JBL LSR4312SP, Owner'S Manual

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X
If you want to enable bass management when using the digital inputs, be sure to set the fi fth rear-panel DIP
switch to the “Bass Management” (RIGHT) position. The LSR4312SP can reproduce signal from a maximum of
two channels when using the digital inputs. If you need it to reproduce signal from all surround sound channels in
a bass managed setup, use the analog inputs instead, or use an external bass management processor, connected
to the digital input.
X
If you want to disable bass management (that is, have the LSR4312SP reproduce the LFE channel only) when
using the digital inputs, be sure to set the fi fth rear-panel DIP switch to the “LFE” (LEFT) position and connect the
correct digital pair (typically the one carrying Center/LFE signal) to the AES/EBU or S/PDIF input, then use the
third and fourth DIP switches to select the channel that is carrying the LFE signal (typically the right, “B” channel).
For best results when using digital inputs, always use high-quality cable designed for use with digital
equipment. We recommend the use of 110 ohm cabling (not longer than 100 meters, or 330 feet) for AES/
EBU connections and 75 ohm cabling (not longer than 10 meters, or 33 feet) for S/PDIF connections.
Typical Audio Connections
The illustrations on the following pages show audio interconnections for integrating an LSR4312SP
subwoofer into stereo and surround LSR4300 systems. For information on integrating two subwoofers,
see Appendix B on page 36 in this manual.
Note: In 5.1 and 6.1 surround sound applications (that is, wherever there is a dedicated “.1” LFE channel),
bass management is optional. Connections to the LSR4312SP analog bass management inputs and
outputs (Left, Right, Center, L Surround, R Surround) are therefore `optional; you only need to make these
connections if you plan on using bass management. See Appendix A on page 34 in this manual for more
information.
Protection Circuitry in the LSR4312SP
Driving a power amplifi er beyond its ability to produce clean power produces distortion that can damage
the transducer. The LSR4312SP Subwoofer incorporates a peak limiter to reduce short-term peak signal
levels that can cause amplifi er “clipping” and subsequent distortion. The limiter is set to reduce signals
that exceed the level above which the amplifi er clips.
In the unlikely event a long-term sustained low frequency input signal causes the system to overheat, a
thermal protection system in the LSR4312SP will activate and attenuate the output level of the subwoofer.
Normal operation will resume following a reduction of the input signal.
Reference - Digital Connections
System Protection