178.738UK User Manual
Rear Panel
27.
Cooling fan
28.
Power on/off switch
29.
IEC mains inlet and fuse holder
30.
Right channel SPK + jack outputs
31.
Left channel SPK + jack outputs
Setting Up
Connect speakers via the outputs on the rear panel (30, 31) using good quality speaker leads with
6.3mm jack or SPK connectors and twin core cable, recommended no smaller than 2 x 0.5mm² CSA.
When connecting speakers to the outputs, ensure that the combined load on either channel is no
lower than 4 Ohms (4Ω). To make sure of this, check the manufacturer’s information.
If connecting more than one speaker, observe the following calculation method.
Most PA and sound reinforcement speakers are 8Ω, so we consider that
1/8
+
1/8
=
1/4
Therefore, when connecting 2 x 8Ω speakers to a channel on the PHX series PA head, the resulting
total load is
4Ω
.
When 2 speakers are connected to a single output, each speaker will receive half of the rated output
of that channel.
With the power switch (28) in the Off position, connect the IEC inlet (29) to the mains using the
power lead provided.
Connect a microphone via one of the balanced XLR inputs (9) or a line input to an unbalanced jack
connector (8) for each channel to be used.
