Manual

4
The SP2120 Speaker Protector is designed for standard
19" rack mounting and occupies 1U of rack space. Where
possible, avoid mounting the unit directly above power
amplifiers or power supplies that radiate significant amounts
of heat.
If the unit is to be used in a mobile situation, it is strongly
recommended that the rear of the unit is supported in the
carrying rack to avoid bending the front panel rack mounting
‘ears’. Use fibre or plastic washers to prevent the front panel
becoming marked by the mounting bolts. Always connect
the mains earth to the unit.
Drawmer have gone to great lengths to make the Speaker
Protector tamper-proof by incorporating the locking
mechanism on the front, however, if the rear of the unit,
along with the power amplifier, were reconnected, by an
engineer/dj trying to gain more level, then the protection
system would effectively be bypassed. For this reason it
is imperative that both the SP2120 and the power amp be
locked in a rack, where access to the rear is very difficult.
Fig. 1 shows the ideal connection setup, providing the
greatest protection for your system. Note the position of
the SP2120 along the audio chain - it should be connected
directly before the amplifier that is supplying the speakers,
(or before the active speakers), with the amplifier volume
set to maximum. If the SP2120 were to be connected earlier
in the chain, prior to the pre-amp/mixer for example, then
it would be possible to add gain, sending noise levels higher
than required.
The SP2120 can be used in a configuration where a stereo
output is distributed around several speakers. Fig.3 shows
a setup where the signal is distributed into six pairs using
a Drawmer DA6, whilst still providing speaker protection
for all twelve speakers. Again, note the position of the
SP2120’s along the audio chain - they should all be
connected directly before the amplifier that is supplying
the speakers (or active speakers), with the amplifier volume
set to maximum.
INSTALLATION
AUDIO CONNECTIONS
The inputs and outputs are electronically balanced XLRs where pin 1 is screen, pin 2 hot, pin 3 cold and the XLR shell
is connected to chassis. The operating level is nominally +4dBu. Balanced use is recommended.
• Interference:
If the unit is to be used where it maybe exposed to
high levels of disturbance such as found close to a TV
or radio transmitter, we advise that the unit is oper-
ated in a balanced configuration. The screens of the
signal cables should be connected to the chassis con-
nection on the XLR connector as opposed to connect-
ing to pin1. The SP2120 conforms to the EMC stand-
ards.
• Ground Loops:
If ground loop problems are encountered, never dis-
connect the mains earth, but instead, try disconnect-
ing the signal screen on one end of each of the cables
connecting the outputs of the SP2120 to the patchbay.
If such measures are necessary, balanced operation
is recommended.
fig.1 XLR WIRING