Dynaudio AIR 15 Reference Manual page 65

Phase parameter (subwoofer parameter)
Range: 0 to 180º
The integration of the AIR BASE subwoofer with the AIR
monitors requires on location tuning. Apart from level
calibration and choosing a Bass management cross-
over frequency, the issue of phase alignment remains.
For this purpose, AIR BASE subwoofer have a 0° to
180° phase adjustment (in 5 degree steps) and a Polar-
ity parameter. The optimum setting of these will depend
on several factors:
Room acoustics
►
Placement of monitors and listening position
►
Set crossover frequency
►
AIR Monitor type (6 or 15)
►
Phase settings are automatically saved and linked to
the currently selected crossover frequency.
Phase settings are Global settings and are not saved
with individual presets.
Dynaudio Professional AIR reference manual – 2014-09-28
Phase – initial setting
During calibration of the AIR BASE's DSP software, we
have come up with default settings that we found op-
timal in our listening room. If you are placing the AIR
BASE subwoofer at the same distance from your lis-
tening position as the AIR Monitors, the default phase
settings can be used as initial guidelines for setting the
phase. If the distances are significantly different, these
values are not likely to be optimal.
Phase adjustment
Play a low-frequency sweep signal that sweeps
►
over the crossover frequency that you have cho-
sen. Tracks 31 to 42 from the Dynaudio Profes-
sional AIR test tone sets may be used. Repeat as
necessary.
Between each sweep, change the Polarity setting.
►
Note the difference.
Ideally (i.e., with the right level calibration and phase
setting), the sound should cancel out and virtually dis-
appear at or near the crossover frequency when the
Polarity parameter is set to "180°".
Tune the Phase parameter to get the largest possi-
ble difference between the two Polarity settings. Then
leave it in the position where no cancellation occurs.
Iteration
You may need to iterate quite a bit, maybe readjust the
level calibration a bit as well. You may even want to
reconsider your initial choice of crossover frequency
and/or monitor placement and start the process over
again. Be patient – the time spent getting this right is
well spent!
Checking and optimizing monitor placement
62