This is a quote that I found describing what it does!
"A built-in Ultra Low Bass Equalizing Circuit provides a 6 db boost at 30 cycles, for subwoofer-like response on speakers that can take it. And at the same time, it rolls off the bass at 12 db per octave, effectively removing all subsonic interference."
"A built-in Ultra Low Bass Equalizing Circuit provides a 6 db boost at 30 cycles, for subwoofer-like response on speakers that can take it. And at the same time, it rolls off the bass at 12 db per octave, effectively removing all subsonic interference."