dbx Pro AFS 224 User Manual

User Manual

Dual Channel Advanced Feedback Suppression Processor

AFS

™

224

WARNING FOR YOUR PROTECTION

READ THESE INSTRUCTIONS:

KEEP THESE INSTRUCTIONS

HEED ALL WARNINGS

FOLLOW ALL INSTRUCTIONS

DO NOT USE THIS APPARATUS NEAR WATER

CLEAN ONLY WITH A DRY CLOTH.

DO NOT BLOCK ANY OF THE VENTILATION OPENINGS. INSTALL IN ACCORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS.

DO NOT INSTALL NEAR ANY HEAT SOURCES SUCH AS RADIATORS, HEAT REGISTERS, STOVES, OR OTHER APPARATUS (INCLUDING AMPLIFIERS) THAT PRODUCE HEA

ONLY USE ATTACHMENTS/ACCESSORIES SPECIFIED BY THE MANUFACTURER.

UNPLUG THIS APPARATUS DURING LIGHTNING STORMS OR WHEN UNUSED FOR LONG PERIODS OF TIME.

Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A grounding type plug has two blades and a third grounding prong. The wide blade or third prong are provided for your safety. If the provided plug does not fit your outlet, consult an electrician for replacement of the obsolete outlet.

Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.

Use only with the cart stand, tripod bracket, or table specified by the manufacture, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.

Refer all servicing to to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.

POWER ON/OFF SWITCH: For products provided with a power switch, the power switch DOES NOT break the connection from the mains.

MAINS DISCONNECT: The plug shall remain readily operable. For rack-mount or installation where plug is not accessible, an all-pole mains switch with a contact separation of at least 3 mm in each pole shall be incorporated into the electrical installation of the rack or building.

FOR UNITS EQUIPPED WITH EXTERNALLY ACCESSIBLE FUSE RECEPTACLE: Replace fuse with same type and rating only.

MULTIPLE-INPUT VOLTAGE: This equipment may require the use of a different line cord, attachment plug, or both, depending on the available power source at installation. Connect this equipment only to the power source indicated on the equipment rear panel. To reduce the risk of fire or electric shock, refer servicing to qualified service personnel or equivalent.

This Equipment is intended for rack mount use only.

SAFETY INSTRUCTIONS

NOTICE FOR CUSTOMERS IF YOUR UNIT IS EQUIPPED WITH A POWER CORD.

WARNING: THIS APPLIANCE MUST BE EARTHED.

The cores in the mains lead are coloured in accordance with the following code:

GREEN and YELLOW - Earth BLUE - Neutral BROWN - Live

As colours of the cores in the mains lead of this appliance may not correspond with the coloured markings identifying the terminals in your plug, proceed as follows:

• The core which is coloured green and yellow must be connected to the terminal in the plug marked with the letter E, or with the earth symbol, or coloured green, or green and yellow.

• The core which is coloured blue must be connected to the terminal marked N or coloured black.

• The core which is coloured brown must be connected to the terminal marked L or coloured red.

This equipment may require the use of a different line cord, attachment plug, or both, depending on the available power source at installation. If the attachment plug needs to be changed, refer servicing to qualified service personnel who should refer to the table below. The green/yellow wire shall be connected directly to the units chassis.

WARNING:If the ground is defeated, certain fault conditions in the unit or in the system to which it is connected can result in full line voltage between chassis and earth ground. Severe injury or death can then result if the chassis and earth ground are touched simultaneously.

The symbols shown above are internationally accepted symbols that warn of potential hazards with electrical products. The lightning flash with arrowpoint in an equilateral triangle means that there are dangerous voltages present within the unit. The exclamation point in an equilateral triangle indicates that it is necessary for the user to refer to the owner’s manual.

These symbols warn that there are no user serviceable parts inside the unit. Do not open the unit. Do not attempt to service the unit yourself. Refer all servicing to qualified personnel. Opening the chassis for any reason will void the manufacturer’s warranty. Do not get the unit wet. If liquid is spilled on the unit, shut it off immediately and take it to a dealer for service. Disconnect the unit during storms to prevent damage.

