AKG Acoustics WMS 4000 manual Microphone a carrier frequency, Spectrum analyzer trace, Frequencies

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AKG WMS MULTICHANNEL TECHNOLOGY

Microphone A carrier frequency

Intermodulation of carrier frequencies A and B

Microphone B carrier frequency

Spectrum analyzer trace

The trace clearly shows that third-order intermodulation

Spectrum analyzer trace

 

products are only 38 dB lower in level than the carrier

 

 

frequencies.

 

Intermodulation trace on a spectrum analyzer display Third-order intermodulation products from three carrier frequencies.

The received signal level declines in pro- portion to the square of the distance bet- ween transmitter and receiver, and the intermodulation level produced in the receiver declines in proportion to the third power of the received signal level. This implies that intermodulation declines expo- nentially, in proportion to the sixth power of the distance between transmitter and recei- ver. If the distance is longer than 66 feet (20 m), receiver intermodulation is drow- ned out by noise. What remains is another important type of intermodulation distor- tion that has not yet been mentioned: trans- mitter intermodulation. In this case, the intermodulation products are not generated in the receiver, but in the transmitters, and are radiated by them along with the desired

carrier frequencies. This will only happen, however, if there is enough crosstalk of car- rier frequencies between two neighboring transmitters that intermodulate with each other. In this case, the antenna of one transmitter receives the carrier signal of a neighboring transmitter. If this signal makes it into the non-linear output stage of the transmitter, the first harmonic of the desired signal will transform it into a signal whose frequency is indistinguishable from the receiver intermodulation. The same happens in the other transmitter that will generate a mirror-image intermodulation product. Curiously, a love duet close to the receiving antennas may lead to intermodu- lation distortion caused by the nonlinear receiver. If the two singers move away, the

intermodulation remains unchanged, but is now produced in the transmitters. In large multichannel systems, reducing the RF output of the transmitters is a way to bring down transmitter intermodulation by mini- mizing the nonlinear response of the trans- mitter's output stage. The RF output of WMS 4000 transmitters, for example, can be reduced from 50 mW to 10 mW (ERP –Equivalent Radiated Power).

Here are some hints on how to minimize receiver intermodulation:

Always lay out the antenna system so as to ensure reliable transmission from every point on the stage. Moreover, be sure to use only the types of cables recommended in the user’s manual. The distance between

Intermodulation trace on a spectrum analyzer display Intermodulation products from 2 carrier frequencies, 3rd-order IMD and 5th-order IMD.

transmitters and active antennas should be at least 15 feet (5 m) (see also Antenna Position Check Applet on p. 45). Increasing the input attenuation of the antenna system helps, as does reducing the transmitter RF output to 10 mW. The latter has proved particularly useful for hand-held transmitters in situations where range is not an important consideration; generally, the RF output level used should always be just high enough to ensure adequate trans- mission. Systems with a higher transmitter RF output (ERP) are more prone to inter- modulation problems, but this is compen- sated for by their better resistance to elec- trosmog.

When multichannel systems are used on Broadway, for instance, only the strongest will survive.

