JL Audio Fathom f212 User Manual

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f212

Owner’s Manual

IMPORTANT SAFETY INSTRUCTIONS

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS PRODUCT TO RAIN OR MOISTURE.

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE AMP PANEL OR SPEAKER. NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.

1)Read the Instructions — All safety and operating instructions should be read before the subwoofer is operated.

2)Retain the Instructions — The safety and operating instructions should be retained for future reference.

3)Heed Warnings — All warnings on the subwoofer and in the operating instructions should be followed.

4)Follow Instructions — All operating and use instructions should be followed.

5)Water and Moisture — The subwoofer should NOT be used near water – for example, near a bathtub, washbowl, sink, laundry tub, in a wet basement, near a swimming pool, etc.

6)Ventilation — The subwoofer should be situated so that its location or position does not interfere with its proper ventilation. For example, the subwoofer should not be situated on a bed, sofa, rug, or similar surface that may block airflow over the heatsink fins. If placing the subwoofer in a“built-in”installation, ensure that airflow to the heat sink at the rear of the subwoofer is not impeded. Do not cover the subwoofer heatsink with tablecloths, curtains, etc.

9)Heat and Flames — The subwoofer should be situated away from heat sources such as radiators, heat registers, stoves, fireplaces, or other devices which produce heat. Do not place candles on top of or near the subwoofer.

10)Power sources — The subwoofer should only be connected to a power supply of the type described in the operating instructions or as marked on the subwoofer.

11)Power Cord Protection Power-supplycords should be routed so that they are not likely to be walked on or pinched by items placed upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point where they exit the subwoofer.

The lightning flash with arrowhead symbol, within an equilateral triangle, is intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons.

The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance instructions in the literature accompanying the product.

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12)Cleaning — The subwoofer should be cleaned only as recommended in the operating instructions.

13)Nonuse Periods — The power cord of the subwoofer should be unplugged from the outlet when the subwoofer is left unused for long periods of time.

14)Lightning and Power Surges — We recommend that you disconnect the subwoofer from the electrical outlet during electrical storms and/or recurring power interruptions to prevent damage due to power surges.

15)Object or Liquid Entry — Care should be taken so that objects do not fall into and liquids are not spilled onto the subwoofer enclosure. Do not expose the subwoofer to dripping or splashing from liquids. Do not place objects filled with liquids on top of, or near the subwoofer. For example: flower vases, beverages,liquid-fueledlamps, etc.

16)Damage Requiring Service — The subwoofer should be serviced by qualified service personnel when:

a.the power-supplycord or plug has been damaged

b.objects have fallen or liquid has been spilled into the subwoofer

c.the subwoofer has been exposed to rain

d.the subwoofer does not appear to operate normally or exhibits a marked change in performance

e.the subwoofer has been dropped or the cabinet has been damaged

f.the subwoofer driver’s cone and/or suspension has been physically damaged

17)Servicing — The user should not attempt to service the subwoofer beyond what is described in the operating instructions. All other servicing should be referred to qualified service personnel.

18)Overloading — Do not overload wall outlets, extension cords, or outlet strips as this can result in a risk of fire or electric shock.

19)Grounding — This subwoofer is supplied with athree-prong,grounded power cord. Precautions should be taken so that the grounding means of the subwoofer are not defeated. Defeating the grounding prong on the subwoofer power cord could increase the risk of electric shock and could result in permanent damage to the subwoofer’s electronics.

THIS SUBWOOFER IS CAPABLE OF PRODUCING VERY HIGH SOUND WARNING PRESSURE LEVELS. PLEASE EXERCISE RESTRAINT IN ITS OPERATION TO

PROTECT YOUR HEARING FROM PERMANENT DAMAGE.

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FCC COMPLIANCE STATEMENT

NOTE: This equipment has been tested and found to comply with the limits of Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

-Reorient or relocate the receiving antenna.

-Increase the separation between the equipment and receiver.

-Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

-Consult the dealer or an experienced radio/TV technician for help.

TABLE OF CONTENTS

Important Safety Instructions: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Introduction:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Product Overview:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Placing your Fathom in Your Listening Room: . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10Unpacking your Fathom: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Front Control Panel Layout:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Rear Control and Connector Panel Layout: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Front Panel Controls in Detail: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14-17Connecting yourFathom(s): . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-25Recommended SetupProcedure: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26-30Frequently Asked Questions: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Cleaning Your Fathom:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Troubleshooting: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Limited Warranty / Service Information: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Specifications:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

INTRODUCTION

Congratulations on your purchase of a JL Audio Fathom powered subwoofer system. This product has been critically engineered to deliver exceptional performance in your home theater or audio system for many years to come.

