sub sonic filter down to 10 hz?

if we only hear down to about 20hz, is this the part of the bass that you feel? and would that require special subs meant to play that?

every crossover has a slope that is measured in decibels per octave, an octave is a doubling of frequency, so if you double 10 you get 20. and because a crossover isnt just a straight cut off frequency but rather a slope, if you would have an 12db per octave slope and it is set to 10hz then it would also effect the 20hz band just a little. most sub woofers play from about 20-30hz. the sub sonic filter can be used to protect the subs in extreme cases but id say usually it is used when whatever box you have your subs in wont allow you to hear notes below a certain frequency so people turn the sub sonic close to that frequency to keep the subs from playing any notes that the box wont let you hear anyway.

You "feel" virtually all subsonic frequencies if they are powerful enough.
And then there's the brown note(s) etc which you also feel, but usually not knowingly until it's too late!

i would also like to add that the subsonic crossover is a highpass crossover. it allows frequencies that are higher than the set frequency. the same way a high pass filter protects your normal speakers, a subsonic filter can protect and enhance your sub woofers by allowing them to only play frequencies that are they are designed to play.

makes sense. thanks guys!   brown notes, nice.