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Wireless Microphones
How To Choose Wireless Microphones
 


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How wireless microphones work
types of wireless microphones
How to choose a wireless microphone that works for you!


1. How do wireless microphones work?

2. What makes wireless microphones different from each other?

3. How to choose a wireless microphone that works for you!



Wireless DiversityWireless Microphones

In this article we focus on wireless microphones as distinct from wired microphones.

The main advantage of wireless microphones as compared to wired microphones is freedom of movement. With wireless microphones a vocalist or presenter has much greater flexibility to move around a stage or among an audience. The biggest disadvantage is price, as wireless microphones are, in general, more expensive.


How Wireless Microphones Work

Characteristically, wireless microphones require a wireless transmitter, and a wireless receiver.

The wireless transmitter is either built into the microphone itself (as in handheld wireless microphones), or is connected by a short cable to a body pack transmitter (as in handsfree wireless microphones). All wireless transmitters require a battery (typically 9-volt or AA batteries) and broadcast through an internal or external antenna.

The wireless receiver is tuned to the same electromagnetic wavelength as the transmitter (usually VHF, UHF or IR) and is physically attached to an output device such as a PA system or a closed system headset.

 

 


Types of Wireless Microphones

TYPES OF WIRELESS MICROPHONES - Handheld Wireless Microphones vs. Handsfree Wireless Microphones

Handheld wireless microphones are literally held in the hand of a presenter or a vocalist. In this way the microphone can be used as a prop in a performance. Most importantly, the distance between the sound source (e.g. the mouth) and the microphone can be varied with a resultant change in volume and fidelity. This allows for a number of special effects in a performance to emphasize different phrasing. Think Frank Sinatra!

Here's an example of a top drawer vocal microphone from Shure.


Shure Wireless Handheld Microphones

Shure Wireless Handheld Microphones

 
Shure ULXS24/58-SM58 UHF handheld wireless microphone systems include a wireless handheld cardioid microphone with an integrated transmitter, an 8 hour battery life, and an operating range up to 300 feet. This handheld wireless microphone system features Predictive Diversity, which anticipates and avoids sound dropouts. Buy Now This Shure handheld wireless microphone system delivers dependable, frequency-agile performance, along with clear channels and strong transmission. Learn MORE >>
 

Handsfree wireless microphones come in three popular configurations, or if you will sub-categories: lapel (or lavaliere) wireless microphones, collar wireless microphones and headband wireless microphones.

All three types of handsfree wireless microphones, as the name implies, leave the presenter with maximum freedom of movement. This is especially helpful for those who want to talk with their hands (e.g. sign language interpreters), operate multimedia equipment while they speak (i.e. using computers or projectors during presentations), operate heavy equipment (e.g. construction workers) or engage in self-defense or combat (self-explanatory). In addition, handsfree wireless microphones fix the distance between the sound source and the microphone which gives you a consistent volume level; this is especially useful when miking novice speakers in a public setting.

The Anchor Audio UHF 6400 is an example of a wireless microphone which has the option to be bundled with all three types of handsfree options (as well as a handheld wireless microphone).


Anchor Audio Wireless Microphones

Anchor Audio Wireless Microphones

 

The Anchor Audio UHF-6400 wireless microphone system gives you 64 channel true diversity and allows you to choose a microphone suitable to your needs.

AudioLinks offers this system with the option of one of four different configurations:

(1) a handheld microphone with a built-in transmitter;
(2) a handsfree lapel microphone (also called a lavaliere mic) with a bodypack transmitter;
(3) a handsfree headband microphone with a bodypack transmitter; or
(4) a handsfree collar microphone with a bodypack transmitter.

Although made for Anchor Audio PA systems, the Buy NowUHF 6400 microphone system is compatible with virtually any PA system. The Anchor UHF-6400 is an affordable wireless handheld microphone system that is designed for use in presentations, lectures and public events.
Learn MORE >>

 


TYPES OF WIRELESS MICROPHONES - VHF Transmitters vs. UHF Transmitters

VHF TRANSMITTERS

EM Spectrum

All wireless microphones must overcome problems of transmission, especially when interference muddies or blocks a signal from the transmitter to the receiver. Transmission is affected by the wavelength of the signal and the type of antennae used in the receivers (receivers are discussed in the next section below).

