Owner's manual

OPERATING INSTRUCTIONS
Before describing the setup procedure for the system, each function available in the DC1 will be explained.
AUTO SKEW DISPLAY
This function displays the instantaneous mix of Pre and Post VCA signals for each channel. The longer the display
bar for any given channel, the greater is the proportion of Pre-VCA signal to Post-VCA signal. Except in the Auto
Gain Skew "Off" mode, the current active microphone will display the longest bar. Note that this display is the only
DC1 function which is active in both the Operate and New Setting modes.
AUTO GAIN SKEW
The Auto Gain Skew function provides the capability to minimize the interruption of the active microphone by non-
speech signals such as coughs, paper rattling, etc. Auto Gain Skew dynamically changes the relative proportion of
Pre-VCA to Post-VCA channel level signal. In this way, channels which are active for a significant amount of time
will tend to dominate inactive microphones. Auto Gain Skew also helps eliminate "bleed-over" of a talker into
adjacent closely spaced microphones.
The Auto Gain Skew may be set to one of three speeds, Fast, Medium, or Slow in addition to Off. The Fast setting
provides the best operation when the interchange between microphones is lively (e.g. a talk show or panel
discussion), at the expense of some noise rejection. The Slow setting provides the maximum noise rejection, and
is appropriate for situations where there is less interchange between microphones (e.g. a church or lecture). The
Medium setting is a compromise setting. When Auto Gain Skew is Off, all channel signal levels consist of a mix
the Pre-VCA and Post-VCA signals, each attenuated 6dB.
Three alternate settings are useful in situations with high background noise: Fast , Med , and Slow (note the
asterisks). These three settings will release the Auto Gain Skew if the DC1 determines that there is only noise
present on all channels and no valid speech signal.
MAX ATTENUATION
The Max Attenuation adjustment allows the maximum attenuation of each channel to be optimized for both the total
number of microphones in use and the specific acoustic situation. The range of the Max Attenuation adjustment is
6dB to 20dB in 1dB steps.
LEVEL MATCH
The Level Match function allows the apparent channel signal level to be increased or decreased by up to 30dB, in
1dB increments. The actual audio signal path gain is unaffected by changes in the Level Match value. The Level
Match function is used to minimize variations in sensitivity (and as a result, access to the system) which might
result from the use of microphones with different sensitivities in the system. In addition, the Level Match function
may be used to give a soft talker access to the system equivalent to louder talkers.
CHANNEL MODE
There are two operational modes for each channel in the DC1, Direct and Auto. In Direct mode, the channel is on
regardless of activity on that channel or on any other channel. In Auto mode, the channel operates as an
automatic mixer.
PHANTOM POWER
48 volt phantom power is available on a per channel basis. If the microphone requires phantom power, be sure to
turn phantom power on for that channel.
INPUT TYPE
The microphone preamp has two gain settings for high and low level microphone sources. These settings are used
to match the output levels of all types of microphones. The "High" setting is most appropriate for high output
electret microphones. The "Low" setting is better matched to dynamic microphones, which have a lower output
voltage. Note that these are only suggestions, and the actual setting depends on other factors as well, like the
talkers’ distance to the microphone, the talkers average level, etc.
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