6.
Phasing
The Magnepan Pink Noise CD Test Disk included with your DWM can be used to determine if the DWM is in
ACOUSTICAL phase with your limited bandwidth Magneplanar. The test CD has a 9 db peak at 80-100 Hz that
draws attention to the frequencies which will be depressed in an out-of-phase condition. Place the DWM next to your
limited bandwidth Magneplanar and change the phase. (It is much easier to detect an out-of-phase condition when
the "small" speaker is physically next to the woofer.) Since the DWM is a dipole woofer, the easiest way to
determine if the DWM is in-phase is by simply turning the woofer around (180 degrees). The speakers are in-
phase when the peak is the loudest.
If you are uncertain if the acoustical phase is correct, a technique which can help is by leaning over and positioning
your head between the Magneplanar Woofer and the "small" Magneplanar as shown in Fig. 2 below. The left and
right ears are equi-distance to the respective speakers. High frequencies will appear to be up and low frequencies
will appear to be down. Midbass frequencies, if in phase, will appear to be in the middle (and louder).
Depending upon the location of the DWM with respect to the limited bandwidth Magneplanar, the DWM might be 90
degrees out of phase with the "small" Magneplanar and changing the phase does not make a noticeable difference
in the loudness of the pink noise peak. It may be necessary to move the DWM with respect to the Magneplanar to
achieve a better acoustical in-phase condition.
Fig. 2
