16. INFRASONIC FILTER.
Loudspeakers with "vented" cabinets (Le. bassreflex,
ported, auxiliary bass radiator, and drone-cone
designs) are especially susceptible to being overdriven
by inaudible signals below 20 Hz, especially
from a turntable. If your speakers are of this type,
switch the Infrasonic Filter ON, especially when playing
LP records.
If you have sealed-cabinet (acoustic suspension)
loudspeakers, or if you listen mainly to Compact Discs
or tapes, the infrasonic filter may be switched OFF.
NOTE: A second infrasonic filter is included in the
BASS EQ circuit and is automatically engaged when
the bass equalization is used. It is not affected by the
Infrasonic Filter switch.