(3) Speaker Placement and Polarity when the APL-220, -500, and
-800 are used with Subwoofers
The optimum polarity for a subwoofer used with the APL-220, -500, and -800
is a function of its placement in relation to the full-range speaker that it is
used with. That is the phase
relationship
of the two systems, although
absolute
phase
also plays a role in the equation.
If the subwoofer is directly under or over the APL-220, -500, or -800, in near-
ly all cases the polarity of the subwoofer should be normal, that is, the same
as the APL-220, -500, and -800. See Figure 5.
NOTE: A positive signal applied to pin 2 of the XLR input connector will
result in a positive wavefront appearing at the front of an Apogee Subwoofer
if the Phase Reverse Switch is set in the normal position. This is also true for
the APL-220, -500, and -800 (i.e., they produce a positive wavefront when
excited with a positive signal on pin 2 of its input). In other words, both sys-
tems are normally in-phase with each other.
25
Figure 5
An APL-500 full-range speaker placed directly over an APL-
1
0 subwoofer