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Contents Wireless Page Pioneer in Acoustics for Over 50 Years Wireless Technology for the FutureDie DYN Series How it all started …120 DYN Founders Dr. Rudolf Görike and Ing. Ernst Pless180 12 aEarly products Company nameExpansion course BreakthroughPeter Wolf Rock me AmadeusTurning point AKG expands its activities in the wireless marketWMS New research centerCase for wireless mics HOW Radio Signals are TransmittedJust like a radio set Radio waves instead of cablesPositioning the receiver Signal propagationWavelength Rule noFrequency Modulation FM BandwidthInterference Example of AKG WMS 40 carrier frequenciesModular Solutions to Meet Individual Requirements For presenters Clip-on or head-worn microphoneHead-worn microphone for extreme Activities like aerobics and sportsHandheld Mics for Lead and Backing Vocals Volume On/off switchMicrophone cleaning and maintenance Angle of incidenceRear panel and battery compartment PT 40 Portable transmitter Mini XLR connectorHEAD-WORN Mics for Lead and Backing Vocals Flexible antennaAntennas SR 40 diversity Receiver ON/OFF switchAF LEDs Alternative receivers Diversity LEDsXLR connector Battery compartmentSO 40 snapon transmitter Release button Color codeSetting the squelch threshold XLR connector pin 2 hotTM 40 Transmitter module Status LED Battery charging made easyOn/Off switch AF LEDs Wireless and supremely flexible3700M 3800M 880MCable compartment MP 40 Micropen for PresentersMicrophone Color code pen clipPR 40 Portable receiver ON/OFF switch MP 40 micropen in handheld modeDetachable microphone Put it in your pocket …PT 40 Bodypack transmitter More Goodies for PresentersWith C 444 L head-worn or C 417 L lavalier microphone With proven D 880M microphone element444 L 417 LAvoiding feedback Training communications Wireless Systems for Maximum MobilityPT 40 care PR 40 Portable receiverRadio Links for Portable Instruments AKG WMS 40 UHF for InstrumentsMicroMic C 411 L pickup Connecting to microphone or line inputsInstrument MicroMics Instrument MicroMic Instrument MicroMicsAccessories GB 40 Guitarbug for Guitar and BassJack plug Guitar system in a bag FlexJack for all electric guitar modelsFlexJack for all electric bass models HOW Multichannel Technology Works WMS frequency band with TV transmitter IntermodulationUse before each performance Automatic frequency setup Multipath transmission Shadow lossTroubleshooting Hints Problem no sound microphone does not functionProblem poor audio Modular Solutions for Custom Reqirements Status LEDs SR 400 Receiver On/Off switch Recessed level controlBacklit LC display Metal caseRehearsal mode Auto setupRange of accessories for complex applications Infrared transmissionExtremely rugged spring steel mesh grill On-Mute/Program-Off switchInfrared sensor HT 400 Handheld transmitter DisplayJack for external mute switch Rugged mini XLR connectorBattery status display Frequency preset LCD display Frequency in MHz Low battery capacity warningUser Friendly Quick Charger Input jack for a local or central power supply e.g., PSULocking DC jack Integrated charging contacts for direct chargingAB 4000 Antenna booster PSU 4000 Central power supply unitRA 4000 B Omnidirectional wideband booster antenna HPA 4000 Headphone amplifierIP 3 Intercept Setting UP Multichannel SystemsMicrophone a carrier frequency Spectrum analyzer traceFrequencies Frequency Management a good idea for any multichannel system Far-near difference Here is a proven way to add clean frequenciesStage a Stage B Band I + 0,15Modular Solutions for Professional Requirements Signal loss caused by the audience SELECTING, Placing and Using AntennasSkin Fat Muscle CartilageCable position a Cable position B SELECTING, PLACING, and Using AntennasCable type Impedance GageStadium example Stadium theater, opera house exampleShort antenna cable runs Drawbacks Speech Vocals Guitar/Bass Instruments Live soundTV studio Theater CU 4000/BP HUB 4000 Network concentrator SRA 1 Passive wideband dirctional antennaRA 4000 B Frequency presets Battery status readoutAutomatic gain setting Battery compartment Jog switchSilent Mode setting Jack for remote Mute switchInscribable color code element Magnesium body Hidden pilot toneBacklit display Half-rack 19 all-metal case CUTTING-EDGE True Diversity ReceiverProgrammable status display SR 4000 ReceiverEnvironment Scan and Rehearsal Mode Battery life displayEnvironment Scan Professional XLR and jack outputsCharging status display LED Recovery key and LED Intelligent WAY to Power WMS 4000 TransmittersCU 4000 Charging unit Lockable DC jack Such as a PSUCU 4000 Charging unit in a flight case Integrated temperature sensorInternal RAM Data interface to transmitter electronicsBNC antenna outputs BNC antenna inputsDaisy-chaining outputs AKG WMS PS Antennas Tailored to Every Situation Cabling example/cable lengthsSelecting and placing antennas SRA 1 Passive wideband directional antenna ASU 4000 Remote powerd adapter for antennasSRA 2B Active wideband directional antenna ZAPD-21 Antenna combinerLink Between the WMS 4000 and a PC Network Standard PC accessories. This allows you toAs RF levels on site. This makes it incredibly Example WMS 4000/PC networkGet a Cup Setup Mode Moving PC Rehearsal Mode You can even set up the basic parametersYour Computer AS a WMS 4000 Control Center Ensures maximum operating reliabilityAKG WMS 4000 Power Supply Monitoring Without a Mixer Recommended headphonesLine input jacks, DC input lockable Jog control StudioSeminars Specification Amount DescriptionPSU RA 4000 BExample 10-CHANNEL System for Tour Sound Tour SoundAmount Description AKG WMS Practical Examples Vienna Konzerthaus Example 16-CHANNEL System for Mobile USEWMS 4000 mobile rack WMS 4000 WiringGala Musical Couples, August Detailed system layout is shown on the following pagesWMS 4000 16-CHANNEL Setup AKG WMS Practical Examples High-tech for pure enjoyment Example 46-CHANNEL System for AN Opera HouseStage Channels Channels Specification WMS 4000 1-CHANNEL SetupAKG WMS Practical Examples Violin and viola GuitarBanjo See guitar. top rightClarinet SaxophoneTubas TromboneBars and clubs AV/sound companySound systems Meeting and social roomsMicrotools HT/PT AKG Wireless Systems AT a GlanceALL the Specs AT a Glance SystemMP 40 micropen Mounting kit, 2 antennas PR 40 diversityDefinitions from a to Z Distortion Environment Electromagnetic Wave SpectrumDirectional Antenna DiversityFeedback Phantom PowerFrequency Management Frequency ModulationCardioid Hypercardioid Ultra-directionalPop Noise Pressure Gradient MicrophoneSignal-to-noise S/N Ratio Signal LossReflection Remote AntennaSelected Keywords IndexAppendix Appendix Appendix Appendix Appendix Page AKG ACOUSTICS, U.S
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WMS 40, WMS 400, WMS 4000 specifications

