Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems...

16
A Shure Educational Publication Wireless Microphone Systems Introduction

Transcript of Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems...

Page 1: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

A Shure Educat iona l Pub l ica t ion

Wireless Microphone SystemsIntro

duct

ion

Page 2: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

[What’s Inside?]

[p.1]

IntroductionGet familiar with wirelessmicrophone systems.Eliminate cables connecting you to the sound system, gainingfreedom of mobility with noloss of sound.

[p.2]

Product GlossaryDiscover the componentsof a wireless system.

[p.4]

Concept GuideUnderstand the uniqueelectronics that makewireless systems work andthe features that helpdetermine the right wirelessoptions for you.

[p.6]

Needs AnalysisA series of questions toassess wirelessapplication possibilitiesand benefits for yourper formance situation.

[p.8]

Setup SnapshotsEasy-to-follow diagrams ofwireless system setups andhow they work for specificapplications.

[p.12]

Advanced ConceptsLearn more advancedwireless capabilities.

Wireless Microphone Systems

Page 3: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Conventional wired microphones conver t sound into an electrical audio signal that issent to the sound system through a cable. Live music stages that are crowded withcables from microphones for vocals, guitars, drums and other instruments canbecome a snake pit of overlapping wires.

Wireless microphones conver t audio signals created by microphones into radiosignals, which are sent by a transmitter through the air to a receiver. The receiverconver ts the radio signals back into audio signals which are then sent through thesound system. They eliminate the need for cables, so you’re no longer tethered to asound system or tripping through messy performing environments.

With continuous technological advances and improvements in sound quality andreliability, wireless microphones are more affordable and popular than ever. Theirpotential uses go far beyond the stage. You can find wireless microphones in exercisestudios, schools, houses of worship, presentation halls – anywhere a performer orpresenter wants true freedom of movement.

No cables. No worries.> Simplicity

Set up and go for it. Your stage is cleaner and your mics are less intrusive, so youcan concentrate on your performance.

> Mobility Be even more expressive. Wireless microphones cut you loose wherever you perform.

> Versatility Multiple microphone choices, system configurations and features mean wirelesssystems can adapt to nearly anything you do and any place you go.

Wireless Microphone Systems // 1

Wireless Microphone Systems

Introduction

Page 4: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

2 \\ Introduction Guide

Wireless Microphone Systems

Product Glossary

Bodypack TransmitterLavalier, Headworn and Instrument Microphones, as well asguitar cables, must plug into a Bodypack Transmitter to sendtheir audio signals. Sleek, lightweight bodypacks can be easilyclipped to clothing or a guitar strap.

HandheldMicrophoneTransmitterThis microphone/transmitterintegrates the transmitterinto the microphone handle,so both functions arecontained in one unit.

Like conventional wiredmicrophones, wirelesshandheld vocal microphonesare tailored to meet diverseperformance vocalrequirements and musicianpreferences. Many differentchoices are available.

Headworn Vocal MicRugged, comfor table, easy-to-position headsets providesuperior voice pickup in anyactive user setting.

Lavalier Vocal MicA range of sizes combinelow visibility with high-quality professionalaudio. They provide full,clear sound for speechapplications.

Clip-On Instrument MicA versatile solution for high volume wind, brass and percussion players.Gooseneck and clamp ensuresecure fit and positioning.

Guitar/Bass CableConnects any guitar to aBodypack for wirelessperformance.

[1] TransmittingTwo types of transmitters-handheld or bodypack – conver t audio signals to radio signalsso they can be sent, without a cable, to a wireless receiver at the mixing console.

Wireless Microphone Systems range from simple to sophisticated. But they all include variouscombinations of these key components:

• Transmitters – conver t the audio signal from the microphone to a radio signal. There are two types:Handheld Microphone Transmitter – combines handheld microphone element and transmitter in one unit.Bodypack Transmitter – wearable unit with a connector that accepts microphones or guitar cables.

• Microphones (for Bodypack Transmitters) – Headworn, lavalier and instrument microphones ideal for avariety of vocal and instrument applications

• Receivers – modules that receive radio signals sent from transmitters and convert them back to audio.

Page 5: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Diversity ReceiversThese have two antennas along with a smar tcircuit that selects or combines them for thebest signal quality. Since one antenna willalmost cer tainly be receiving a clear signal,the risk of dropout is greatly reduced.

Wireless Microphone Systems // 3

Single-Antenna ReceiversThese receivers use one antenna. They are the most cost-effective choice, but momentary dropouts can occur as theuser moves around. This happens whenpar t of the radio signal is reflected by metalobjects. This can cause loss of the signal atthe receiver’s antenna.