The wavelength of the signal in wireless microphones is broadly designated as using radio waves (Radio Frequency or RF) or InfraRed (IR). The former is often called FM wireless and has two distinct ranges of government approved frequencies: VHF (Very High Frequency) and UHF (Ultra High Frequency). We will examine each of these in turn.

VHF (Very High Frequency) radio signals in the range of 49MHz to 216MHz are the least expensive solution to wireless transmission. This is because in the VHF range your transmission works with a single antenna and does not require diversity antennae (discussed below).

The FCC divides VHF into a low band (49MHz to108MHz) and a high band (169MHz to 216MHz). Low band VHF is used by cordless telephones, walkie-talkies, radio controlled toys, television channels 2 through 6, and wireless assistive listening systems.

High band VHF is FCC approved for wireless microphone users. The first part of this high band spectrum, from 169MHz to 172MHz, includes eight specific frequencies, known as low band VHF. These are often referred to as "traveling frequencies" because broadcast television is excluded from them. The primary users of this band include businesses and government operations such as digital paging services, hydroelectric power stations, and the U.S. Coast Guard.

The downside of wireless microphones in this low band VHF range is radio frequency interference (RFI). Although broadcast television is excluded from the low band VHF range, the volume of traffic on these frequencies, and the spacing between them, makes using wireless microphones subject to interference. The interference problem becomes virtually intolerable when using three or more wireless microphones in this range.

The high band VHF range, 169MHz to 216MHz, is designated by the US government for broadcast and commercial film/video production. Within the high band VHF range audio transmission is significantly improved. Interference is less than that of low frequency radio waves. As a result, wireless microphones can be made with manageable antenna sizes that produce good results in almost any part of the US.


Nady VHF 351 Wireless Mic System

Nady VHF 351 Wireless Mic System

 
The Nady VHF 351 VR-HT handheld wireless microphone package operates in the high band VHF range and is widely used to make pro-audio quality commercial videos. This microphone system is convenient, easy to use and Buy Now compatible with virtually all camcorders and video cameras. This microphone system provides 120 dB of dynamic range with minimal background hiss and/or overload distortion. Once you try it , you'll never want to use your camcorder without it. Learn MORE >>
 


UHF TRANSMITTERS

The Ultra High Frequency (UHF) range contains several bands portions of the electromagnetic spectrum from 470MHz to 806MHz that have been set aside by US government for wireless microphone systems.

The shorter wavelength of the UHF radio waves creates higher energy transmissions that punch through interference. Greater bandwidth is allowed for UHF signals (eight times more than the High Band VHF), permitting a larger number of available frequencies without compromising the intervals between frequencies. This allows more systems to operate simultaneously - a significant benefit in complex setups and concert applications. By the way, you can also run both UHF and VHF systems in the same location without mutual interference.

A drawback of the shorter UHF wavelength in wireless microphones is a reduced range for a UHF signal compared to a VHF signal. In addition, UHF transmitters work better when there is a "line-of-sight" between transmitter and receiver operation. Both of these limitations have to do with the way that the shorter wavelengths of the UHF band reflect from small metal objects and move around obstacles such as corners or intervening barriers. The susceptibility of UHF transmitters to interference and dropouts is best addressed by diversity receivers discussed below.

Historically the price differential between the VHF wireless microphones and the UHF wireless microphones was large and made the VHF wireless microphones popular for people with limited budgets. However, it's now possible to purchase basic UHF microphone systems at prices comparable to VHF systems which gives UHF wireless microphones a distinct advantage for pro-audio uses.


Samson UHF Series One Wireless Microphone Packages

Samson UHF Series One Wireless Microphone Packages

 
The Samson SWLSH05 UHF Series One hand held microphone system provides a high performance, cost effective solution, using state of the art wireless technology. The Samson Series One operates in a frequency range from 801MHz to 805MHz and contains six separate channels, all operating in the less crowded UHF bandwidth, and all designed for simultaneous use. Buy NowThis complete hand held microphone system ensures reliable clarity and functioning, making it one of the most popular wireless systems in the world. Learn MORE >>
 


TYPES OF WIRELESS MICROPHONES - Diversity Receivers vs. Non Diversity Receivers

Non-Diversity vs. Diversity Receivers

Quality and performance in wireless microphones depend not only on the type of transmitter, but also on the type of receiver.

