® ™ AFS 224 Dual Channel Advanced Feedback Suppression Processor User Manual
IMPORTANT SAFETY INSTRUCTIONS WARNING FOR YOUR PROTECTION READ THESE INSTRUCTIONS: CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN A T T E N T I O N : RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR W A R N I N G : TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE The symbols shown above are internationally accepted symbols that warn of potential hazards with electrical products.
IMPORTANT SAFETY INSTRUCTIONS U.K. MAINS PLUG WARNING ELECTROMAGNETIC COMPATIBILITY This unit conforms to the Product Specifications noted on the Declaration of Conformity. Operation is subject to the following two conditions: • this device may not cause harmful interference, and • this device must accept any interference received, including interference that may cause undesired operation. Operation of this unit within significant electromagnetic fields should be avoided.
AFS 224 Table of Contents Table of Contents Defining the AFS 224 ..............................................i Service Contact Info ...............................................ii Warranty ..................................................................ii Installation Recommendations...............................1 Basic Connections ..................................................1 Rear Panel Connections .........................................2 Front Panel Connections............................
AFS 224 AFS 224 Operation ®
Introduction INTRODUCTION AFS 224 Congratulations on your purchase of the dbx Professional Products AFS 224. The AFS 224 Advanced Feedback Suppression processor was designed to provide state-of-the-art feedback elimination processing, while maintaining a simple and intuitive control interface. From the powerful DSP module to the no-nonsense user interface, the AFS 224 provides all the processing and control necessary for both installation and live use.
AFS 224 Competitor’s Feedback Elimination Introduction dbx AFS™ 1/3 Octave EQ For more information regarding dbx Advanced Feedback Suppression (AFS™) technology, please refer to the white paper section online at: www.dbxpro.com. Service Contact Info If you require technical support, contact dbx Customer Service. Be prepared to accurately describe the problem. Know the serial number of your unit - this is printed on a sticker attached to the rear or side of the unit.
Operation Installation / Connections AFS 224 a period of two years. A Return Authorization number must be obtained from dbx by telephone. The company shall not be liable for any consequential damage as a result of the product's use in any circuit or assembly. 4. dbx reserves the right to make changes in design or make additions to or improvements upon this product without incurring any obligation to install the same additions or improvements on products previously manufactured. 5.
AFS 224 Operation Rear and Front Panels Rear Panel AFS 224 Rear Power Cord Receptacle: Connects AC power to the AFS 224. Input Connectors: Two types of input connectors are provided for input connections: female locking XLR type connectors, and 1/4” tip-ring-sleeve phone jack connectors. The maximum input level that the processor can accept is +20dBu (ref: 0.775Vrms). Operating Level Switch: This button allows you to select between either +4dBu or -10dBV nominal operating level.
Operation AFS 224 User Setup AFS 224 Filter Q's +3 +3 +2 +2 Music High - 1/80th Octave +1 +1 -0 -0 -1 -1 Music Med - 1/20th Octave -2 d B -3 u -4 Music Low - 1/10th Octave -5 Speech - 1/5th Octave -2 d -3 B u -4 -5 -6 -6 -7 -7 -8 -8 -9 700 750 820 850 900 .95k 1k 1.2k -9 Hz Live Filter Lift: Live Filter Lift provides maximum sonic integrity by removing unnecessary feedback filters.
AFS 224 User Setup Operation If no insert points are available, then method 4 would be utilized. In this situation, be sure that the AFS 224 input level allows the 0 and +10 dBu LEDS to light as indicated above. The input level to the amplifiers may have to be reduced in this situation so that they are not overdriven by the signal from the AFS 224. B – Setup Mode The AFS 224 setup mode is used to set the Total Number of Filters and the Number of Fixed Filters in each channel.
Operation AFS 224 User Setup C-1 Ringing out a system Fixed mode filters are set before a performance in a process called "ringing out a system". This is done after all other system EQ'ing has been done. First, bring down the main mix, turn off all music sources and open all the mics. Place the AFS 224 into fixed mode by pressing the button for the channel. A button lighting green indicates Fixed mode for that channel.
AFS 224 User Setup Operation D-1 Using Live Filter Lift Live Filter Lift provides maximum sonic integrity by removing unnecessary feedback filters. The Live Filter Lift function provides a timer for each of the Live Filters. This timer length can be adjusted by pressing the button, and can be switched between off, 1 minute, 10 minutes or 60 minutes. The filter lift default time is 10 minutes from the factory.
Operation AFS 224 Application Guide Applications Application 1 - Insert On the Microphone Channel This application is ideal for dedicated feedback suppression on microphone channels of a mixing console. This application provides the user with individual channels of 24 filter of feedback suppression per microphone. 1. Connect the channel insert output from the mixer to the input of the AFS 224. 2. Connect the output of the AFS 224 to the insert return of the mixer.
AFS 224 Operation Application Guide Application 2 - Insert On the Main Stereo Outputs of a Mixing Console This application is ideal for dedicated feedback suppression on the outputs of a mixing console. This application provides the user with dual channels of 24 filters of feedback suppression per channel. 1. Connect the stereo output inserts of the mixer to the inputs of the AFS 224. 2. Connect the outputs of the AFS 224 to the insert returns of the console. 3. Apply power to the mixer and amplifiers.
Operation AFS 224 Applications Guide Application 3 - Insert on the Subgroups of a Mixer This setup is ideal for applications that require feedback suppression on certain instruments such as microphones, while keeping instrument that desire feedback (such as guitars) separated. This application provides the user with dual channels of 24 filter suppression per stereo channel of the mixing console subgroup. 1. Connect the stereo output inserts of the mixer to the inputs of the AFS 224. 2.
AFS 224 Operation Applications Guide Application 4- Connected Inline with the Outputs of a Mixer This application is ideal for dedicated feedback suppression on the outputs of a mixing console. This application provides the user with dual channels of 24 filters of feedback suppression per output channel of the mixing console. 1. Connect the outputs from the mixer to the inputs of the AFS 224. 2. Connect the outputs of the AFS 224 to the power amps. 3. Apply power to the mixer and amplifiers.
Inputs RF Filter Input TYPE IV™ 11 AFS 224 User Manual 386 User Manual Mode Live Filter Lift Type Bypass CLIP Detect A/D Programmable Logic Micro Processor DSP Input meter Mode Live Filter Lift Type Bypass Filter meter LEDs D/A RF Filter Outputs AFS 224 Block Diagram Operation Block Diagram AFS 224 Block diagram ®
AFS 224 Operation Specifications Specifications Analog Inputs: Number of Inputs: Connectors: Type: Impedance: Max input line level: CMRR: 2 Female XLR and 1/4” TRS Electronically balanced/unbalanced, RF filtered Balanced 50kΩ, Unbalanced 25kΩ +20dBu >40dB, typically >55dB @ 1kHz Analog Outputs: Number of Outputs: Connectors: Type: Impedance: Max Output Level: 2 Male XLR and 1/4” TRS Electronically balanced/unbalanced, RF filtered Balanced >120Ω, unbalanced >60Ω +20dBu A/D Performance: Type: Dynamic R
® A Harman International Company 8760 South Sandy Pkwy. Sandy, Utah 84070 Phone: (801) 568-7660 Fax: (801) 568-7662 Questions or comments E•mail us at: customer@dbxpro.com or visit our World Wide Web home page at: www.dbxpro.
