Earthworks C&C30 User Manual - page 6
Installation and Positioning of the ChoirMics™
Notice in Figure 12 what happens if the rear of the Earthworks cardioid microphone
is not positioned toward the orchestra or band.
ChoirMic™ Design Philosophy
The majority of conventional hanging choir microphones suffer from several similar
design flaws. Some have the microphone electronics installed in the ceiling with
unbalanced microphone cable going to the microphone. Such designs are often
susceptible to radio frequency interference (RFI) or picking up hum from nearby
electrical lines. Another common flaw is the use of small, lightweight microphone
housings that do not have enough weight to pull the cable straight when suspended
from the ceiling. These lightweight microphone housings sometimes move due to
the air blowing on them from the air conditioning system. Another problem is the
use of cables that will move or rotate due to temperature or humidity changes. These
microphones may be perfectly positioned, then a few days later may be pointed a dif-
ferent direction as the cable has rotated due to temperature or humidity changes.
The Earthworks ChoirMic is larger in size than most conventional choir micro-
phones, however, all of the electronics are housed inside the microphone body and
the output is low impedance and balanced. This greatly reduces the likelihood of
RFI problems. In addition, high quality Canare™ Star Quad™ microphone cable is
used which provides greater insurance against RFI. This premium microphone cable
is also guaranteed not to rotate or move due to temperature or humidity changes.
The heavy microphone body also provides enough weight to pull the microphone
cable straight down for a good cosmetic appearance.
Installers will love the mini-gooseneck on the ChoirMic, as it allows easy positioning
of the microphone head. Many conventional choir microphones require a
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Figure 12. Improper Positioning of an Earthworks Cardioid Microphone
with an Orchestra or Band behind the Microphone
Incorrect
- microphone
head at an angle to floor
causes poor isolation from
the orchestra or band
Figure 4. An 80-voice choir miked with 6 conventional microphones at 6 feet
How Earthworks Near-perfect Polar Response Can Benefit You
There are several ways near-perfect polar response can benefit you.
1. Use of fewer microphones
2. Ability to place microphones closer to the sound source for more gain
before feedback.
3. No spotlighting or highlighting
4. More rejection of sounds from the rear of the microphone
5. Singers on the sides of the microphone enjoy the same quality as those in
front of the microphone.
Fewer Microphones Required
Referring to Figure 2b, notice how narrow the pick-up pattern is on a conventional
cardioid microphone. In comparison, notice how much wider the pickup pattern is
on the Earthworks cardioid microphone (Figure 3b). Keep in mind that the shaded
areas in these figures indicate the area where you can obtain the full frequency re-
sponse of the microphone without a significant loss of high frequencies.
Conventional microphones (Figure 2b) only provide a narrow window (or area) in
which they can pick up sounds with full frequency response. Figure 4 below, shows
an 80-voice choir miked with conventional microphones. It takes 6 conventional
microphones, placed 6 feet in front of the choir, to adequately cover the choir with
the full frequency response of the microphones.
In contrast, the near-perfect polar response of Earthworks cardioid microphones
provide a wider pickup pattern (or area) where you can obtain the full frequency
response of the microphones. Figure 5 on the following page, is the same 80-voice
choir is covered using only 3 Earthworks cardioid microphones.
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