Lanzar OPTIXA6B - Manual (Page 9)

1) SETTING THE SUBWOOFER CROSSOVER POINT, PHASE,& SUBSONIC FILTER
Set the desired CROSSOVER FREQUENCY for the subwoofer output using the LOW PASS
FREQUENCY dial. You may select from 40Hz up to 400Hz as your crossover point.
Select the PHASE of the subwoofer using the PHASE switch,0 degrees in phase or 180
degrees out of phase.The normal default setting is 0 degreed in phase.
SUBSONIC FILTER with a variable Full/30Hz/50Hz subsonic filter. This filter avoids the
reproduction of inaudible low frequencies on the amplifier which could damage the subwoofer
because they can generate over excursion of the subwoofer cone.You would want to set the
frequency point where you want the filter not to produce frequencies below that
point.Generally,human ears cannot hear low freqencies below 20Hz.
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