Community WET II - Operation and Installation Manual - Page 16
70V AND 100V OPERATION
Using Power Taps
A WET II loudspeaker equipped with an optional autoformer has four selectable power taps. These are set at
12.5W, 25W, 50W and 100W on the
W2-218,
and at 25W, 50W, 100W and 200W on the
W2-228
, the
W2-2W8
,
and the
W2-312
for 70V systems (note: for 100V systems the taps equal twice the numeric value stated
above; i.e. a 25W tap becomes a 50W tap, and so on). Note that the autoformer has a maximum output
capability of 200W regardless of the primary voltage.
By choosing one of the four taps, you can govern how much amplifier power is available for each
loudspeaker. For example, if the 50W tap is selected, that particular loudspeaker will draw 50 watts of
power when a 70V amplifier is run at its maximum level. A second loudspeaker might be connected to the
same amplifier, but tapped at 100W (100 watts). In such case, the second loudspeaker will draw 100 watts
from the same amplifier, making it 3dB louder than the first loudspeaker. A third loudspeaker might be
tapped at 200 watts, which would make it 3dB louder than the second loudspeaker, and 6dB louder than the
first.
By using the various taps, one can balance the relative sound levels in a system. A loudspeaker that is closer
to audience members will need to be tapped at a lower wattage than one that is farther away, in order to
produce similar output levels (of course the amplifier must be capable of delivering output power that is at
least equal to the sum of the taps).
As a guideline, every time you double the distance from a sound source, the level typically will drop by 6 dB,
which is equivalent to one-fourth of the power. Although this is an acoustical law, and is true in a free space
environment such as outdoors, the effect of room acoustics can radically change the actual results. Even
outdoors, it is normally not possible to validate this acoustical law using a sound level meter, due to the
ground plane effect.
