Beyerdynamic is a German company founded in 1934 by Eugen Beyer as an electrical engineering factory. The company is still owned by the Beyer family. On the consumer side Beyerdynamic makes headphones and microphones. On the industrial/commercial side Beyerdynamic makes headsets for pilots, wireless conferencing systems, and many other small electronics.
Notable products include the Beyerdynamic T 1 headphones, the Beyerdynamic A 1 headphone amp, and the Beyerdynamic CK 930 microphone.
The T 1, for example, is a over-the-ear headphone that is rated at 5 Hz to 50 kHz and is capable of 102 dB.