EDIT:Originally Posted by Toofastgs
In an effort to appease others...
Low Pass Filter: A filter which attenuates frequencies which are above it's stated "cut off" frequency.
Examples using a system:
Woofer
HPF -- 25hz @ 24db (incorrectly referred to as subsonic filter, also known as infrasonic filter)
LPF -- 125hz @ 12db
Mids
HPF -- 100hz @ 12db
LPF -- 2.4khz @ 12db<------denotes fall off/attenuation
Tweet
HPF -- 2.6khz @ 12db
In the example above, I use the LPF to let my sub play 20hz to 125hz. I have the option of using an Infrasonic filter but I don't...I threw that in as part of the example so you'd understand it's purpose. At the other end of the spectrum my tweeter plays from 20khz to 2.6khz.
Typically when you use an HPF and LPF on the same driver it's referred to as a band pass. Not to be confused with bandpass enclosures. Same idea though since most bandpass enclosures require an infrasonic filter.
Matt will correct me if I made any mistakes
