User manual

Page 6 of 39
HALO system User Manual
V2.2 August 2010
3.0 - Connections, Processor and Amplifier Selection
Connecting your loudspeakers
HALO enclosures are bi-amplified and use Neutrik Speakon
TM
NL4 connectors - as such
they require 4-core cable to function correctly. Standard pin connections are LF/MF on
pins 1+/1- and HF on pins 2+/2-.
HALO-S subwoofers are wired pins 1+/1- with pins 2+/2- connected as a link-through.
Cable Selection
All cables add to the system impedance, and as such careful selection is required
depending on your amplifier setup and overall system impedance. Recommended
maximum cable lengths are given below:
Conductor Area Maximum Recommended Cable Length
4 ohms 8 ohms 16 ohms
1.0mm
2
11m 22m 44m
1.5mm
2
17m 34m 68m
2.0mm
2
22m 44m 88m
2.5mm
2
29m 58m 116m
4.0mm
2
44m 88m 176m
6.0mm
2
66m 132m 264m
IMPORTANT NOTE REGARDING SYSTEM IMPEDANCE
The HALO HF drive unit drops to 4 ohms across a reasonable portion of its operating
band. This can cause problems with some amplifiers when connecting the high frequency
sections of more than two HALO enclosures in parallel on an amplifier channel. However,
with the cable lengths involved in most line array usage scenarios, there is sufficient
impedance in the cable alone to bring the impedance up to a suitable level to prevent
amplifier problems. We would recommend when connecting 3 or more HALO high
frequency sections to a given amplifier channel, ensure cable runs of at least twenty
metres between the amplifier and the loudspeaker.
Amplifier Powers
We recommend the following power inputs for HALO enclosures:
HALO LF/MF (8 ohm impedance) 500W RMS, 1000W Program
HALO HF 375W RMS, 750W Program
HALO-S (4 ohm impedance) 1000W RMS, 2000W Program