Harman 4800, 4820 user manual AFS On/Off switch, Clear Live and Clear All buttons, Mode switch

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Section 6

 

 

 

 

DriveRack

 

 

 

®

 

 

Detailed Parameters

 

 

6.11 - Advanced Feedback Suppression (AFS®) Insert

The DriveRack 4800/4820 offers the exclusive dbx Advanced Feedback Suppression (AFS) feedback elimination module as an Insert processing function on the Input channels. This feedback suppression algorithm reduces feedback by first finding the location of a feedback frequency and then placing a very sharp notch filter at the exact frequency that is feeding back. Because the AFS algorithm can find the exact frequency down to 1/100th of a Hertz, the notch filter used can be extremely sharp, in most cases 1/80th of an octave. These sharp notch filters are so narrow that in most cases they cannot be heard, so the sonic integrity of the system remains intact. With the AFS algorithm active, the unit removes only the feedback frequencies without affecting the remaining audio spectrum.

AFS On/Off switch

This turns the AFS function on or off.

Clear Live and Clear All buttons

These buttons (when selected) reset the feedback filters. If Clear Live is selected, only the live filters are reset. If Clear All is selected, then all of the filters are reset.

Mode switch

The Mode switch toggles between Fixed and Live mode. Fixed mode sets Fixed filters and Live mode sets Live filters. Fixed filters will remain in place until they are reset. Live filters will either remain until they are needed for another feedback frequency, or they will “Lift” (if Live filter Lift is engaged). Fixed mode is used for setting up the algorithm; in fixed mode the algorithm is more sensitive to system resonances and Fixed (or locked) filters are set. The best way to set Fixed filters is to open all the system microphones and without any signal source present slowly raise the system gain. As resonances are reinforced the algorithm will lock onto those frequencies and set Fixed filters. Once all the Fixed filters are set, the unit can be placed into Live mode. In Live mode the filters are also set when a resonance is recognized. However, in Live mode this filter can be moved to another frequency if it is needed in that location. Live filters also have the capability of “Lifting”, which means that each Live filter can have a timer associated with that filter. Once the timer elapses, the algorithm will check to see if the filter is still needed. If it is needed, the filter remains. If it is no longer needed, the filter is removed and is then ready to be placed elsewhere.

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DriveRack® 4800/4820 User Manual

 

 

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Contents 4800/4820 Importantsafetyinstructions Important Safety Instructions Table of Contents DriveRackDriveRack DriveRack Features DriveRack 4800/4820 Features IntroductionDriveRackDriveRackIntroduction Service Contact Info WarrantyIntroductionDriveRack Front panel Getting Started Rear Panel 4800/4820 Getting Started Front PanelInput Channel Select A-D Ouput Channel SelectThreshold Meters RTA Input JackGettingStarted System Architect Features System Architect Control SoftwareMute Buttons Installation Minimum System Requirements for System Architect areRecommended System Requirements DriveRack Attributes DriveRack Philosophy DriveRack 4800/4820 Philosophy AttributesNavigation Front Panel Operation NavigationModes of Operation Return to Edit mode by pressing the Preset button DriveRack While in Edit mode press and hold the UTILITY/METER button DriveRack DriveRack Module view Software Operation DriveRack Philosophy SystemArchitectDriveRack4800/4820FileStorageSystem Architect DriveRack 4800/4820 Philosophy Module ViewSoftware Operation Device WindowDevice View Features Device File MenuDevice Edit Menu Device Tools MenuPreset Tool Device View MenuDevice Help Menu Meters Mutes and SolosVenue View Venue File MenuSoftwareGUI SoftwareOp rationOverview Venue View MenuVenue Insert Menu Venue Panel Menu Venue Tools MenuVenue Window Menu Venue Help MenuDriveRack Front panel Press and hold the RTA/LOAD button to load the preset UseDriveRack Store the name by pressing the STORE/DELETE button DriveRack GUI Operation DriveRack DriveRack Detailed Detailed Parameters Input MixerSelected Source Switch Detailed Parameters Input RouterEQ On/Off switch Flat/Restore switchFrequency switch Detailed Parameters Input Graphic EQDetailed Parameters Input 9-Band Parametric EQ Detailed Parameters Input Delay Delay On/Off switchDelay fader Units switchMaster Mute switch Detailed Parameters Output MixerChannels A-D Detailed Parameters Output Router Detailed Parameters OutputBandpassFilter/Crossover Detailed Parameters Output 6-Band Parametric EQ Detailed Parameters Output Delay AFS On/Off switch Mode switchClear Live and Clear All buttons Type switch Live Filter Lift switchDetector Highpass fader Sensitivity faderAGC On/Off switch Detailed Parameters Automatic Gain Control AGC InsertThreshold fader Target faderLimiter Auto On/Off switch Window faderAttack fader Release faderAutoWarmth On/Off switch Detailed Parameters AutoWarmth InsertAmount fader Compressor On/Off switch Detailed Parameters Compressor InsertOverEasy fader Ratio faderAuto On/Off switch Hold faderDe-Esser On/Off switch Detailed Parameters De-EsserInsertFrequency fader Width faderGate On/Off switch Detailed Parameters Noise GateMax Attenuation fader Limiter On/Off switch PeakStopPlus On/Off switchDetailed Parameters Limiter Insert PeakStopPlus Overshoot faderDetailed Parameters Notch On/Off switch Detailed Parameters Notch Filter InsertSubHarmonic Synth On/Off switch Detailed Parameters SubHarmonic Synthesizer InsertSubHarmonic Level fader 24-36Hz Level faderUtilities Utilities MiscellaneousGains & Trims Sample RateAccess Rights Preset RangeUtilities Real Time Clock UsersDriveRack DriveRackAppendix Specifications AppendixDriveRackDriveRackAppendix Block Diagram Preset Table Crossover TableDigital I/O and Clocking Word Clock Termination ZoneControllerWiringandInstallation Zone Controller WiringZone Controller Installation AppendixDriveRack GND ZC-4 Wiring Diagram Factory Reset Factory Reset InformationPower-Up Button Functions Hard Factory ResetEthernet Networking Overview of TCP/IP BasicsIP address SubnetConnecting the Computer Directly to the DriveRack Dhcp Dynamic Host Configuration ProtocolAssumptions Setup of a Simple Isolated Ethernet Network Using Dhcp ProxyVirtual Private Networks VPN Network Considerations and LimitationsNetworkTroubleshooting Software FirewallEthernet Link Copyrights AppendixDriveRack DriveRackAppendix 18-0353-B