JBL LSR6300 owner manual Appendix a, Wiring Requirements

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

Balanced Source

+	Pin 2
	(Tip)
-	Pin 3
	(Ring)
	Pin 1
	(Sleeve)

LSR Input

Pin 2	+
(Tip)
(Ring)Pin 3	-
Pin 1
(Sleeve)

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.

Diagram B

Unbalanced Source

+ Tip

Sleeve

LSR XLR Input

Pin 2	+
Pin 3	-
Pin 1

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.

Unbalanced Source		LSR28P T/R/S Input
Diagram C
+	Tip	Tip	+
		Ring	-
	Sleeve	Sleeve

16