Mach 9 or variation, may refer to:
Mach number for nine times the speed of sound Hypersonic speed of 9 times the speed of sound Wharfedale MACH 9, a loudspeaker Mach-IX (Marvel Comics), comic book superhero alter-ego of Marvel Comics character Abner Jenkins "Mach 9 (nine) is equivalent to 6905.42 miles per hour - Source Google Unit Converter
See also
Mach (disambiguation)