AKG Acoustics WMS 4000 manual Setting UP Multichannel Systems, IP 3 Intercept

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AKG WMS MULTICHANNEL TECHNOLOGY

SETTING UP MULTICHANNEL SYSTEMS

HOW TO DEAL WITH INTERMODULATION AND KEEP YOUR FREQUENCIES STRAIGHT

Whenever two or more signals are transmit- ted by a non-ideal system, undesired inter- modulation products will be created, cau- sing distortions (see also WMS 400, p. 31). An ideal system would deliver an output signal that is identical to the input signal over the whole frequency range even at lar- ger amplitudes, and no problems would arise.

In practice, however, ideal systems do not exist, as transistors in particular have only a relatively narrow linear gain range. This is why the transmission of several signals via nonlinear systems, such as transmitters and receivers, will result in unwanted arti-

facts generated by intermodulation. These intermodulation products have to be dealt with somehow in practice.

The order of intermodulation products depends on the nonlinearity of the system response curve; the amplitudes of intermo- dulation products will always grow in pro- portion to the product of the mathematical powers of the fundamental signals genera- ting a given intermodulation product. In reality, third-order intermodulation pro- ducts tend to be particularly troublesome because they rise much more rapidly than the fundamental signal, thus turning into real, i.e., audible noise.

Whenever the frequency of the desired sig- nal coincides with that of an intermodula- tion product the signal will be distorted. Moreover, the intermodulation product may activate the receiver's squelch function if the amplitude of the intermodulation fre- quencies exceeds the squelch threshold.

Obviously, the effective impact of intermo- dulation distortion also depends on the distance between transmitter and receiving antenna. In the case of wireless micropho- nes transmitting on an intermodulation fre- quency, the desired signal is often ruined by intermodulation distortion if you move the transmitter too far away from the receiver.

Ideal and real gain curves of ideal and real amplifiers

High audio input levels may overload the amplifier, so the peaks of the amplified signal are clipped as a result of saturation. The compression characteristic may be des- cribed by a polynomial (i.e., the sum of multiples of powers of a variable X). This polynomial includes all powers, with the odd powers (3, 5, 7, ...) responsible for intermodulation in multichannel systems. Because of its high coefficient, the third power term is especially important which is why third-order intermodulation products are dominant. The reciprocal value of the third-order coefficient defines the IP 3 Intercept (see below), which is the most important parameter for the intermodulation resistance of an RF amplifier. A smaller third-order coefficient of the trans- mission polynomial means a higher IP 3, which implies greater linearity of the RF amplifier and thus better resi- stance to intermodulation distortion.

IP 3 Intercept

The Intercept marks the intersection of the theoretical linear transfer curve for the wanted signal’s amplifier res- ponse curve and the theoretical linear transfer curve for the third-order intermodulation product. It is never actual- ly reached because the amplifier will compress the wanted signal before it reaches the IP 3 Intercept level.

The higher the Intercept of a radio transmission system, the lower the IM risk, and the more channels may be used within a given frequency band.

