Front-Panel Volume Control
The volume control on the amplifier’s front panel can be used to blend the subwoofer output with that of the main speakers in the
system. The best approach is to audition the unit with various audio selections before choosing a setting. Start with the volume
control at “Off” (fully counterclockwise), and then raise it gradually. (This will prevent woofer damage that might occur is if the
system is run too “hot.”) Very little movement of the knob is needed.
CAUTION:
If a popping sound (clipping) is heard through the subwoofer, it is being overdriven. To prevent speaker damage,
reduce the volume at the amplifier.
Rear-Panel Controls
The following controls allow you to blend the output from the M3 subwoofer with the sound from the main speakers:
Power Switch
The power switch on the amplifier’s rear panel activates/deactivates all amplifier circuitry and, in the “Off” position, overrides Auto
Sense mode.
Low-Frequency (Low-Pass) Crossover
Use this control to adjust the upper frequency limit of the M3 system. The purpose is to control the overlap of the M3’s upper
frequencies and the lowest frequencies of the main speakers. However, this control will not affect the fixed 75HZ setting when the
built-in high-frequency (high-pass) crossover is used by connecting speakers to the speaker output connectors on the M3 ampli-
fier.
Bass Boost Control
This control lets you adjust the audio response centered around 40Hz, to optimize subwoofer performance in the environment
into which it is installed. A boost of up to 3dB at 40Hz is provided.
Polarity Control
Depending upon placement of the subwoofer and the main speakers, and the environment in which they are placed, the Polarity,
or phase, of the M3 needs to be optimized. While the system is playing, set the switch to “180º” and then back to “0º” in order to de-
termine which setting feels louder, tighter and more controlled. The significance of this control will vary according to subwoofer,
main speaker placement, and room acoustics.
Volume-Limit Control
Use this control to adjust the maximum volume setting of the M3 system. With the volume-limit control and front-mounted
volume control turned down all the way (counterclockwise), turn on the subwoofer and play audio through the system. Turn the
system up to the highest level that can be heard comfortably without distortion. Next, turn up the subwoofer volume on the front
panel of the M3 amplifier all the way. (There should still be no bass output at this point.) Then, gradually turn up the volume-limit
control until the subwoofer plays as loudly as possible without distortion. Finally, return the levels to normal. Now it’s possible for
anyone to turn up the subwoofer all the way without risking system damage.
4
Diagram 2
Front-Panel of M3 Amplifier
Active Blue LED Volume Control