As a company, we are intensely committed to core research into high-performanceloudspeaker and amplifier technologies. JL Audio’s longexcursion subwoofer driver designs are widely considered as reference standards for linear behavior and high output. We have also focused our efforts to create powerful amplifier andsignal-processingtechnologies specifically aimed at delivering exceptionallow-frequencyperformance. YourFathom combines these core disciplines within a compact, beautifully crafted package to deliver an unparalleled listening experience.

JL AUDIO TECHNOLOGIES INCLUDED IN FATHOM SUBWOOFERS

DMA-OptimizedMotor System

DMA is JL Audio’s proprietary Dynamic Motor Analysis system aimed at improving dynamic motor behavior. As a result of DMA optimization, loudspeaker motors remain linear in force over an extreme range of excursion and also maintain a highly stable fi xed magnetic field over a wide power range. This leads to vastly reduced distortion and faithfully reproduced transients... or put simply: tight, clean, articulate bass.

OverRoll™ Surround

(U.S. Patent #5,687,247 and #5,949,898)

The OverRoll™ surround spans over the driver’s mounting flange, utilizing

available diameter wasted in conventional speakers. This allows the use of the wider roll necessary to control high-excursionswithout sacrificing precious cone area.

W-Cone™(U.S. Patent #6,496,590)

The W-Cone™is aunit-bodycone assembly that delivers astonishing cone stiffness with minimal mass.

Floating-Cone™Attach Method (U.S. Patent #6,501,844)

This assembly technique ensures proper surround geometry in the assembled speaker for better excursion control and dynamic voice coil alignment.

Plateau-ReinforcedSpider Attachment (U.S. Patent #6,118,884)

This high-integritysuspension attachment relieves stress from the spider material athigh-excursionsfor enhanced reliability.

Elevated Frame Cooling Technology (U.S. Patent #6,219,431 and #6,229,902)

Delivers cool air, through slots directly above the top-plate,to the voice coil of the speaker. This enhances power handling and sound quality by minimizing dynamic parameter shifts and power compression.

Radially Cross-DrilledPole Piece (U.S. Patent #6,243,479)

This innovative venting system greatly enhances thermal dissipation and power handling by directing air flow onto the voice coil former, working in conjunction with the Elevated Frame technology.

High-DampingFeedback Circuit (U.S. Patent #6,441,685)

This proprietary, discrete control circuit design allows our Class D switching amplifiers to maintain an excellent damping factor for improved transient behavior and fidelity.

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We sincerely thank you for your purchase and invite you to read this manual thoroughly in order to achieve the highest level of performance with your Fathom subwoofer system. Enjoy.

PRODUCT OVERVIEW

JL Audio Fathom subwoofers combine astate-of-the-art

JL Audio subwoofer driver and electronics/amplifier package within a highly optimized enclosure to deliver an exceptional listening experience in your home theater or home audio system.

The subwoofer driver in your Fathom subwoofer system is capable of outstanding linear excursion without distress or audible distortion. Thisreference-qualitydriver enables yourFathom to reproduce powerful lowfrequency events with stunning impact and unprecedented accuracy. Derived from JL Audio’s legendary W7 design platform, theFathom f212 drivers offerpeak-to-peakexcursion capabilities well in excess of 3 inches (76 mm), to comfortably handle the dynamics of the most demanding program material.

To get the most from this long excursion driver platform, prodigious amounts of controlled power are needed. Our electronics engineering team conducted

an intense analysis of typical program material and its dynamic demands in order to balance current draw and actual output power requirements relative to the system’s impedance characteristics. After careful study, a pair of precisely engineered switching amplifiers employing patented feedback technology were created. The advanced amplifier design in the F212 is capable of unclipped output voltages equivalent to 3000 watts of RMS power when referenced to the nominal loudspeaker impedance, allowing us to take full advantage of each driver’s full excursion envelope.

The beautiful cabinet enclosing the workings of your Fathom is also the result of careful engineering. To contain the pressures created by the Fathom driver, we utilized solid, CNC-cut,MDF material with extensive internal bracing features and advanced assembly techniques.

