6
7. Protection
Limiters
Peak Limiter
The Subwoofer, Midbass and Tweeter channels have individual Peak Limiters designed to protect each
driver from high amplitude, short duration audio input signal spikes that might cause damage due to
over excursion of the voice coil. These limiters are implemented digitally within the DSP in such a man-
ner that they have zero effect on the audio signal below their thresholds. The front LED indicator light
will flash RED when a Peak Limiter on any of the driver channels is triggered. The duration of such
events is only a fraction of a second. Therefore, the LED flash may appear pink or orange as the eye
naturally blends the normally aqua-blue color of the LED with the red.
RMS Limiter
The Subwoofer, Midbass and Tweeter channels have individual RMS Limiters designed to protect each
driver from long duration, high amplitude audio input signals that might cause thermal damage due to
the voice coil. These limiters are implemented digitally within the DSP in such a manner that they have
zero effect on the audio signal below their thresholds. The front LED indicator light will flash RED when
a RMS Limiter on any of the driver channels is triggered.
Caution:
Signals large enough to trigger any of the limiters can generate very high sound pressure levels
that may result in permanent hearing damage.
Over Current
In the event of a large audio input signal that might damage the amplifiers or power supply due to cur-
rent overload, the power supply is designed to enter into Over Current protect mode. This state typi-
cally results from a large, broadband input signal burst that flat lines the limiters on all four channels
simultaneously. While the fault persists the amplifier power rails shut down, the speaker goes quiet,
and the front panel LED turns red. Once the audio input signal is turned down the speaker should re-
boot within a few seconds. If the speaker fails to reboot or the LED light goes out completely, discon-
nect the audio input cable and power cycle the speaker. Verify the signal level is attenuated before
reconnecting audio input cable.
Caution:
Signals that cause Over Current protection to trigger can generate very high sound pressure
levels that may result in permanent hearing damage.
8. Positioning
The acoustic center of the MicroMain27 Gen2 is located at the center of the tweeter. The MM27 Gen2 is
designed to work equally well as a nearfield or mid-field monitor. The minimum recommended listening
distance is 1 meter (39.4”). While speaker positioning can sometimes be dependent on the nature of the room, a
good starting point is to create an equilateral triangle between the two speakers and the listening position. The
speakers should be angled inward approximately 30 degrees so the tweeter axes aim towards the listener’s ears,
crossing a few inches behind the head.
When the speakers are standing vertically, the “Barefoot” text on the front faceplates of both speakers should be
on top. When the speakers are turned on their sides to the horizontal orientation, the “Barefoot” text on the
front faceplates should be towards the outside. This places the ’bottom’ midbass drivers towards the center of
the stereo field.
Summary of Contents for MicroMain 27 Gen2
Page 1: ...Owner s Manual ...
Page 14: ...13 13 Drawing ...
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Page 18: ...Barefoot Sound LLC http barefootsound com 2013 ...