Community VERIS Series - Operation and Installation Manual - Page 17
Typical Input Panel for Autoformer Equipped Models
PIN DESIGNATIONS
The pin designation is as follows:
•
‘C’ or ‘common’
connects to the ‘C’ or Ground connection on the amplifier
(typically a black binding post).
•
One of the taps connects to the positive output of the amplifier (typically a red
binding post).
USING POWER TAPS
A VERIS loudspeaker equipped with an optional autoformer has four taps. These are set at
25W, 50W, 100W and 200W on the two larger models, and 12.5W, 25W, 50W and 100W on
the two smaller models.
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 3
dB louder than the first loudspeaker. A third loudspeaker might be tapped at 200 watts,
which would make it 3 dB louder than the second loudspeaker, and 6 dB 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 levels.
Typically, every time you double the distance from a sound source, the level drops 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, be aware that 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.
That said, the use of pink or white noise to excite the system, and a sound level meter to
take nearfield measurements, will help you precisely balance the relative level of each
loudspeaker in a sound system. Just make sure to take your readings at an identical
distance from each of the loudspeakers in the system, otherwise the results will be skewed.