Your listening room is the other enclosure that affects the way your bass will sound. All rooms create a specific sonic signature, which must be effectively managed to achieve well-balancedlow frequency performance. To aid in this process, the Fathom includes an extensive set of signal processing tools aimed at optimizing your Fathom’s performance within your listening space. These features include JL Audio’s exclusive Automatic Room Optimization system.

As you can see from this brief introduction, there is a lot of technology in this compact subwoofer. The contents of this manual will explain the features, guide you through the setup and tuning of your Fathom subwoofer and help you achieve your ultimate low-frequencylistening experience.

If you require assistance, we urge you to contact your authorized

JL Audio retailer for expert setup advice and service.

IMPORTANT! IT IS A VERY GOOD IDEA TO READ THE NEXT SECTION IMPORTANT BEFORE UNPACKING YOUR FATHOM. UNPACKING THE SUBWOOFER NEAR

ITS FINAL LOCATION IS RECOMMENDED.

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PLACING YOUR FATHOM IN YOUR LISTENING ROOM:

Your listening room or theater is an integral part of your sound reproduction system. The physical dimensions of the room and its furnishings, materials, doors and windows play an important role in defining how your system sounds.

When you place a sound source in an enclosed rectangular space, “standing waves” are created, resulting from the relationship between the sound’s wavelength and your room’s dimensions. In other words, standing waves result from sound energy that is trapped in the room as it bounces back and forth between opposing walls. Standing waves in the room create acoustic peaks and dips where the sound is either louder or softer, based solely on your physical position in the room. Energy also “builds up” at the room’s boundaries, creating exaggerated bass response at certain frequencies. These fundamental room resonances are called room “modes.”

The moral of this mode story is to try and avoid seating positions in standing wave peak or dip regions. It is highly recommended that you place your listening chairs in areas where modal peaks and dips are moderate and do not reinforce one another. The two most obvious areas to avoid are those near the exact center of the room and those close to any of the room’s walls.

Just as your listening seat can be in a peak or dip region, so can your subwoofer. When placed in a room corner, a subwoofer maximally excites the room’s mode structure, creating the strongest output with the fewest dips. When the subwoofer is pulled away from a corner or wall, the room modes are excited less, which can alter the sound at your listening seat.

Be sure to experiment with both your listening seat position and subwoofer position to find the best solution. Careful experimentation usually leads to a superior sounding system. Use our setup suggestions (illustrated on the opposing page and the following pages) to get you started.

If you cannot avoid placing your sofa against the back wall or your subwoofer in a less than optimal position, all is not lost. Your Fathom’s Automatic Room Optimization (A.R.O.) System can dramatically improve these less-than-idealsituations.

We recommend that you begin by placing your Fathom in the front of the room, near the front left or right speaker. Placing it directly in the front corner of the room will produce the maximum number of peaks and the minimum number of dips in the bass response. This can be advantageous because the Fathom’s A.R.O. system can correct the primary peak very effectively, whereas dips in response cannot be corrected via equalization. Dips in response can only be minimized via careful subwoofer and listener placement.

Placing the Fathom near solid walls will reinforce bass response and pulling it away from solid walls will decrease bass. Increasing the distance between the subwoofer and the walls may help to smooth upper bass response in some rooms.

We recommend that you avoid placing the Fathom near windows to prevent rattling and sound transmission to the outside world.

If you are planning to install your Fathom inside a cabinet, please refer to the guidelines on page 8.

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Recommended Subwoofer Placement Options for One Fathom

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SPECIAL CONSIDERATIONS FOR BUILT-ININSTALLATIONS

Fathom subwoofers are designed to be “built-in”friendly. All typically needed controls are located on the front panel above the woofer. A Fathom can be easily integrated into custom cabinetry by following a few simple guidelines.

1)Allow 4 inches (10 cm) of clear space behind the Fathom’s amp panel for adequate cooling and connector clearance.

2)On all other sides (except the bottom), allow at least 2 inches (5 cm) clearance for adequate ventilation.

3)While the Fathom generally runs only warm during spirited operation, we do recommend that adequate heat vents are included in any custom cabinet which encloses theFathom. Pairs of 3 inch (7.5 cm) diameter vents over the full cabinet height (8 vents total, see diagram) will allow cool air to circulate over the amp panel of your Fathom f212 subwoofer system keeping it cool and happy.