Historically when High Band VHF transmitters were the dominant type of wireless system, a relatively simple single antenna was sufficient. But with the greater capability of UHF transmitters a better antenna was needed to take advantage of the greater potential of the system. Thus the birth of the diversity receiver.

Diversity is a reception technique by which two antennae are utilized to eliminate dropouts that occur when multiple signals arrive at the receiver at different times.  A dropout can be the result of a weak signal, causing a hiss, or a lapse in the silencing circuitry, which results in a "pop". A diversity system constantly monitors the antennae to see which is providing the stronger signal at any given moment so that the receiver can utilize the stronger signal.

A true diversity system goes one step further by using two separate receivers housed in a single unit each of which is paired with one of the antennae. Whichever receiver detects the stronger signal is the one that is used.


Shure ULX Diversity Wireless Microphone Packages

Shure ULX Diversity Wireless Microphone Packages

 
The Shure ULXP4 is a half-rack single channel predictive diversity wireless receiver, featured in many of Shure's ULX wireless packages. This Shure diversity receiver has a variety of professional level wireless audio and utility features, including 1400 selectable Buy Nowfrequencies, RF, battery and signal strength indicators, and a frequency lockout function. This diversity receiver can be used with any transmitter in the Shure ULX series. Learn MORE >>
 


TYPES OF MICROPHONES - Radio Frequency vs. Infrared Transmission

For a discussion of Radio Frequency (RF) vs. InfraRed (IR) transmitters see our separate article.


Nady IRW 220X Infrared Wireless Microphone Packages

Nady IRW 220X Infrared Wireless Microphone Packages

 
Nady IRW 220X infrared microphone systems use infrared light transmission technology, and do not transmit through walls, making it possible to use any number of IRW systems in the same building without interference. This advantage makes Nady IR microphone systems an ideal alternative to standard VHF and UHF wireless mic set-ups for a variety of applications. Nady IR microphone systems also provide added Buy Nowsecurity since they do not transmit beyond the room in which they are being used. Learn MORE >>
 


Choosing Among Wireless Microphones

CHOOSING AMONG WIRELESS MICROPHONES - IR Wireless Microphones vs. UHF/VHF Wireless Microphones

Although they are based on different technologies (lightwave vs. radiowave) infrared wireless microphones and UHF/VHF wireless microphones share many similarities. Here are some useful tips:

Consider Infrared if:

•   Privacy or security is necessary
•   You want to eliminate all possibility of interference
•   You will be using many separate, indoor systems in close proximity to one another (schools, conference
     centers, etc.)
   Your program is indoors (infrared may be affected by sunlight)

Consider UHF/VHF if:

•   Privacy or security is not necessary
•   Your program is conducted in "open" radio environments, free of interference
•   You move from indoors to outdoors
•   You do not have line of sight between transmitter and receiver



CHOOSING AMONG WIRELESS MICROPHONES - UHF Transmitters vs. VHF Transmitters

Is UHF always the better choice compared to VHF transmitters? Not necessarily. Your needs and your budget are the deciding factors.

Choose UHF if:

•   You will be using your wireless microphones in various locations
•   You use more than 4 wireless microphones simultaneously with multichannel systems
•   You play in "crowded" VHF radio environments such as large cities and airports
•   You do not have line of sight between transmitter and receiver
•   You're willing and able to spend a little extra

Choose VHF if:

•   You use fewer than 5 systems at the same time
•   You perform in "open" radio environments, free of interference
•   You do not have line of sight between transmitter and receiver
•   Your budget is limited

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You may also wish to read our other product reviews on microphones.

Microphones - See All Microphones
Microphones -
Wired Handheld Microphones
Wireless Microphones -
Wireless Hand held Microphones
Wireless Microphones -
Wireless Hands free Microphones
Wireless Microphones -
Wireless Microphone Packages
Microphones -
Instrument Microphones
Microphones -
Push to Talk & Boundary Microphones

       

 

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