Ericjcbrera, there are plenty for full range speakers available.
Nandric, Stereophile is fixated on 20-20K because that's the limit of the recording mediums available to us. It is felt (ha!) that frequencies below 20 Hz such as the pedal tones of some organ music is felt through one's body rather than heard through one's ears. I wonder if most of our listening rooms rattle might swamp these frequencies if they were indeed available.
Nandric, Stereophile is fixated on 20-20K because that's the limit of the recording mediums available to us. It is felt (ha!) that frequencies below 20 Hz such as the pedal tones of some organ music is felt through one's body rather than heard through one's ears. I wonder if most of our listening rooms rattle might swamp these frequencies if they were indeed available.