4)Your Fathom f212 subwoofer is capable of moving substantial quantities of air. If the front of the f212 is covered by a custom grille, the grille must have AT LEAST 170 square inches (1100 sq. cm.) of vent area. This grill area is equal to the woofer cone area for the f212 and will ensure that the Fathom’s output is not choked by the custom cabinet.

Rear-viewof cabinet install:

 

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Using Two Fathoms

Recommended Subwoofer Placement Options for Two Fathoms

When using two Fathoms, try placement near the front corners of the room, at diagonally-oppositecorners of the room, or at the center points of opposing walls as shown at right.

Experimentation with subwoofer and listener placement is recommended to achieve the best results – the benefits can be substantial.

High-resolutionmeasurements and professional system calibration are recommended for the best possible results & system performance.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Recommended Subwoofer Placement Options for Three Fathoms

Recommended Subwoofer Placement Options for Four Fathoms

Using Three or Four Fathoms

Research indicates that the smoothest bass response for a large listening area can be achieved using four subwoofers, placing one at

the midpoint of each of the four walls (although using two or three subwoofers can be almost as good).

Experimentation with subwoofer and listener placement is recommended to achieve the best results – the benefits can be substantial.

High-resolutionmeasurements and professional system calibration are recommended for the best possible results & system performance.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Unpack this box close to where the subwoofer will be placed. The subwoofer is PACKED upside down.This box must be flipped over CAREFULLY to remove the subwoofer and minimize effort.

IMPORTANT

IMPORTANT

UNPACKING YOUR FATHOM

Now that you have determined your Fathom’s position in the room, you can proceed with unpacking it near its intended location.

D

C

A

B

IMPORTANT: DUE TO THE WEIGHT OF THE FATHOM SUBWOOFER, PLEASE EXERCISE CAUTION WHILE UNPACKING AND POSITIONING IT TO PREVENT INJURY. IF POSSIBLE, ENLIST THE HELP OF A SECOND PERSON TO FACILITATE THE PROCESS. TO MINIMIZE THE RISK OF INJURY, BEND YOUR KNEES AND LIFT WITH YOUR LEGS, NOT YOUR BACK.

Detailed instructions on unpacking the subwoofer:

1.Place the carton on the floor near its intended location in the room.

2.Open the top of the carton (observe markings on carton) and remove the manual, calibration microphone and power cord.

3.Temporarily remove the split-foampacking inserts.

4.Untie and loosen the protective cloth cover to make later removal easier (do not remove at this time). When you open the cloth cover, you are looking at the bottom of the subwoofer cabinet.

5.Replace the split-foaminserts to protect the subwoofer’s cabinet while unpacking.

6.Gently flip the box on its side, folding back the carton flaps to the outside.

7.Holding the carton flaps back, gently flip the carton onto its top (open end).

8.Pull the carton straight up until it clears the subwoofer and place to one side.

9.Remove the one-piecefoam insert and place in the carton.

10.Remove the plastic bag and place in the carton.

11.Tilt the subwoofer forward (toward its grille) to remove the rear split-foaminsert first. Then tilt the subwoofer in the opposite direction (towards its amplifier panel) to remove the remainingsplit-foaminsert. Place bothsplit-foaminserts in the carton.

12.Remove the protective cloth cover and place in the carton.

IMPORTANT! PLEASE RETAIN ALL PACKAGING FOR SAFE TRANSPORTATION OF THE SUBWOOFER AND FOR ANY FUTURE SERVICE NEEDS.

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Front Control Panel

The labeled Figure below depicts the front control panel of a Fathom f212 subwoofer.

 

 

 

 

A.R.O.

 

Level Mode

Lights

 

 

 

 

LP freq. (Hz) phase (deg.)

 

 

 

 

 

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page 15

page 16

page 16

page 17

 

 

Power

 

Input Mode

 

 

Master Level

 

 

LP Filter

 

e.l.f. trim (dB)

Polarity

 

 

page 14

 

page 15

 

 

page 16

 

 

 

 

page 16

 

page 17

 

page 17

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 12

| Fathomf212

Rear Controls and Connectors

The labeled Figure below depicts the rear panel of a Fathom f212 subwoofer.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unbalanced

Output to

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Inputs

 

 

 

 

 

 

 

Slave Connector

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

page 19

 

 

 

 

 

 

 

 

 

 

 

 

page 21

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IEC-StyleAC

 

 

 

 

 

 

Input Mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Balanced Inputs

 

Connector

 

 

 

 

 

 

Switches

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

page 18

 

page 21

 

 

 

 

 

 

page 20

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

| Fathomf212

Page 13

FRONT PANEL CONTROLS IN DETAIL

Power Switch

The “Power” switch determines the operational readiness of the Fathom subwoofer and should be the only switch used to turn the Fathom on and off. Do not use a power strip switch, switched outlet or any other external switch as these may result in undesirable and potentially damaging transient pops. Do not unplug the Fathom’s AC power cord while the unit is turned on.

