L-Acoustics LA48A, Руководство пользователя

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L-ACOUSTICS LA48a Manual V1.0 27/01/2003 15
6.1.2 UNBALANCED INPUTS
To connect an unbalanced source, tie pin 3 (ring on TRS jack) to the shield of the connector. Note: if you
leave pin 3 disconnected, you will lose 6 dB.
A better method for using unbalanced sources is shown in Figure 8. This is similar to the connection for
balanced lines, but pin 3 is connected to the shield at the source. The hum and noise rejection for the
cable is equivalent to that for a balanced line. To minimize hum, use balanced inputs whenever possible.
Figure 8: Unbalanced Line Connection
Figure 9: Balanced Line with Unbalanced
Equipment
6.2 CONNECTING SPEAKERS
Speaker connections are made via the two Neutrik® NL4FC Speakon connectors. The Speakon
connector is designed for high power speaker connections and assures correct polarity, locks securely in
place and prevents from shock hazard.
The LA48a power amplifier Speakon connectors are wired in the following manner:
Channel A Channel B
Pin +1 Channel A+ Channel B+
Pin -1 Channel A- Channel B-
Pin +2 Channel B+
Pin -2 Channel B-
For normal two-channel operation, connect each speaker load across the Channel A, B output
terminals (positive and ground).
Since the Channel A Speakon is bi-wired, it is possible to access both channels on a single connector.
For bi-amped operation, be careful whether Channel A or B outputs are assigned to the LF or HF
component of your active loudspeaker system. As standard, L-ACOUSTICS active 2-way
loudspeakers are cabled as follows: LF +/- = 1+/1- (Ch A) ; HF +/- = 2+/2- (Ch B). Also pay
attention to speaker polarity: loudspeakers connected out of phase degrade sound quality and may be
damaged as a consequence.
Figure 10: Loudspeaker Connection Details
Channel A and B connected via two
separate Speakons Channel A and B connected via one
Speakon (for bi-amp applications)
Bridged mono connection via
Channel A output connector (pins
1+/2-) to loudspeaker (+/-)