JL Audio Fathom f112 Owner's Manual page 20

Input Mode Switches:
Two switches are located on the rear panel to control unbalanced signal
grounding and master/slave operation.
"Grounded / Isolated" Switch
Th e "Grounded / Isolated" Input Mode switch aff ects only the unbalanced
RCA inputs and is designed to facilitate a quiet, hum-free connection to your
audio or home theater system. Th is feature is included to deal with the signal
grounding issues oft en encountered in home theater systems when several
components from diff erent manufacturers are interconnected.
Th e 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-frequency hum through your Fathom, fl ip this switch to the
"Grounded" position and evaluate the diff erence 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
Th e Fathoms are designed to easily accommodate the implementation
of multiple subwoofers in your home theater system through a master/slave
connection chain. Th is 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.
Th e 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 amplifi er 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-defi nable signal 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 and level-matching controls, activating
the "Slave" mode will prevent anyone from aff ecting system parameters with
the manual controls on the Fathom.
Page 20
IMPORTANT
| Fathom f112 & f113