The power switch has three positions:

“On”: The Fathom is fully powered at all times. Front panel lights are on unless they have been turned off via the “Lights” switch.

“Off ”: The Fathom’s internal power amplifier is powered down. In this state, a negligible current draw will exist for operating the main power relays. All front panel lights are off .

“Auto”: The Fathom will power up its internal amplifier when an audio signal is present at any of its inputs and will power down the internal amplifier if no signal has been detected at its inputs for thirty (30) minutes. When dormant, the Fathom will draw a very small amount of current (< 5 watts) to power itssignal-sensingcircuitry.

Front panel lights will turn off when the Fathom powers down and light when the Fathom powers up (unless they have been turned off via the “Lights” switch).

In the unlikely event that the Auto feature is not sensitive enough for a particular system, use a Y-cableadaptor to split the incoming signal into both RCA or XLR inputs on the Fathom. This will increase the input sensitivity by 6 dB. Please be aware that if the Auto sensitivity is too high or if there is significant noise on the input cable, the Fathom may not turn off as desired. If this happens, remove theY-cableadaptor or look for the noise source in the upstream components.

Automatic Room Optimization (A.R.O.)

A powerful feature of the JL Audio Fathom subwoofers is their innovative Automatic Room Optimization (A.R.O.) technology. This one-touchsystem serves to eliminate the single largest acoustic response peak in your home theater at the main listening seat, greatly improving thein-roomlow-frequencyresponse. Calibration of the A.R.O. system is fully automated and takes only a few minutes to accomplish. Please consult the next section of this manual for details on how to use the A.R.O. system

Using the included JL Audio calibration microphone, the A.R.O. calibration procedure takes less than three minutes. In brief, you will connect the included microphone to the “Calibration Mic.” input, press the Calibrate button, and then hold the microphone at ear height in your main listening seat during the test. A series of tones will be played through the Fathom subwoofer, and the room response will be automatically measured, analyzed and equalized to eliminate the single largest acoustic room response peak at your listening seat. For detailed instructions on the A.R.O. setup procedure, refer to pages 29-30.

Calibration Mic. Input

This input is for connecting the supplied JL Audio calibration microphone to the Fathom subwoofer. Connect one end of the supplied cable to the microphone and the other end to this jack prior to using the A.R.O. system. The A.R.O. system is specifically calibrated to this microphone and its connection scheme is specific to the supplied microphone. The calibration sequence will not operate when a different microphone is connected or if no microphone is connected.

IMPORTANT

Page 14

| Fathomf212

Demo Button

The Demo button triggers a 20 second long tone sequence that briefly demonstrates the signals used during A.R.O. calibration. The Demo function is useful for showcasing the output capability of the Fathom and to verify that the Fathom (or multiple Fathoms) are operational during system troubleshooting.

To activate the demonstration sequence, press and hold the “Demo” button for approximately 2 seconds (this built in delay helps prevent accidental activation). Pressing and holding the “Demo” button will activate the demo sequence even if the A.R.O. defeat function is active (see below.) Once the demonstration sequence is complete, the Fathom will return to its previously set operating condition.

Defeat Button

The “Defeat” button turns off or “defeats” the A.R.O. calibration system and equalizer. Use this feature when you want to be sure that the A.R.O.’s equalization is not in the signal chain. You can also use the “Defeat” button to audition both the normal and the A.R.O. optimized settings in your home theater room. This is a great way to audibly verify what effect the A.R.O. has in your room.

If “Demo” or “Calibrate” is pressed while the defeat function is active, “Defeat” is automatically canceled. No other front panel controls will alter the A.R.O. Defeat state.

Calibrate Button

The Calibrate button activates the ARO test sequence. The calibration routine will not start unless the supplied JL Audio test microphone is plugged into the Fathom subwoofer. Once the calibration routine is complete, the green light in the center of the “Calibrate” button will light and remain illuminated. These settings are stored by the Fathom and will remain in memory even if power is disconnected.

