the control to a fairly low value at 40, 60, or even
100 Hz. If the main speakers are smaller or do not
have much bass output, set the control higher.
Experiment with the amount of “overlap” that you
will experience when all speakers are playing in the
same range. This can be helpful when integrating
the subwoofer with the rest of the system and with
the room.
6. Power Switch
This switch manually turns the unit on and off. When
switched to the on position, the unit will rst turn on
and be fully operational. After a period of 10-15
minutes without a signal the unit will go into “stand
by” mode.
7. Power LED
When the power switch is moved to the “on”
position, the LED will illuminate in green, and the
amp will be in “stand by” mode. If a low level signal
of about 3 millivolts or greater is applied to the
input, the light will change color to yellow to indicate
that the amplier is fully operational and receiving
typical music program. As input signal increases to
the onset of clipping the LED will turn red, which
indicates that the clip limiting circuitry is activated. If
an input signal is not detected for 10 to 15 minutes,
the amp will go back to “stand by” mode and the
LED will change back to green.
8. Phase
This two-position (NOR = 0° phase and REV = 180°
phase) switch helps to compensate for differences
in the acoustical and electrical characteristics
between the subwoofer and the main system
speakers. The relative locations of speakers in the
system can cause signicant disturbances in
speaker interaction due to time delay issues, or the
destructive phase interferences that can occur at
certain frequencies. The use of this switch in
conjunction with altering the location of the
subwoofer can have a dramatic effect on system
integration. The “NOR” setting would be considered
the normal or default setting, but be sure to
experiment during system set-up.
PARAMETRIC EQUALIZER
The amplier features a fully parametric equalizer to
help you to achieve the best possible subwoofer
performance. Professional sound engineers have for
many years considered the parametric EQ to be one
of the most accurate, versatile, and high delity
tools for audio enhancement. A greater degree
of control can be achieved when using the EQ’s
unique ability to vary the frequency to be affected,
the amount of boost or cut, and the width or
narrowness at the selected frequency.
9. EQ-Frequency
Establishes the specic frequency at which EQ boost
or cut may be applied between 18 Hz and 80 Hz.
10. EQ-Bandwidth
Determines how narrow or wide the EQ curve will be
within a range of 0.1 to 1.0. If for example a frequen-
cy of 60 Hz were selected along with a Q of 0.1, the
frequencies to either side of 60 Hz would be less
affected. This is a narrow bandwidth that could be
useful for “surgically” removing an offending peak
without disturbing adjacent frequencies. At the other
extreme, a Q of 1 would result in a much broader
effect which could be used for smooth overall bass
boost or cut, to balance the overall tone character of
the sub.
11. EQ-Level
Permits the application of up to 6 dB of boost or
14.5 dB of cut at the selected frequency and band-
width. Setting the control at the 0 position effectively
removes the EQ from the circuit path. It is good to
remember that high levels of boost reduce amplier
headroom; it is the same as turning up the low pass
gain control but only at the selected EQ frequencies.
It would be helpful to reduce or increase the low
pass gain control to balance the amount of cut or
boost applied by the EQ.
12. Output Lead for Subwoofer Driver:
This rear mounted output lead connects the amplier
to the subwoofer driver. The output lead is roughly
20" long and is color coded. The red wire uses an
insulated .250" quick disconnect and the black wire
uses an insulated .205" quick disconnect. These
connectors can be easily removed if your driver
requires another size or type of connector. Be sure to
observe proper polarity when connecting the
amplier to your subwoofer driver (red = positive,
black = negative).
NOTES ABOUT HUM
While this amplier has been designed to minimize
the possibility of hum in the subwoofer system, it is
still possible that a hum may occur in rare
circumstances. Its safety grounding can create a
path for small amounts of 60 Hz energy to travel
through the line-level audio system. While not