[2] ReceivingWireless receivers process signals sent from a Handheld Microphone Transmitter or aBodypack Transmitter. They come in these two basic antenna configurations:

Page 6: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

4 \\ Introduction Guide

Wireless Microphone Systems

Concept GuideThese technical and operating concepts help define how a wireless microphone systemfunctions and which is best suited to a specific application.

Frequency RangesEvery wireless microphone system transmits and receives sound on a specific radio frequency,known as the operating frequency. These frequencies can typically be grouped into two largebands, or ranges: VHF (very high frequency) and UHF (ultra high frequency). They are part of theoverall frequency spectrum shared by all kinds of other wireless devices, such as TV and radiobroadcasts and cellular phones.

VHF vs. UHFEach of these bands has their own benefits and potential liabilities for individual users. They canalso vary greatly in price, depending on the system. However, the sound quality of a wirelessmicrophone is determined by the microphone element and the audio circuitry in a particularsystem, not by the transmission frequency.

VHF (Very High Frequency) – VHF wireless microphone systems offer affordable options forbeginning performers to pros. Most VHF wireless systems operate on the same frequencies usedto broadcast television channels 7 to 13. But some VHF systems use non-TV frequencies (below174 MHz), which are also used for business radio and drive-through restaurant headsets.

UHF (Ultra High Frequency) – There are up to eight times more frequencies available for wirelessuse in the UHF range than in VHF, as well as additional dynamic range in audio signals. UHFsystems also have shorter, less visible antennas.

Frequency Selection Fixed Frequency – Fixed-frequency systems are pre-set to their operating frequency and cannot bechanged by the user. They are a more affordable choice particularly suitable for use in oneparticular area or installation.

Frequency Agile – Frequency-agile (tunable) systems allow users to quickly change frequencies toavoid interference from local TV channels, other wireless users or other external sources.

Using Multiple Wireless MicrophonesEach microphone needs its own frequency to operate and transmit properly. So it is not possible touse two wireless systems on the same frequency in the same venue or to use two wirelessmicrophones with just one receiver.

The individual frequency used by each microphone requires a certain amount of space within aparticular frequency band. When two wireless systems are used together, the frequencies must beseparated by some minimum amount that depends on the design of the system. If frequenciesare set too close, microphones will compete with each other, and each system will experiencenoisy interference and/or sound dropouts.

As more transmitters and receivers are added to a particular setup, interaction between frequenciesincreases. This interaction produces more interfering frequencies that need to be avoided. Moreadvanced wireless systems offer greater frequency selection, flexibility and the ability to combinemore receivers and transmitters to serve more users. Many of these systems offer pre-configuredgroups of compatible frequencies to accommodate multiple users, as well as software that canscan for the most clear frequencies in any one par ticular location.

Page 7: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Microphone BasicsThere’s more to a microphone than its shape. While invisible from the outside of amicrophone, these two fundamental operating principles can help fine tune the selection ofthe right microphone for your wireless system application.

Transducers Transducers are the elements inside a microphone head unit. There are two types: dynamicand condenser. Both conver t soundwaves produced by your voice or instrument intoelectrical signals that become amplified sound. But they differ slightly:

DynamicThese are workhorse microphone elements with great sound that stand up torugged regular use. They are also generally more affordable options.

CondenserThese produce a crisper, more defined sound and are better at capturingsubtle details of delicate voices and instruments. They also require power tooperate, which is supplied by the battery in a handheld wireless transmitter.

Polar PatternA polar pattern is the graphic representation of a microphone’s directional sensitivity, whichis how a microphone picks up sound from different directions. These are the three mostcommon polar patterns:

CardioidThese patterns pick up the most sound from in front of the microphone andsome from the sides They are less susceptible to feedback in loudenvironments.

SupercardioidThese are tighter patterns that help screen unwanted sound sources. They areperfect for individual instruments in a multi-instrument setting or singlesources in noisy environments. They also provide the best rejection offeedback when used with floor wedge monitor speakers.

OmnidirectionalOmnidirectional polar patterns are equally sensitive to sound from alldirections. These are most often found in lavalier microphones.

Wireless Microphone Systems // 5

Page 8: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Wireless Microphone Systems

Needs Analysis

What type of microphone /transmitter configuration bestfits your performance needs?

Would your performance benefitfrom a particular microphonedesign profile?

Your usage application is only one key factorin choosing a wireless microphone. Alsoconsider the microphone transducer designand polar pattern. These greatly impact howany wireless microphone reproduces yourlive sound.

For example, if you are a vocalist whoperforms onstage with loud monitors, youmight want a handheld transmitter with atight supercardioid polar pattern to minimizefeedback.

If you tend to sing softly, a condensermicrophone will more smoothly capture thesubtleties and details of your voice.