During the ARO test sequence the Calibrate button’s green LED will alert the user to two special conditions:

1.“Subwoofer level too low for A.R.O. calibration” via slow blinking, approximately one blink per second

2.“Subwoofer level too high for A.R.O. calibration”, approximately three blinks per second.

Input Mode Indicators

The Input Mode indicator LEDs show the input mode, either “Master” or “Slave”, selected by the switch on the Fathom’s back panel (unless the “Lights” switch is set to “off”). For further details, see page 20.

Level Mode

The two-positionLevel Mode switch allows you to select between the following modes:

“Reference”

In this mode, the Master Level control knob has no effect on the Fathom’s output level. Use this setting if you will primarily be controlling the subwoofer level via your receiver or preamplifier/processor. For those of us with small children or overenthusiastic teenagers, this mode of operation will prevent direct manipulation of the Master Level.

“Variable”

In this mode, the Master Level control knob determines the output level of the Fathom subwoofer. This mode is also useful when level matching the Fathom subwoofer to a pair of stereo speakers in a two-channelsystem. Variable level operation is needed for proper A.R.O. calibration.

| Fathomf212

Page 15

Master Level Knob

The Master Level Knob is used to control the output level of the Fathom when the Variable Level mode is selected on the front control panel.

When rotated fully counter clockwise, the Fathom’s output will be fully muted. When at the “0” or straight up position, the Variable gain level matches the Reference level setting. When turned fully clockwise, the Fathom’s output level is 15 dB higher than the Reference setting.

Lights

The “Lights” selector switch allows the user to select one of three indicator light modes.

“Off” turns off all of the front panel LED’s at all times.

“Dim” sets all of the front panel LEDs to a low brightness level when the Fathom is turned on.

“On” sets all of the front panel LEDs to full brightness level when the Fathom is turned on.

IMPORTANT: WHEN TROUBLESHOOTING OR CALIBRATING THE A.R.O. FEATURE, MAKE SURE THAT THE “LIGHTS” SWITCH IS SET TO “DIM” or “ON.”

LP Filter

The Low Pass (LP) Filter selector switch determines the operating mode of the Fathom’s built-inlow pass filter.

“Off” defeats the low pass filter, completely removing this circuit from the signal path.

“12 dB” sets the roll off slope of the low pass filter to a 12 dB per octave slope (Butterworth alignment).

“24 dB” sets the roll off slope of the low pass filter to a 24 dB per octave slope(Linkwitz-Rileyalignment).

The 24 dB setting more aggressively attenuates high frequencies above the LP Frequency setting (see below). If you are using the Fathom’s built-inlow pass filter, experiment with the LP Filter slope setting to achieve the best transition to your satellite speakers. If you prefer to use the filters and bass management features in your receiver or preamplifier, defeat the

on-boardfilter by selecting the “Off ” position.

LP Freq

The Low Pass (LP) Frequency selector knob allows the user to choose the rolloff frequency of the Fathom’s internal low pass filter. The frequency is variable between 30 Hz (full counter-clockwise)to 130 Hz (full clockwise). This knob does not affect the input signal in any way if the LP Filter switch is set to “Off ”. 80 Hz is a commonly used filter frequency and usually serves as a good starting point for adjustments.

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E.L.F. Trim

The Extreme Low Frequency (“e.l.f. trim”) knob allows the user to apply a certain amount of signal equalization at 25 Hertz (extremely low bass). At full counterclockwise rotation, the signal at 25 Hz is cut by 12 dB. At “0” the

equalizer is set flat for zero contribution to the signal. At full clockwise rotation, the signal at 25 Hz is boosted by 3 dB.

The E.L.F. Trim feature is useful for tailoring the Fathom’s very low frequency output for your particular room. Adding some boost can make certain material more exciting. Using the cut function can help to compensate for room or boundary gain in the low frequencies. Room boundaries and the room’s finite (limited) size naturally cause very low frequencies to be boosted relative to

other parts of the signal. As such, using the E.L.F. Trim feature to cut the lowest frequencies can help to tame “bloat” or unnatural sounding low bass in small to medium sized rooms (and can also reduce unwanted vibrations in the room or throughout the house).

Polarity

The Polarity switch allows the user to select between normal (0 deg) and reversed (180 deg) signal polarity. The Polarity switch will primarily affect the small frequency range around the crossover point between your subwoofer and satellite speakers.

