Connectors; Operating Instructions; Setup; Audio Signal - HK Audio SL 218 A Manuel

5. Connectors

Connector ports are mounted out of harm's way on
a recessed panel on the back of the SL 218 A.
Mains In
The SL 218 A features a locking Powercon mains
socket. Use the factory-included mains cord to
connect to it. (Also refer to the section of this
manual entitled Operating Instructions).
Signal In
Connect the SL 218 A to the audio signal source
using this electronically balanced female XLR input.
If you have additional devices to which you would
like to send this same signal, you can do so by
connecting them to the male XLR output labeled
Through. The XLR sockets' pin assignments are
as follows:
pin (1) = ground,
pin (2) = signal (+),
pin (3) = signal (-).

6 Operating Instructions

6.1 Setup

Ensure the cooling vents on the back of the SL 218 A
remain unobstructed and there is sufficient ventilation.
Do not set the enclosure against a wall, curtain, or
drape. If you choose to install the SL 218 A in an
enclosed space (such as a stage prop, below a stage
front or in a wall recess) you must provide sufficient
ventilation to prevent heat accumulation.
When stacking two or more SL 218 As, ensure that
the rails at the bottom of the upper SL 218 A fit
snuggly into the grooves atop the lower SL 218 A.
6.2 Connecting to Mains Power
Only use a cable with a grounded (earthed) three-pin
plug when connecting to mains power. The mains
outlet itself must also be equipped with a ground
contact. Never use damaged cords, plugs, or sockets.
Before connecting the SL 218 A to mains power, ensure
that the local mains voltage and line frequency
comply with the SL 218 A's specifications.
Important note!
When connecting several SL 218 As to one mains
outlet, make certain that the outlet as well as all
connected cables and distributors are designed to
handle the aggregate power. Heeding proper power
ratings is essential for safe and reliable operation.

6.3 Audio Signal

The incoming audio signal level must lie within the
SL 218 A's input sensitivity range. The input voltage
level at which the SL 218 yields its full rated output
is +4 dBu (standard level). The integrated controller's
input circuit can handle voltage levels up to +22 dBu.
Note that at this level, the SL 218 A's peak limiters
activate and limit power output to levels that the
power amps and loudspeakers can safely handle.
Note
A limiter serves protective and preventive purposes.
When a limiter triggers, it inevitably adds a form of
distortion that degrades the signal's quality to at least
some degree. For this reason, you should always set
the audio signal to a level within the SL 218 A's
standard range, so that the limiters should only
trigger briefly in response to signal peaks rather
than activate continuously.
Also ensure that the entire audio signal chain prece-
ding the SL 218 A is free of distortion. If a saturated
signal is routed into the SL 218 A, you will hear
distortion even if you have dialed in the correct
input gain level. Always connect all cables before
powering up the SL 218 A.
To protect against inductive and capacitive loading
(stray pick-up), only use balanced audio cables. Ensure
that the pin assignments of the XLR connectors
match specifications. If they do not, the low-frequency
signal may be cancelled altogether.
For some applications, it is recommended that you
route the audio signal to the SL 218 A via the mixing
console's AUX Send or matrix output. This way, you
can send only those audio signals to the SL 218 A
that actually require low-end reinforcement, for
example, the kick drum. Audio signals such as vocals
that do not require low-end reinforcement are then
not patched to the SL 218 A, thereby reducing the
risk of low-frequency rumble.
Regarding other connection possibilities, if you
operate the SL 218 A in parallel with the analog or
digital controllers that are driving the PA system,
you may in some cases be able to get by with a simple
Y-adapter. Note that if you connect many signal
inputs in parallel, you may be compelled to employ
line amplifiers, depending on the overall input
impedance and the mixer's maximum output power.
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