in the high end of the frequency spectrum. Due to their bidirectional pick-up pattern, ribbon microphones may be used in pairs to produce the Blumlein Pair recording array. In addition to the standard bidirectional pick-up pattern, ribbon microphones can also be configured to have cardioid, hypercardioid, and variable pattern. As many mixers are equipped with phantom power in order to enable the use of condenser microphones, care should be taken when using condenser and ribbon microphones at the same time. If the ribbon microphone is improperly wired, which is not unheard of with older microphones, this capability can damage some ribbon elements; however, improvements in designs and materials have made those concerns largely inconsequential in modern ribbon microphones. History In the early 1920s, Drs. Walter H. Schottky and Erwin Gerlach co-invented the first ribbon microphone. By turning the ribbon circuit in the opposite direction, they also invented the first ribbon loudspeaker. A few years later, Dr. Harry F. Olson of RCA started developing ribbon microphones using field coils and permanent magnets. The RCA Photophone Type PB-31 was commercially manufactured in 1931, greatly impacting the audio recording and broadcasting industries. Condenser microphones at the time could not compare to its frequency response. Radio City Music Hall employed PB-31s in 1932. The following year, the 44A came on the scene. Its tone and pattern control helped reduce reverberation. Many RCA ribbon models are still in use and valued by audio engineers. The BBC-Marconi Type A was an iconic ribbon microphone produced by the BBC and Marconi between 1934 and 1959. Also of note is the ST&C Coles 4038 (or PGS – pressure gradient single), designed by the BBC in 1954 and still used for some applications to this day. Its historical uses varied from talks to symphony concerts, and it is regarded as a delicate, fine traditional microphone. The German Beyerdynamic M 160 was introduced in 1957, fitted with a smaller microphone element with two 15 mm ribbons combined to create a highly directional pickup pattern. The microphone proved to be popular in recording studios. Around 2002, relatively inexpensive ($80 – $200) ribbon microphones manufactured in China and inspired by the RCA-44 and older Soviet Oktava ribbon microphones became available. UK based Stewart Taverner and his company XAudia developed "The Beeb", modifying vintage Reslo ribbon microphones for better tone, performance and increased output. In 2007, microphones employing ribbon elements made of strong