Community WET Series II, Руководство по эксплуатации и установке

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Community WET Series II - Operation and Installation Manual - Page 16
70V AND 100V OPERATION
Using Power Taps
A WET Series 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.