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Contents Wireless Page Wireless Technology for the Future Pioneer in Acoustics for Over 50 YearsHow it all started … Die DYN Series120 DYN Founders Dr. Rudolf Görike and Ing. Ernst Pless12 a 180Early products Company nameBreakthrough Expansion coursePeter Wolf Rock me AmadeusAKG expands its activities in the wireless market Turning pointWMS New research centerHOW Radio Signals are Transmitted Case for wireless micsJust like a radio set Radio waves instead of cablesSignal propagation Positioning the receiverRule no WavelengthBandwidth Frequency Modulation FMInterference Example of AKG WMS 40 carrier frequenciesModular Solutions to Meet Individual Requirements Clip-on or head-worn microphone For presentersHead-worn microphone for extreme Activities like aerobics and sportsHandheld Mics for Lead and Backing Vocals On/off switch VolumeMicrophone cleaning and maintenance Angle of incidencePT 40 Portable transmitter Mini XLR connector Rear panel and battery compartmentHEAD-WORN Mics for Lead and Backing Vocals Flexible antennaSR 40 diversity Receiver ON/OFF switch AntennasAF LEDs Alternative receivers Diversity LEDsBattery compartment XLR connectorSO 40 snapon transmitter Release button Color codeXLR connector pin 2 hot Setting the squelch thresholdBattery charging made easy TM 40 Transmitter module Status LEDWireless and supremely flexible On/Off switch AF LEDs3700M 3800M 880MMP 40 Micropen for Presenters Cable compartmentMicrophone Color code pen clipMP 40 micropen in handheld mode PR 40 Portable receiver ON/OFF switchDetachable microphone Put it in your pocket …More Goodies for Presenters PT 40 Bodypack transmitterWith C 444 L head-worn or C 417 L lavalier microphone With proven D 880M microphone elementAvoiding feedback 444 L417 L Wireless Systems for Maximum Mobility Training communicationsPR 40 Portable receiver PT 40 careAKG WMS 40 UHF for Instruments Radio Links for Portable InstrumentsConnecting to microphone or line inputs MicroMic C 411 L pickupInstrument MicroMics Instrument MicroMic Instrument MicroMicsJack plug AccessoriesGB 40 Guitarbug for Guitar and Bass FlexJack for all electric bass models Guitar system in a bagFlexJack for all electric guitar models HOW Multichannel Technology Works Use before each performance WMS frequency band with TV transmitterIntermodulation Automatic frequency setup Shadow loss Multipath transmissionProblem poor audio Troubleshooting HintsProblem no sound microphone does not function Modular Solutions for Custom Reqirements SR 400 Receiver On/Off switch Recessed level control Status LEDsBacklit LC display Metal caseAuto setup Rehearsal modeRange of accessories for complex applications Infrared transmissionOn-Mute/Program-Off switch Extremely rugged spring steel mesh grillInfrared sensor HT 400 Handheld transmitter DisplayRugged mini XLR connector Jack for external mute switchBattery status display Frequency preset LCD display Frequency in MHz Low battery capacity warningInput jack for a local or central power supply e.g., PSU User Friendly Quick ChargerLocking DC jack Integrated charging contacts for direct chargingPSU 4000 Central power supply unit AB 4000 Antenna boosterRA 4000 B Omnidirectional wideband booster antenna HPA 4000 Headphone amplifierSetting UP Multichannel Systems IP 3 InterceptFrequencies Microphone a carrier frequencySpectrum analyzer trace Frequency Management a good idea for any multichannel system Here is a proven way to add clean frequencies Far-near differenceStage a Stage B Band I + 0,15Modular Solutions for Professional Requirements SELECTING, Placing and Using Antennas Signal loss caused by the audienceSkin Fat Muscle CartilageSELECTING, PLACING, and Using Antennas Cable position a Cable position BCable type Impedance GageShort antenna cable runs Drawbacks Stadium exampleStadium theater, opera house example TV studio Theater Speech Vocals Guitar/Bass InstrumentsLive sound RA 4000 B CU 4000/BP HUB 4000 Network concentratorSRA 1 Passive wideband dirctional antenna Battery status readout Frequency presetsAutomatic gain setting Battery compartment Jog switchJack for remote Mute switch Silent Mode settingInscribable color code element Magnesium body Hidden pilot toneCUTTING-EDGE True Diversity Receiver Backlit display Half-rack 19 all-metal caseProgrammable status display SR 4000 ReceiverBattery life display Environment Scan and Rehearsal ModeEnvironment Scan Professional XLR and jack outputsIntelligent WAY to Power WMS 4000 Transmitters Charging status display LED Recovery key and LEDCU 4000 Charging unit Lockable DC jack Such as a PSUIntegrated temperature sensor CU 4000 Charging unit in a flight caseInternal RAM Data interface to transmitter electronicsDaisy-chaining outputs BNC antenna outputsBNC antenna inputs AKG WMS PS Selecting and placing antennas Antennas Tailored to Every SituationCabling example/cable lengths ASU 4000 Remote powerd adapter for antennas SRA 1 Passive wideband directional antennaSRA 2B Active wideband directional antenna ZAPD-21 Antenna combinerStandard PC accessories. This allows you to Link Between the WMS 4000 and a PC NetworkAs RF levels on site. This makes it incredibly Example WMS 4000/PC networkYou can even set up the basic parameters Get a Cup Setup Mode Moving PC Rehearsal ModeYour Computer AS a WMS 4000 Control Center Ensures maximum operating reliabilityAKG WMS 4000 Power Supply Recommended headphones Monitoring Without a MixerLine input jacks, DC input lockable Jog control StudioSpecification Amount Description SeminarsRA 4000 B PSUAmount Description Example 10-CHANNEL System for Tour SoundTour Sound AKG WMS Practical Examples Example 16-CHANNEL System for Mobile USE Vienna KonzerthausWMS 4000 Wiring WMS 4000 mobile rackGala Musical Couples, August Detailed system layout is shown on the following pagesWMS 4000 16-CHANNEL Setup AKG WMS Practical Examples Example 46-CHANNEL System for AN Opera House High-tech for pure enjoymentStage Channels Channels WMS 4000 1-CHANNEL Setup SpecificationAKG WMS Practical Examples Guitar Violin and violaBanjo See guitar. top rightSaxophone ClarinetTubas TromboneAV/sound company Bars and clubsSound systems Meeting and social roomsAKG Wireless Systems AT a Glance Microtools HT/PTMP 40 micropen ALL the Specs AT a GlanceSystem PR 40 diversity Mounting kit, 2 antennasDefinitions from a to Z Electromagnetic Wave Spectrum Distortion EnvironmentDirectional Antenna DiversityPhantom Power FeedbackFrequency Management Frequency ModulationHypercardioid Ultra-directional CardioidPop Noise Pressure Gradient MicrophoneSignal Loss Signal-to-noise S/N RatioReflection Remote AntennaIndex Selected KeywordsAppendix 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.