Palmer CAB 212 G12A OB Manuel D'utilisation page 22

NOTE
Some speakers have a lighter cone and will also move if the air pressure
changes within the cabinet. For example, if you do the above battery test
on a 412 cabinet with Celestions Vintage 30 and you just give the spea-
kers a short impulse then it may appear that the speakers are moving in
different directions. In this case, make the battery connection and hold
it – the speakers should all move in the same direction and stay there as
long as you keep the battery connected.
CHECKING THE IMPEDANCE
You can check the impedance of your cabinet using a simple Ohmmeter or
Multimeter. Connect a speaker cable to the cabinet and hold the test
prods of the multimeter to the other end. Set the Multimeter to Ohms (re-
sistance) and note the reading.
NOTE
Keep in mind, the reading of the multimeter does not show the impedance
(which is frequency dependant), it is just showing the resistance. So the
readout will not be exact but close enough to verify that the speakers
are wired correctly. For example an 8 Ohm speaker can have a readout of
roundabout 6.5 or 7 Ohms.
Be sure to test the cabinet with an amp before you take it on tour or
to a gig. Start at lower volumes and then slowly increase the level. If
there is no sound then stop playing, turn the amp off or to standby and
double check all the connections.
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