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 | Fathom 

IWS

Page 28

3) Polarity and Phase Adjustment

It is often helpful to have a second person operating these controls so that you 

can easily hear the changes from the primary listening seat. 

Listening to familiar source material (preferably music with good upper bass 

and midbass response), flip the “Polarity” switch from “0” to “180” and listen for 

differences.  The correct setting will sound most natural with the best upper bass 

punch and articulation.  If both sound similar, choose “0”.  

Once Polarity is set, use the same music material to audition different “Phase” 

control settings and choose the one that further enhances the upper and midbass 

response.  If you can’t hear a difference, set the control to “0.”

4) Extreme Low Frequency (e.l.f.) Trim

Use the “e.l.f. trim” control to adjust the extreme low bass extension of the 

Fathom IWS. This control allows -12 dB of cut or +3 dB of boost at 28 Hertz and is 

particularly useful when using a Fathom IWS (or two) in a small to medium sized 

home theater. Since smaller enclosed spaces help to boost the level of the lowest bass 

frequencies, smaller theaters can be overwhelmed by the strong low-bass output of 

the Fathom IWS subwoofer. This can create a “thick” or “bloated” character in the 

lower bass region. Turning down the “e.l.f. trim” knob cuts the extreme low bass 

level and alleviates this condition. Feel free to experiment and listen to a variety of 

demanding material until you find the best match for your room and your tastes.

Your Fathom IWS is now optimized for maximum bass performance at your 

listening seat.  Congratulations!  

IMPORTANT! IF YOU MOVE YOUR PRIMARY LISTENING SEAT IN THE 

FUTURE, YOU WILL NEED TO RUN A.R.O. AGAIN.  ANY PARTICULAR 

CALIBRATION IS UNIQUE TO THAT PARTICULAR SUBWOOFER POSITION 

AND LISTENING SEAT POSITION COMBINATION.  SIMPLY FOLLOW THE 

STEPS ABOVE TO CREATE A NEW CALIBRATION CURVE.

IMPORTANT

IMPORTANT! WRITE DOWN ALL SETTINGS PERFORMED IN STEPS 2-4 FOR 

FUTURE REFERENCE.

IMPORTANT

Summary of Contents for Fathom IWS-SYS-1

Page 1: ...IWS SYS 1 IWS SYS 2 Owner s Manual...

Page 2: ...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 or amplifier 10 Power sources The subwoofer should o...

Page 3: ...d 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 perfor...

Page 4: ...arch into high performance loudspeaker and amplifier technologies JL Audio s long excursion subwoofer driver designs are widely considered as reference standards for linear behavior and high output We...

Page 5: ...peaker 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 co...

Page 6: ...s 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 f...

Page 7: ...n bass performance BEST SEATING POSITIONS Most accurate bass performance COMPROMISED SEATING POSITIONS More intense but less accurate bass performance WORST SEAT CENTERLINE OF ROOM APPROX 1 3 OF TOTAL...

Page 8: ...rack 3 The Fathom IWS amplifier also includes table top hardware Special front panel end covers that replace the rack ears and rubber feet are included with the IWS amp To use the amp on a table top s...

Page 9: ...ong the front wall near the front left and right speakers or at the center points of opposing walls as shown at right Experimentation with listener placement is recommended to achieve the best results...

Page 10: ...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 Exper...

Page 11: ...om IWS subwoofer A R O page 12 13 Power page 12 Input Mode page 13 Level Mode page 13 Master Level page 14 Lights page 14 LP Filter page 14 LP freq Hz page 14 e l f trim dB page 15 phase deg page 15 P...

Page 12: ...as desired If this happens remove the Y cable adaptor or look for the noise source in the upstream components Automatic Room Optimization A R O A powerful feature of the JL Audio Fathom IWS subwoofers...

Page 13: ...start Should this happen simply wait for the Demo sequence to end and try again Calibrate Button During the ARO test sequence the Calibrate button s green LED will blink quickly to alert the user to t...

Page 14: ...utterworth alignment 24 dB sets the roll off slope of the low pass filter to a 24 dB per octave slope Linkwitz Riley alignment The 24 dB setting more aggressively attenuates high frequencies above the...

Page 15: ...g 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...

Page 16: ...and right input jacks are provided for systems without a dedicated mono subwoofer connection This typically applies to two channel audio equipment Appropriate balanced cables are available from your J...

Page 17: ...receivers and preamplifier processors Separate left and right RCA type input jacks are provided for systems without a dedicated mono subwoofer connection This typically applies to two channel audio eq...

Page 18: ...ction any further If your installation incorporates two or more Fathom IWS amplifiers you will designate one Fathom IWS as the Master and all others in the system as Slave via the Master Slave switch...

Page 19: ...ut to Slave signal carries any signal processing selected on the Master Fathom IWS including the Master Level setting and A R O processing to further Fathom IWSs operating in Slave mode From Fathom IW...

Page 20: ...ced RCA type connector Balanced connections provide superior noise rejection and ensure proper grounding between components If your receiver or processor has balanced outputs we highly recommend that...

Page 21: ...uts we highly recommend that you use them to connect to the Fathom IWS designated as the master In the connection diagram at right balanced connections are shown as solid lines unbalanced connections...

Page 22: ...sover and are comfortable running your main speakers full range you can split your preamplifier s output signals using appropriate Y connectors in place of the active crossover shown in the diagram Tw...

Page 23: ...connection types are available for connecting the Fathom IWSs to your two channel audio system balanced XLR or 1 4 inch TRS connector and unbalanced RCA type connector Balanced connections provide su...

Page 24: ...o the primary listening seat including the subwoofer s distance Use a tape measure to determine these distances time coherence is important If multiple Fathom IWSs are being used average their distanc...

Page 25: ...he unit connected directly to your receiver or preamp processor is indicating Master on its Input Mode lights and that all other units are indicating Slave on their Input Mode lights If not you will n...

Page 26: ...bwoofer at your primary listening seat and apply a powerful equalizer to tame the peaks caused by room modes resulting in smoother more accurate bass performance If you are using multiple Fathom IWSs...

Page 27: ...wait for the Demo sequence to end and try again You can perform a new calibration by following the normal procedure outlined above 2 Level Setting Using familiar music or movie material with deep bass...

Page 28: ...oost at 28 Hertz and is particularly useful when using a Fathom IWS or two in a small to medium sized home theater Since smaller enclosed spaces help to boost the level of the lowest bass frequencies...

Page 29: ...ted on the inputs When powered down only housekeeping circuits remain on which draw negligible amounts of power from the wall less than 10 watts Should I unplug my subwoofer during a thunderstorm or e...

Page 30: ...manual especially if any upstream components cables etc have recently changed 2 Turn off the Fathom IWS disconnect all its input and output signal cables turn the Fathom IWS back on If the noise disa...

Page 31: ...ot allow limitations on implied warranties therefore these exclusions may not apply to you This warranty gives you specific legal rights and you may also have other rights which vary from state to sta...

Page 32: ...of 10k Ohms Balanced Inputs Stereo or Mono two female XLR jacks Input Impedance of 10k Ohms Output To Slave Balanced one male XLR jack Input Modes Master or Slave Level Modes Reference fixed gain or...

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