Unlike the Phase control, which effectively adds time delay, the Polarity switch produces an instantaneous reversal of the signal’s amplitude peaks. For example, if at a given reference point a sine wave has an amplitude peak, by flipping the phase switch you instantly convert that peak into a trough or amplitude dip. Because the effect of the Polarity switch is immediate, it

compliments the operation of the Phase control and cannot be replaced by it. When placing your Fathom in the room, experiment with the Polarity switch

before adjusting the “Phase” control. Either position of the Polarity switch may provide a smoother transition between your Fathom subwoofer and the satellite speakers. Use source material with good mid and upper bass content for evaluation.

Phase

The Phase control knob allows the user to adjust the “timing” of the subwoofer output relative to the main speakers. The Phase control will primarily affect the small frequency range around the crossover point between your subwoofer and satellite speakers. The Phase control’s labels are referenced to 80 Hz since this is the most common crossover point between satellite speakers and a subwoofer. Phase settings between 0 degrees (full counter-clockwiserotation) and 280 degrees (full clockwise rotation) are possible.

Speaker, subwoofer, and listening seat positions vary greatly in home theater installations. Since physical positioning of speakers relative to the room boundaries and each other greatly affects the perceived quality of sound output, sometimes it is helpful to delay the subwoofer output. This is exactly what occurs when you turn the Phase control beyond 0 degrees.

Once your Fathom has been placed in your listening room to give you the smoothest overall sound and after you have determined the optimum “Polarity” switch position (see preceding section), experiment with the position of the Phase control. Using familiar source material with good mid and upper bass content, adjust the Phase control and listen for better defined mid-bassand a smoother transition between the subwoofer and satellite speaker systems. If no single setting sounds better than another, leave the Phase control at 0 degrees.

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CONNECTING YOUR FATHOM

Balanced Inputs

If your home-theaterreceiver or preamplifier/processor provides balanced outputs, the Fathom’s balanced inputs are the preferred connection. Balanced connections are used extensively in professional studios and sound reinforcement applications for a number of very good reasons. Besides ensuring proper grounding between components, balanced signal transmission is designed to cancel induced cable noise from the surrounding environment (particularly important with long cable runs). The bottom line is that your system will be far less likely to exhibit humming or other extraneous noises if you use balanced connections.

The Fathom subwoofers feature individual left and right balanced input connections with XLR “combo” jacks. These special jacks accept either a three-pinmale XLR connector or a“tip-ring-sleeve”(TRS)1/4-inch(6.3 mm) connector for compatibility with a wide range of equipment.

For systems with a mono subwoofer or “LFE” channel connection, only the jack labeled “Left or Mono” will be used. This applies to most modern multichannel receivers and preamplifier/processors. Separate left and right input jacks are provided for systems without a dedicated mono subwoofer connection. This typically applies to two-channelaudio equipment.

Appropriate balanced cables are available from your JL Audio dealer and are not included with the Fathom.

Technical Notes:

Do not use the balanced inputs with unbalanced signals via adaptors.

The unbalanced inputs of the Fathom are optically isolated and preferable in situations where only an unbalanced signal source is available.

Input connectors are configured according to Audio Engineering Society recommendations for balanced signal cables as follows:

XLR Connection

Pin 1: Shield Pin 2: Positive Pin 3: Negative

TRS connection:

Tip: Positive Ring: Negative Sleeve: Shield

IMPORTANT: IF YOUR RECEIVER OR PREAMPLIFIER/PROCESSOR DOES NOT HAVE XLR OR1/4-INCHTRS BALANCED OUTPUTS, PLEASE REFER TO THE “UNBALANCED INPUTS” SECTION ON PAGE 19 FOR INPUT CONNECTION INFORMATION. DO NOT ATTEMPT TO CONNECT UNBALANCED OUTPUTS TO THE FATHOM’S BALANCED INPUTS VIA ADAPTORS.

The Left and Right inputs on the Fathom are internally summed to a single mono channel. Since the Fathom is inherently a “mono” or single channel device, you can use the Left and Right inputs for the master Fathom and then distribute the summed mono signal to additional slave Fathoms in the system.

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Unbalanced Inputs

The Fathom subwoofer features individual left and right unbalanced RCAtype input connectors. These are the most commonly used connectors for home audio applications and must be used if your receiver or preamplifier/processor does not provide balanced outputs. While unbalanced connections are not as noise-immuneas a balanced connection, Fathom subwoofers employ optical isolation on the unbalanced inputs to minimize the possibility of noise in your system.

