Phase And Polarity - Samson Auro D1800 Operation Manual

Phase and Polarity

A speaker reproduces sound by converting electrical signal into physical vibration.
This physical vibration, in turn, pushes air to create sound waves. When setting up your
speaker system, the goal is to have all speakers moving in phase, with the in and out
movement of the speakers synchronized.
0° 90° 180° 270° 360°
This produces an even sound across all
audible frequencies. If the subwoofer is
Phase SW = NORMAL
out of phase with the full range front of
house speakers, you may notice decreased
Time
bass response, or even bass frequency
cancellation where satellite and subwoofer
frequency responses overlap. Many times
this phenomenon is very subtle, but it can
Phase SW = INVERT
produce the effect of "holes" in the music,
and diminished bass frequencies.
Ideally, your Auro D1800 subwoofer should be positioned on the same plane as your
satellite speakers. In reality, we know this is difficult, as there are restrictions when
setting up a PA system due to space limitations, speaker stand configuration, or even
speaker cabinet shape. To compensate for these obstacles, the Auro D1800 features
a Phase switch, which allows you to reverse the polarity of the subwoofer relative to
the source signal. This enables you to put the D1800 in phase with the rest of your PA
system, or 180° out of phase.
To determine if the audio produced by your D1800 is in phase with the rest of your PA
system, play an audio track containing a lot of bass frequencies through your speaker
system. Stand at a good listening distance, where you can clearly hear the audio from
the subwoofer(s) and mains speaker(s), and listen until you believe you have a good
gauge of the level of bass frequencies. Press the Phase switch on the D1800 to reverse
the phase by 180°, and move back to your original listening position (if possible, have
someone else press the Phase switch so that you can stand in the exact same loca-
tion). Compare the overall level of the bass frequencies between the two settings. The
correct setting will result in more bass frequencies. If the situation allows, you can fine-
tune the phase of your D1800 to your satellite speakers by moving the relative position
of the subwoofer closer or further away from the listening position.
9
Owner's Manual Auro D1800