Appendix; Wiring Requirements - JBL LSR6328P/PAK Owner's Manual

Appendix A

Wiring Requirements

For optimum performance, some attention to wiring details now can reduce system degradation later. The cabling recommendations
given below follow standard wiring practice for differential inputs.
Balanced Sources: The best way to run your system is balanced, where both "HOT" (+) and "COLD" (-) signals are supplied from the
source along with a GROUND/SHIELD. These are typically carried on 2 conductor shielded cables with XLR connectors on both ends.
Alternatively, connectors with Tip, Ring and Sleeve (T/R/S) jacks can be used. Whenever possible, the cable shield should not be con-
nected to any signal pin, but left to perform a cable shielding function only. Note: Under no circumstances should the safety ground wire
be removed from the AC power connector.
When using balanced sources with the LSR6328P, either the XLR or T/R/S input of the Neutrik Combi connector can be used, since the
circuit is common to both. The difference between the two is that the T/R/S input is generally set for a nominal -10 dBV input and the
XLR input is generally set for +4 dBu.
For balanced signals, the HOT (+) signal from your source should be connected to the tip of the T/R/S connector or Pin 2 of the XLR
input as shown in Diagram A. The "COLD" (-) signal should be connected to Pin 3 of the XLR or the "Ring" of the T/R/S connector. To
avoid ground loops, connect the SHIELD at the source end but not at the LSR input.
Diagram A
Unbalanced Sources: When using unbalanced sources, there are more possibilities to introduce ground loops into a system. The
LSR6328P and LSR6312SP offer several ways to help alleviate potential problems with unbalanced equipment.
While there are only HOT and GROUND/SHIELD connections from
unbalanced sources, it is recommended that high quality twisted
pair cable be used. Diagram B shows an unbalanced source
connected to the balanced XLR input of the LSR monitor using
twisted pair cable. Note that the shield is connected to the
GROUND/SHIELD connector at the LSR input, but not at the
source. This reduces the likelihood of introducing a ground loop
into the system.
When using unbalanced signals with an LSR6328P, it is recom-
mended to use a 1/4" Tip/Ring/Sleeve connections. Diagram C shows when using the 1/4" Tip/Ring/Sleeve connection, the GROUND
should be tied to the source -- not the sleeve -- of the LSR input for optimum performance.
Diagram C
16
Balanced Source
Pin 2
+
(Tip)
Pin 3
-
(Ring)
Pin 1
(Sleeve)
Diagram B
Unbalanced Source
Tip
+
Sleeve
LSR Input
Pin 2
+
(Tip)
Pin 3
-
(Ring)
Pin 1
(Sleeve)
Unbalanced Source
Tip
+
Sleeve
LSR28P T/R/S Input
Tip
+
Ring
-
Sleeve
LSR XLR Input
Pin 2
+
Pin 3
-
Pin 1