Audio Technica AT-MX341b SmartMixer, Installation And Operation Manual

Page: 7 / 12

Mode 2 … All Priority Pre-select switches Down
In this mode, only one mic at a time can be “on.” The lockout bus shuts down all other mics until
the first speaker pauses. As soon as the controlling microphone goes silent, the lockout bus goes
inactive and any other mic can come on. This switching takes place without any
syllable-grabbing delay, or pops or clicks. (This mode is known as “First-come-first-served”
or “Filibuster.”)
This mode is very useful when the gain setting of the overall sound system must be close to the
threshold of feedback, and additional microphones coming on could throw the system into feed-
back. The SmartMixer will not allow multiple microphones to be on at the same time in this mode.
The switching is so fast and silent that the meeting can still be completely interactive.
Mode 3 … One Priority Pre-select switch Up
The selected priority microphone can come on at any time and can mute any other mic that is on
(popularly called “The Chairperson” mode).
(Note that there may be special circumstances where two or three mics could be set to priority,
so those speakers could talk whenever desired, but still mute one or two non-priority mics.)
If multiple SmartMixers are used with AT8325/1.0 Link Cables, Priority Pre-select switches on all
channels in use will have the control effects described above.
The selected priority microphone(s) will mute only those non-priority microphones within the
same unit.
Preamplifier Gain
The SmartMixer has a substantial gain range, allowing it to accept a wide variety of micro-
phones. However, if in some instances higher-output microphones are used for close talking, it
may be necessary to reduce the preamplifier gain. This can be done by changing switch settings
inside the unit. With the unit unplugged, remove the two screws on each side of the unit and
remove the top cover. Locate the internal switches designated on the circuit board by “S103,”
“S203,” “S303” and “S403” (Figs. 3 and 4, page 8). Changing the settings of these internal
switches will cause a gain reduction of 10 dB for channels 1, 2, 3 and 4 respectively.
The preamplifier gain may be reduced further, allowing the SmartMixer to accept line-level
sources. Changing the settings of the internal switches designated by “S101,” “S102,” “S103”
and “S104” will cause an input reduction of 50 dB for channels 1, 2, 3 and 4 respectively. Note
that the appropriate internal switches can be used in combination for a total sensitivity reduction
of up to 60 dB for each channel.
Output Gain
The SmartMixer’s output is factory set at line level. Should mic-level output be desired, simply
unplug the unit, remove the top cover and locate the switch on the circuit board marked “S501”
(Figs. 3 and 4, page 8). Changing the setting of this switch will cause a 50 dB reduction in output.
Phantom Power
Each of the SmartMixer’s inputs su12V DC phantom power. Should it be required to dis-
able the phantom power, simply unplug the unit, remove the top cover and locate the switches
designated on the circuit board by “S102,” “S202,” “S302” and “S402” (Figs. 3 and 4, page 8).
Changing the settings of these switches will disable phantom power on channels 1, 2, 3 and 4,
respectively. Note that, although they do not require phantom power for operation, most bal-
anced-output dynamic microphones can be used without disabling the SmartMixer’s phantom
power.
7