1 2

6 \\ Introduction Guide

[Microphone Configurations]Wireless system microphone and transmitter choices afford presenters and performers greatflexibility in matching an application to a wireless configuration.

ApplicationVocalist

Singing DancerSinging KeyboardistSinging Drummer Fitness InstructorDance Instructor

PresenterWorship LeaderStage Actors

Horn|Percussion

Guitar|Bass

ConfigurationHandheldMicrophone /Transmitter

Headworn Mic +Bodypack Transmitter

Lavalier Mic+Bodypack TransmitterOrHeadworn Mic +Bodypack Transmitter

Clip-On Mic +Bodypack Transmitter

Instrument Cable+Bodypack Transmitter

Page 9: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Where do you intend to use yourwireless system? One location? Many locations?

One LocationIf you intend to use the wireless system in one location, you simply need to make sure that you select a system thatoperates on frequencies compatible with your location’s VHF or UHF broadcast TV channel frequencies.

Multiple LocationsIf you intend to use the wireless system indifferent cities, you will probably encounterdifferent active TV channels. A frequency-agilewireless system lets you change frequenciesto adapt to changing situations as you travel.

International LocationsThere is no single wireless frequency usableworldwide. Regulations and frequencyallocation vary from country to country.

Tip: Visit www.shure.com/frequency to find outmore about which frequency range is best foryour requirements.

How many wireless systems will be in use at the time and location?

One SystemIf you are operating a single wireless systemin a location where there are no otherwireless systems in use, you will not haveany special multisystem needs to manage.

Multiple SystemsIf you operate more than one wireless systemand move from venue to venue, it is usuallymore convenient to mount receivers in asmall rack case. Some wireless systemsallow two receivers to mount together in onerack space. These can be used with anantenna splitter that feeds one “master” pairof antennas to serve all receivers.

There is a limit to the number of wirelesssystems that can be used in one location.Each system must transmit on its ownfrequency. And those frequencies must beselected carefully to prevent interference.

Better wireless systems allow for more units to be operated at the same timewithout interference. Some even includesystems that help find an open frequencyautomatically and avoid sources ofinterference.

Tip: UHF and VHF systems can usually becombined without problems.

3 4

Wireless Microphone Systems // 7

[System Configurations]The transmitter and receiver electronics in every wireless system are also designedto respond to the special needs of different user applications.

Page 10: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Singer

Single-Antenna Receiver

HandheldTransmitter

Your input to thehouse board

Signaltransmittedto Receiver

Signal sent tohouse sound ormonitors

Application Profile | HandheldA handheld wirelesssetup is great forper formers who wanta handheld vocalmicrophone that’s notconnected to abodypack transmitter. Ideal for:

VocalistsSpeakers / PresentersEmcees

Considerations: RF signalsSignal path from transmitter to receiverThe signal path and signal strength between transmitter and receiver is affected not only bydistance, but also by obstructions. Each installation location presents its own challenges.

Transmitter signals radiate in all directions, not just in a direct path. With single antennareceivers, direct and reflected signals can often cancel each other out, causing a sounddropout. Typically, single antenna receivers provide good performance outdoors or in areaswhere reflections are minimal. Diversity receivers, however, will provide superior performancein any environment.

These wireless system setup examples follow the wireless signal pathfor common vocal system configurations.

8 \\ Introduction Guide

Wireless Microphone Systems

Setup Snapshots

Page 11: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

ApplicationProfile | LavalierA lavalier microphoneand bodypack transmittersetup can work for anypresenter or performer.Ideal for:

Speakers / PresentersWorship LeadersTheater Stage Actors

ApplicationProfile | HeadwornFor situations whereperformers or presenterswork with louder soundsystems or use stagemonitor speakers, aheadworn microphone isa more effective choice.Ideal for:

Fitness / DanceInstructorsSinging Dancers or

Instrumentalists (such as drummers andkeyboardists)

Receiver and antenna placementPlace the receiver properlyReceivers are subject to interference from external sources that use radio frequencies.Where possible, keep receivers a few feet (or rack spaces) away from CD/DAT/MD playersand special-effects units.

Position antennas properlyIdeally, antennas should be positioned above an audience or other obstructions so that thetransmitter and receiver can “see” one another. When receivers are mounted in a rack,antennas must be located on the front panel or allowed to project through the top of therack. Antennas should be oriented ver tically or angled apar t to maximize the distancebetween antenna tips.

