Specifications

The high-pass filter on Apogee APL-Series subwoofers (and on Apogee out-

board loudspeaker processors) provides a 24 dB/octave roll-off with a cor-

ner frequency of 100 Hz.The switchable Low-Cut filter on the APL-220, -500,

and -800 provides a 12 dB/octave 100 Hz high-pass filter. With the 12

dB/octave high-pass filter in place, the APL-220, -500, and -800 become capa-

ble of approximately 6 dB greater overall output than when used in the flat

(full-range) mode. When fed from a 24 dB/octave high-pass filter, they

become capable of even greater output before the onset of low-frequency

protective limiting. Experiment with the Low-Cut switch and with the High-

pass subwoofer output to achieve the best sounding results for your partic-

ular application.

(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.

Figure 5

An APL-500 full-range speaker placed directly over an APL-10 subwoofer