AKG Acoustics has long been recognized as a premier brand in the professional audio industry, particularly in the realm of wireless microphone systems. Among its celebrated offerings, the WMS 4000, WMS 400, and WMS 40 series stand out for their advanced technology and robust performance, catering to a range of applications from live performances to studio recordings.

Starting with the WMS 4000, this system is engineered for versatility and reliability. It features a sophisticated transmission diversity system that minimizes dropouts and ensures clear audio quality. The WMS 4000 offers an extensive frequency range, accommodating diverse environments and frequencies. A standout feature is its digital pilot tone, which automatically mutes the transmitter when it is switched off, effectively preventing unwanted noise during transitions. With a range of up to 300 meters, the WMS 4000 is ideal for large venues, allowing performers ample space to move without compromising sound quality.

Next, the WMS 400 series maintains the high standards set by its predecessor while providing a more accessible option for mid-level performers. It combines ease of use with quality audio performance, boasting a user-friendly interface that simplifies setup and operation. The WMS 400 employs an efficient frequency management system, which automatically scans the environment to select the best frequencies available, ensuring optimal performance with minimal interference. The system also features a rugged metal chassis, enhancing durability for live applications.

The WMS 40 series serves as an entry-level solution, perfect for beginners and small venues. It is lightweight and features a straightforward design, making it easy to operate for users without extensive technical knowledge. One of its most notable characteristics is its plug-and-play functionality, allowing for quick setup without complicated configurations. The WMS 40 series also offers excellent sound quality through its crystal-clear audio transmission and robust reception, making it a popular choice for schools, theaters, and small events.

All of these systems benefit from AKG's heritage in sound engineering, incorporating advanced audio processing technologies that ensure superior sound fidelity. They also come with a variety of microphone options, including handheld, lavalier, and headworn microphones, providing flexibility to meet different performance needs. Whether for a professional stage or an intimate setting, the AKG WMS series delivers outstanding performance, reliability, and user-friendly features that cater to a wide range of audio applications.