For systems with a mono subwoofer or “LFE” channel connection, only the RCA-typejack labeled “Left or Mono” will be used. This applies to most

modern multi-channelreceivers and preamplifier / processors. Separate left and rightRCA-typeinput jacks are provided for systems without a dedicated mono subwoofer connection. This typically applies totwo-channelaudio equipment.

Technical Notes:

• When balanced outputs are not available on the signal source, you must use the RCA-typeunbalanced inputs. Fathoms feature optical isolation circuitry on the unbalanced inputs to minimize the likelihood of ground loop induced noise. Unbalanced input impedance is 10 kohms.

• Connections are industry-standardfor unbalanced signal cables as follows:

RCA-typeconnection:

Tip: Positive Sleeve: Negative

IMPORTANT: IF NOISE EXISTS AFTER CONNECTION, FATHOMS ALLOW

FOR GROUNDING OR ISOLATION OF THE UNBALANCED INPUTS. PLEASE IMPORTANT REFER TO THE “INPUT MODE SWITCHES” SECTION ON PAGE 20 OF THIS

MANUAL FOR FURTHER INFORMATION ON MINIMIZING NOISE.

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Input Mode Switches:

Two switches are located on the rear panel to control unbalanced signal grounding and master/slave operation.

“Grounded / Isolated” Switch

The “Grounded / Isolated” Input Mode switch affects only the unbalanced RCA inputs and is designed to facilitate a quiet, hum-freeconnection to your audio or home theater system. This feature is included to deal with the signal grounding issues often encountered in home theater systems when several components from different manufacturers are interconnected.

The Fathom ships with this switch in the “Isolated” mode. If, with all system components connected and turned on (but no source material playing), you hear a continuous low-frequencyhum through your Fathom, flip this switch to the “Grounded” position and evaluate the difference in the noise level. Use whichever switch position provides the least hum or noise.

IMPORTANT: PLEASE NOTE THAT CHANGING ANY COMPONENT IN THE OPTIMIZED SYSTEM (RECEIVER, AMPLIFIER, DVD PLAYER, CABLE OR SATELLITE BOX, ETC.) COULD ALTER THE SIGNAL GROUNDING SCHEME AND CAUSE HUM TO APPEAR IN YOUR PREVIOUSLY QUIET SYSTEM. IF YOU ADD OR CHANGE AN UPSTREAM COMPONENT IN YOUR HOME THEATER SYSTEM, YOU MAY NEED TO REVISIT THIS INPUT MODE SETTING ON THE FATHOM SUBWOOFER FOR OPTIMUM NOISE PERFORMANCE. CABLE & SATELLITE BOXES ARE PARTICULARLY TROUBLESOME IN THIS WAY.

Master / Slave Switch

The Fathoms are designed to easily accommodate the implementation of multiple subwoofers in your home theater system through a master/slave connection chain. This method allows you to utilize the signal processing features of one Fathom to centrally control multiple Fathoms in the room. Master/Slave functionality also makes it possible for the A.R.O. system to optimize the response of a multiple subwoofer installation.

The Fathom ships with this switch in the “Master” position. If you are using a single Fathom you will use the “Master” position and you need not concern yourself with this section any further.

If your installation incorporates two or more Fathoms, you will designate one Fathom as the “Master” and all others in the system as “Slave” subwoofers via the “Master/Slave” switch on the rear amplifier panel of each Fathom. LED’s on the front panel of the Fathom are provided to indicate whether the “Master” or “Slave” mode is selected for a given subwoofer.

From the Fathom operating in “Master” mode, the “Output to Slave” signal carries any signal processing selected on the Master Fathom (including the Master Level setting and A.R.O. processing) to further Fathoms operating in “Slave” mode. “Slave” subwoofer signal processing and level controls will be inoperable. In this mode, the user does not have to worry about level, crossover, and other settings for the slave subwoofers.

Technical Notes:

Selecting the “Slave” position defeats all user-definablesignal processing and the master level control. Because of this, there are some special situations in which you may want to operate a single Fathom in “Slave” mode. If you are utilizing outboard signal processing andlevel-matchingcontrols, activating the “Slave” mode will prevent anyone from affecting system parameters with the manual controls on the Fathom.

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