L8400P (serv.man11) - JBL Audio User Guide / Operation Manual. Page 6

Move the Master Power switch
 to the “On” position to use
the L8400P/230 subwoofer.

If you will be away from home
for an extended period of time,
or if the subwoofer will not be

used, switch the Master Power
switch 

 to the “Off” position.

The subwoofer Level Control
 adjusts the volume of the
subwoofer relative to the rest
of the system. Proper level

adjustment depends on several
variables such as room size,
subwoofer placement, type of
main speakers and position.

Adjust the subwoofer level so
that the volume of the bass
information is pleasing 
to you.

The Crossover Frequency Con-
trol 

 determines the highest

frequency at which the sub-
woofer reproduces sounds. If
your main speakers can com-
fortably reproduce some low-
frequency sounds, set this
control to a lower frequency
setting, between 50Hz and
100Hz. This will concentrate
the subwoofer’s efforts on 
the ultradeep bass sounds
required by today’s films and
music. If you are using smaller
bookshelf speakers that do not
extend to the lower bass fre-
quencies, set the low-pass
crossover control to a higher
setting, between 120Hz and
150Hz. This control is not used
when the LFE switch 

 is in

the “LFE” position.