mix and Match Components

Many wireless systems use a process called companding that…

Compresses the transmitted audio signal at the microphone then expands it at the receiver to restore the dynamic range of the audio.

This is done to deal with the limited capacity of wireless channels. Other circuitry is used to detect and remove noise from the transmitted signal.

Because systems from different manufacturers, or even different systems from the same manufacturer, have different methods of companding…

You should avoid mixing components from different systems, even if they use the same frequency.

Got it? Next up…

The 4 Key Features of Wireless Mic Systems

Let’s go over each one of the features that may affect use and quality of the system you’ll eventually choose.

  1. Microphone Polar Patterns
  2. UHF vs VHF
  3. Maximum Operating Distance
  4. Analog vs Digital

Starting with…

1. Wireless Microphone Polar Patterns

A polar pattern is the 3-dimensional space surrounding the capsule where it is MOST sensitive to sound…

The 3 basic patterns are:

  • omnidirectional – which is the polar pattern of most headset mics
  • figure-8 – there are virtually no wireless mics with that polar pattern
  • cardioid / supercardioid / hypercardiod – most handheld and Lavalier mics have a cardioid polar pattern or one of its variation

To learn more about microphone polar patterns, check out this post:

Now the reason I mention polar patterns is because they are actually a major factor to consider when selecting a wireless mic.

Here’s why:

  • Cardioid polar pattern mics – offer more gain before feedback and reject more off-axis sounds. Which is pretty much always a good thing. On the other hand they’re also more prone to pick up plosives, which can easily be fixed by using a windscreen.
  • Omnidirectional polar pattern mics –  or lavs to be more specific pick up sound from every direction, partly because they’re always placed further away from the source. For this reason they tend to pick up clothes rustle, which is why it’s advised to use them in a more static set up.b

The most common patterns you find out there for…

  • Handheld Wireless Mics – are cardioid and supercardioid, while for…
  • Lavalier / Headset Mics – the omnidirectional pattern is most common, since it has equal sensitivity at all angles, meaning it picks up sound from all directions.

Next…

2. UHF vs VHF

Every wireless microphone system transmits and receives on a specific radio frequency, called the operating frequency.

They operate either on the:

  • UHF (Ultra High Frequency)
    • low-band – 450-806 MHz
    • high-band – 900-952 MHz
  • VHF (Very High Frequency)
    • low-band – 49-108 MHz

Allocation and regulation of these frequencies is supervised by specific government agencies in each country in order to promote efficient use and gain a net social benefit.

In the US, their use is regulated by the Federal Communication Commission (FCC) and you can find which frequency you are allowed to use with this tool (US only).

The regulations for users and licensing are essentially the same in the VHF and UHF bands, though.

Certain frequencies within each band have been designated for use by wireless microphones as well as by other services.

Keep in mind that, because of the regulations, wireless microphones operating in the 617-652 and 663-698MHz are “illegal” since July 2020.

So, let’s start with…

VHF

And this is exactly what may happen if you choose to pick a VHF wireless mic system, which are considered entry-level.

Here’s why:

At the beginning of the low-band VHF range is the 49 MHz region.

It is used not only by inexpensive wireless microphones, but also by:

  • cordless telephones…
  • walkie-talkies, and…
  • radio controlled toys.

So, due to the large number of users, and high levels of general radio frequency (RF) “noise,”…

This band is more prone to interference from many sources and dropouts.

Also, the minimum proper antenna size for units in this range can be over three feet long (1/4 wavelength), what can severely limit portability and/or efficiency.

Bottom line, use this type of wireless systems if you:

  • Won’t use them professionally
  • Use less than 4 mic systems at the same time
  • Perform/speak in open radio environments, free of interference
  • Don’t have a line of sight between transmitter and receiver
  • Have really limited budget

Following…

UHF

uhf wireless microphone systemLike the VHF region, the UHF region contains several bands that are used for wireless microphone systems.

However…

UHF bands are used by higher-end systems, because…

They have more transmitter range and are less prone to interference from other electronic and digital devices.

Their other pros are:

  • Clearer, professional-quality sound – which is essential for a professional use
  • Less dropouts – which allows you to move further away from the transmitter without jeopardizing sound quality

Their cons are:

  • They require more power – since they generate higher-energy waves
  • They are more expensive – higher quality, higher cost

In a nutshell, pick a UFH mic system if you:

  • Need 4+ channels
  • Use it in areas of interference
  • Require line-of-sight

Up next…

3. Maximum Operating Distance

Now, if you plan on moving around a big stage or auditorium, you’ll want to know some detail about your system.

It is imperative that the receiver pick up a “useable” signal from the transmitter.

Elements that affect usability are:

  • Transmitter Quality
  • Receiver Quality
  • Interfering objects between transmitter and receiver
  • Radio-Frequency Interference

Losses are generally frequency dependent: the higher the frequency, the greater the loss.

Rather than quoting a specific maximum operating distance, most manufacturers of wireless microphone systems give a “typical” range.

  • For lower quality systems – you can expect a range of as low as 100 ft.
  • With higher quality systems – expect a range as high as 1000 ft.

However, a good rule of thumb is choosing a wireless system with a stated operating range twice the distance you think you need.

Up next…

4. Analog vs. Digital Systems

Digital wireless systems convert audio to a digital signal before sending it through the air.

High-quality 24-bit digital wireless systems deliver extremely clear audio, with a wider dynamic range than traditional analog systems.

However, since most entry-level digital systems run on the 2.4 GHz band, they offer potentially fewer simultaneous compatible channels.

Analog wireless systems are still the most cost-effective choice if your channel count is in the double digits.

High-end, expensive digital wireless systems, which typically run on the 900 MHz or UHF band, offer the best of both worlds — superb audio quality, plus high channel counts.

More about digital audio in my article:

Next up…

Recommended Models

Now that you know what type to use in what situation, let’s check out the best models currently available.

I ordered this list by form-factor:

  1. Handheld
  2. Lavalier
  3. Headsets

And so, first off:

Handheld

Lavalier

Headset

And That’s It

So there you have it, The Ultimate Guide to Wireless Microphones.

Hopefully you’ve found everything you were looking for!

‘Til next time.