IMPORTANT SAFETY INSTRUCTIONS

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

ATTENTION: WARNING:

SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE

RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR

TO REDUCE THE RISK OF FIRE OR ELECTRIC

CONDUCTOR

LIVE

NEUTRAL

EARTH GND

WIRE COLOR

Normal Alt

BROWN

BLUE

GREEN/YEL

BLACK

WHITE

GREEN

U.K. MAINS PLUG WARNING

A molded mains plug that has been cut off from the cord is unsafe. Discard the mains plug at a suitable disposal facility. NEVER UNDER

ANY CIRCUMSTANCES SHOULD YOU INSERT A DAMAGED OR CUT MAINS PLUG INTO A 13 AMP POWER SOCKET. Do not use the

mains plug without the fuse cover in place. Replacement fuse covers can be obtained from your local retailer. Replacement fuses are 13 amps and MUST be ASTA approved

to BS1362.

IMPORTANT SAFETY INSTRUCTIONS

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 interfer-

ence received, including interference

that may cause undesired operation.

Operation of this unit within significant

electromagnetic fields should be avoided.

• use only shielded interconnecting

cables.

DECLARATION OF

CONFORMITY

Manufacturer’s Name: dbx Professional Products Manufacturer’s Address: 8760 S. Sandy Parkway

Sandy, Utah 84070, USA

declares that the product:

Product name: dbx AFS 224 Note: Product name may be suffixed by the

letters-EU.

Product option: None

conforms to the following Product Specifications:

Safety: IEC 60065 (1998)

EMC: EN 55013 (1990)

EN 55020 (1991)

Supplementary Information:

The product herewith complies with the requirements of the Low Voltage Directive 72/23/EEC and the EMC Directive 89/336/EEC as amended by Directive 93/68/EEC.

Vice-President of Engineering 8760 S. Sandy Parkway Sandy, Utah 84070, USA Date: June 9, 2003

European Contact: Your local dbx Sales and Service Office or

Harman Music Group 8760 South Sandy Parkway Sandy, Utah 84070 USA Ph: (801) 566-8800 Fax: (801) 568-7583

Ta b le of Contents

AFS 224

Ta b le 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........................................2

User Setup...............................................................3

Applications ............................................................7

Block Diagram......................................................10

Specifications ........................................................11

AFS 224 User Manual

Table of Contents

AFS 224 Operation

AFS 224

Introduction

AFS 224 User Manual

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. The AFS 224 is an absolute must for any live sound application.

Ten and twelve filter feedback elimination processors have become the de facto standard, but the engineering staff at dbx have never been content residing in the neighborhood of the status quo. So, to raise the bar once again, they went out and developed a dedicated feedback suppression processor that offers up to 24 filters per channel with widths as narrow as 1/80 of an octave. To achieve these staggering numbers dbx utilized their patent-pending AFS technology that had previously only been available in the upper echelon line of products and made it available in this stand-alone processor. In addition to the plethora of feedback suppression filters available, the AFS 224 also offers selectable modes, live filter lift, and types of filtration, which are all readily available via the intuitive user interface front panel. This manual will be your guide to understanding the full functionality of the powerful AFS 224 series.

The dbx AFS 224 provide the user with the following features:

• dbx’s patent-pending Advanced Feedback Suppression (AFS™)

technology

• 24 Programmable Filters per Channel

• Stereo or Dual Independent Channel Processing

• Live and Fixed Filter Modes

• Selectable Filter Lift Times

• Application-specific filter types include:Speech; Music Low, Med and High

• Input Channel Metering

• 24 Segment Filter Metering per Channel

• XLR and TRS Electronically Balanced Input and Outputs

The AFS 224 Advantage

Key features that make the AFS 224 are its Fixed and Live modes of operation, as well as the units Filter Lift capabilities. The Live Mode of operation continuously updates filter placement which provides flexibility during a performance. The Filter Lift feature automatically removes filter assignments that are no longer necessary, which in turn, maximizes sonic integrity.

The AFS 224 allows the user to optimize the elimination of feedback. In the past, graphic equalizers were used to eliminate feedback from a system. This was an acceptable method for eliminating feedback, but when this method was precision tested, the result clearly showed that a single 1/3 octave EQ slider was removing approximately half of the signal power. With the AFS, the unit removes the feedback automatically and the proprietary, precision AFS filters remove only a fraction of the frequency spectrum. The diagram on the following page shows AFS as opposed to competitive feedback eliminators and conventional graphic EQs:

Defining the AFS 224

INTRODUCTION

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