1. BY: Mercedez Dixon

2. Audio crossover Audio crossovers are a class of Electric Filter used in audio applications. Crossovers split the audio signal into separate frequency bands that can be separately routed to loudspeakers optimized for those bands. http://en.wikipedia.org/wik i/Audio_crossover 1967

3. Diaphragm Performers sang and/or played into a large acoustic horn and the master recording was created by the direct transfer of acoustic energy from the diaphragm of the recording horn to the mastering Lathe, typically located in an adjoining room. a diaphragm is a transducer intended to faithfully inter- convert mechanical motion and sound http://en.wikipedia.org/wiki/Dia phragm_%28acoustics%29 1880

4. Microphone The Microphone was invented in the 1920 A microphone (colloquially called a mic or mike; both pronounced is an acoustic-to-electric transducer or sensor that converts sound into an electric signal Most microphones today use electromagnet Description (dynamic microphone), capacitance change (condenser microphone), piezoelectric generation, or light modulation to produce an electrical voltage signal from mechanical vibration. http://en.wikipedia.org/wiki/Micro phone 1827

5. amplification An amplifier is a device for increasing the power of a signal by use of an external energy source.power signal There are different kinds of amplifications. In an electronic amplifier, the input "signal" is usually a voltage or a current.electronic amplifier Other types exist; a fluidic amplifier increases the power of signals represented as flow of gas or liquid, for example.fluidic amplifier 1909

6. electric motor Edison introduces an electric motor-driven phonograph. 1888

7. wireless telegraphy system 1895 Marconi successfully experiments with his wireless telegraphy system in Italy, leading to the first transatlantic signals from Poldhu, Cornwall, UK to St. John's, Newfoundland in 1901. 1895

8. flat-disc 1887 Emile Berliner is granted a patent on a flat- disc gramophone, making the production of multiple copies practical. 1887

9. motion picture film. The Victor Talking Machine Company is founded by Emile Berliner and Eldridge Johnson. Experimental optical recordings are made on motion picture film. 1901

10. electronic signal amplifier. Lee DeForest invents the triode vacuum tube, the first electronic signal amplifier. 1906

11. Scully disk recording lathe 1917 The Scully disk recording lathe is introduced. E. C. Wente of Bell Telephone Laboratories publishes a paper in Physical Review describing a "uniformly sensitive instrument for the absolute measurement of sound intensity" -- the condenser microphone. 1917

12. commercial AM radio The first commercial AM radio broadcast is made by KDKA, Pittsburgh PA. 1921

13. 604 coaxial loudspeaker. Altec develops their Model 604 coaxial loudspeaker. 1943

14. The first Movie Ever Made Horse In Motion (1878) is the very first movie every made! http://voices.yahoo.com/th e-first-movie-ever-made- history-film-firsts- 679245.html (1878)

15. Rca RCA introduces the microgroove 45 rpm, large- hole, 7-inch record and record changer/adaptor. Ampex introduces its Model 300 professional studio recorder. Magnecord produces the first U.S.-made stereo tape recorder, employing half- track staggered-head assemblies. A novel amplifier design is described by McIntosh and Gow. 1949

16. EMT 1954 EMT (Germany) introduces the electromechanical reverberation plate. Sony produces the first pocket transistor radios. Ampex produces its Model 600 portable tape recorder. 1954

17. first commercial 1957 Westrex demonstrates the first commercial "45/45" stereo cutter head. 1957

18. first 2-track closed-loop 1961 3M introduces the first 2-track closed-loop capstan-drive recorder, the M-23. The FCC decides the FM stereo broadcast format. 1961

19. Audio mixers The first audio mixer was made in April 1993 http://in.answers.yahoo.co m/question/index?qid=201 00514120216AAS3kOf 1993

20. The End! That’s All Folks!