Wireless Microphone Systems // 9

Diversity Receiver

Lavalier

BodypackTransmitterYour input to the

house board

Signaltransmittedto Receiver

Signal sent tohouse sound ormonitors

Presenter

Page 12: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Guitarist

ApplicationProfile | GuitarA wireless guitar setuphelps guitarists movefreely anywhereonstage. Ideal for:

Electric GuitaristsAcoustic GuitaristsBass Guitarists

Considerations: PowerBatteriesUnlike most wired microphones, all wireless mic transmitters require batteries. Wirelessperformance suffers as batteries lose power. As a result, batteries are an impor tant andconstant replacement par t. Alkaline batteries offer the longest life for wireless applications.Rechargeable nickel-cadmium batteries, though an economical choice, typically last lessthan three hours before recharging is necessary. This shor t lifespan makes themundesirable for most performers.

10 \\ Introduction Guide

Wireless Microphone Systems

Setup Snapshots

Single-Antenna Receiver

BodypackTransmitter

Guitar Cable linksto Bodypack

Your input to thehouse mixer

Signaltransmittedto Receiver

Signal sent tohouse sound ormonitors

These wireless system setup examples follow the wireless signal path forcommon instrument system configurations.

Page 13: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

ApplicationProfile | Clip-OnA small, clip-oninstrumentmicrophone andBodypack Transmitteris a great wirelesssolution for manyacoustic instruments.Ideal for:

BrassWoodwindPercussion

Wireless Microphone Systems // 11

Saxophone

BodypackTransmitter

Clip-OnInstrument

Mic

Signaltransmittedto Receiver

Diversity Receiver

Your input to thehouse mixer

Signal sent tohouse sound ormonitors

Page 14: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Wireless Microphone Systems

Advanced ConceptsMore technical aspects of wireless microphones:

Traveling with a wireless systemSelecting frequencies that avoid local TV channels in your home location is relatively easy.However, that can change if you are a touring performer who also goes to other cities or countries.

There is a portion of the VHF spectrum not used for television broadcasts that is availableanywhere in the U.S. For this reason, these frequencies are called “traveling frequencies.” However, these frequencies are also shared by other types of users. In addition, only three traveling frequencies can be used together in one location without interference, which limits multi-user configurations.

Frequency-agile systems allow the user to change frequencies to avoid active TV channels or otherinterference sources encountered when traveling. Traveling overseas makes frequency selectioneven more difficult. A wireless system purchased in one country may be illegal or unusable inanother country. There is no single wireless frequency that is legal worldwide, so it is usually betterto rent a system from a reputable supplier in each country.

TV channel interferenceBoth VHF and UHF wireless microphones operate on frequencies that are primarily used tobroadcast television signals. The introduction of digital television is increasing the number ofoccupied channels. It is sometimes possible for a wireless microphone to operate on an activetelevision channel (for example, deep inside a large building with poor TV signal penetration).However, for reliable operation, it is important to choose wireless frequencies that are not used forTV broadcasts within a 50-mile radius of the user’s location.

Factors that make TV interference worse include:• Being outdoors• Using wireless mics in a location close to the TV transmitter antenna• Using a wireless microphone transmitter more than 50 feet from the receiver• Poor placement of receiver antennas

12 \\ Introduction Guide

Page 15: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

Wireless Microphone Systems // 13

Notes

Page 16: Introduction to Wireless Microphone Systems · 2 \\ Introduction Guide Wireless Microphone Systems Product Glossary Bodypack Transmitter Lavalier, Headworn and Instrument Microphones,

AL1502A1/04 ©2004 Shure IncorporatedPrinted in the USA 10K

Learn more.Wireless Microphone Systems:Selection & Operation GuideThis booklet provides greater technical detail about specificwireless microphone systems, components, frequency selection,usage applications, setup suggestions and system expansion.Request your copy by contacting Shure at one of the numberslisted below.

You can also download a PDF of this guide and data sheets for any Shure wireless microphoneproduct at the Shure website:•www.shure.com/wireless•www.shure.com/datasheets

Additional Shure educational publications available:• Audio Systems Guide for Houses of Worship• Audio Systems Guide for Meeting Facilities• Audio Systems Guide for Video Production• Personal Monitor Systems | Selection & Operation Guide• Personal Monitor Systems | Introduction Guide • Mic Techniques for Music–Sound Reinforcement• Mic Techniques for Music–Recording

United States:Shure Incorporated5800 West Touhy Avenue, Niles, IL 60714-4608 U.S.A.Phone: 847-600-2000 Fax: 847-600-1212

Europe:Shure Europe GmbHPhone: 49-7131-72140 Fax: 49-7131-721414

Asia:Shure Asia LimitedPhone: 852-2893-4290 Fax: 852-2893-4055

Elsewhere:International AmericasMiddle East & AfricaPhone: 847-600-2000 Fax: 847-600-6336

www.shure.com