The Wharfedale MACH 9) Some competing loudspeakers sold at the time were the Bose 901 Series IV and V, Bose 201 Series I, Bose Series 601 Series II, JBL Delta, Cerwin Vega D series, JBL Radiance, JBL Sigma, and Acoustic Research AR-58B. The Wharfedale MACH The Wharfedale MACH series of loudspeakers consists of the MACH 3, 5, 7, and 9. This is an informational page devoted to owners and users of these loudspeakers and those interested in history and construction of electronic sound reproduction. These loudspeakers were manufactured at Rank Hi-Fi, Wharfedale Works in West Yorkshire by Wharfedale Loudspeakers in England (UK). They
Mach number Generally, NASA defines "high" hypersonic as any Mach number from 10 to 25, and re-entry speeds as anything greater than Mach 25. Aircraft operating in this regime include the Space Shuttle and various space planes in development. Flight can be roughly classified in six categories: For comparison: the required speed for low Earth orbit is approximately 7.5 km/s = Mach 25.4 in air at high altitudes. At transonic speeds, the flow field around the object includes both sub- and supersonic parts. The transonic period begins when first zones of M > 1 flow appear around the object. In case of