RobertR
Senior HTF Member
- Joined
- Dec 19, 1998
- Messages
- 10,675
I know most people seem to use the term "subsonic", but it more properly should be called "infrasonic", similar to the term "infrared". Both refer to to frequencies that are below the range of human senses. "Subsonic" means "below the speed of sound", just as "sublight" would mean "below the speed of light".