Karl Rudolph Koenig (26 November 1832 – 2 October 1901) was a German businessman, instrument maker, and physicist, chiefly concerned with acoustic phenomena.

[1] Early on it was clear that Rudolph had a keen ear for music and a good sense toward art and literature.

Sounds in particular were a fascination of his, to the point that he spent a large amount of time and money doing research on acoustics.

[3] Although Koenig's lab and workshop were in a quiet place, this did not stop scientists and many other people such as Dayton C. Miller from coming to visit.

[2] One of Koenig's more interesting devices was a watch with the escapement consisting of a tuning fork that could calibrate the main frequencies of any sound.

[4] In the late 1800s Koenig found out that people were making cheap copies of his acoustical apparatus.

[6] In 1859, Koenig both published his first catalog, and inverted the phonograph which would play a crucial role for the graphical analysis of sound.

[7] Around 1860, along with Hermann von Helmholtz, Rudolph Koenig worked to devise an electronically controlled sound.

[9] In 1865,  Koenig published his second catalog, and was awarded a gold medal from the Societe d'Encouragement pOllr l'lndustrie ntuionale for the use of his instruments in working with the study of acoustics.

This led to Koenig having to travel to America in order to retrieve his leftover products and bring them back.

[citation needed] Following all of this he decided to start doing more of his own research, and also began to write many scientific articles while improving upon his instruments.

[10] After his death in 1901, some of Koenig's equipment was sent and is now maintained in Conservatoire des Arts et Métiers, Paris.

The Smithsonian Institution has since began a collection of Koenig's apparatus including some of his tuning forks.