Driving Forces in Multichannel Audio

Transcription

1 Technologies Lecture 2: 1857: First Monophonic recordings - Edouard-Leon Scott of France built the phonautograph 1878: Thomas Edison invents the mechanical cylinder phonograph 1

2 Multiple Phonographs used in a recording session : Clement Ader implements the worlds first multichannel transmission: Concert Hall 2

3 1882: Clement Ader implements the worlds first multichannel transmission: La Lumiere Electrique The Paris Grand Opera House in listening with both ears at the two telephones, the sound takes a special character of relief and localization which a single receiver cannot produce! 1892: AT&T Telephone Concerts (attempt no.1) Newton Massachusetts to New York City - From Scientific American : it has been found desirable to have a separate transmitter [microphone] for each instrument... If one transmitter is arranged to transmit music emanating from 50 instruments it must be so adjusted that the average result will be fair. At the receiving station, when it is desired to fill halls of considerable size, as many as six loud-speaking receivers are used... These are distributed about the hall, being usually attached to the chandeliers. - The whole thing was wired with transmitting microphones in series! MONOPHONIC sound!! 1933: AT&T Telephone Concerts (attempt no.2) Academy of Music (Philadelphia) to Constitution Hall (Washington) Harvey Fletcher (Bell Labs) implements 3 channel pickup and transmission system. Audience Philadelphia Washington 3

4 1933: Leopold Stokowski was the (Remote) conductor His assistant, Alexander Smallens conducted the orchestra (Philadelphia) Stokowski conducted the levels (Washington) Audience Philadelphia Washington Stereo comes of age 1931: Around the same time as Fletcher s experiments in spaced microphone techniques, Alan Blumlein develops two channel coincident stereo techniques. Patent: Improvements in, and relating to, sound recording and sound reproduction systems Vid Cinema leads the way 1940: Disney develop Fantasound at their Hyperion studios for the film Fantasia. Stokowski was again involved in the creation of pieces for the soundtrack. The first constant power panpot was developed for moving sources around an audience. Audience 4

5 Stereo comes of age 1931: Alan Blumlein develops two channel stereo. Patent: Improvements in, and relating to, sound recording and sound reproduction systems Bear in mind this application was written a couple of years after the first 'talking picture'! 1958: The first domestic stereo technology only became practical 20 years later. First stereo LPs appeared in homes in Delayed by the war, conversion of LPs to 78rpm to 33rpm. 1961: FCC (Federal Communications Commission ) authorized stereo broadcasting. Quadraphonic Cacophony 1960 s: Peter Schreiber develops the matrix CBS (Benjamin Bauer) developed the idea and created SQ (stereo quad). Soon after there were numerous conflicting formats: - QS matrix from the Sansui Corporation, - QMX from University of Illinois professor Duane Cooper (supported by Nippon Columbia), - and another format called Ambisonics from Michael Gerzon in the United Kingdom. The introduction of magnetic tape further complicated things! The quadraphonic era ended because the record industry could not make enough money from it. Enter Dolby 1970 s: Dolby modify the matrix for Cinema - They extract the centre and surround effects channels from the two left and right channels. - They used optical track technology for mono compatibility 5

6 Enter Dolby 1980 s: Dolby Laboratories develop the format for the home video, calling it ProLogic. 1992: Dolby digital debuts in cinemas. 6 discrete digital channels for 5.1 surround sound. DTS 5.1 and SDDS also become formats adopted by movie theatres. Stereo Optical Further layout developments 2000 s: DTS-HD 7.1 (Including with Height layouts) Further layout developments 2000 s: Tom Holmann Labs

7 2000 s: NHK 22.2 Further layout developments 1910 s: Edison s Cylinders Vs. Emile Berliner s disks Edison, a stickler for sound quality, refused to produce the disks until the late teens, when Berliner's patent expired 1920 s: 78 rpm gramophone record formats: - Lateral versus Edison s vertical "hill-anddale groove cutting. - Resulted in Edison bowing out of the record industry s: Vinyl record formats: - Columbia Records' 12-inch (30 cm) Long Play (LP) 33⅓ rpm microgroove record versus RCA Victor's 7-inch (17.5 cm) / 45 rpm Extended Play (EP) during the years Record players were redesigned to use either type 7

8 1960 s: Portable audio tape formats: 8-track and four-track cartridges versus Compact Cassette. - The 8-track eventually lost due to technical limitations, including variable audio quality and lack of fine control 1970 s: Quadraphonic encoding methods: CD-4, SQ, QSMatrix - The expense (and speaker placement troubles) of quadraphonic, coupled with the competing formats and lack of record industry support added to the demise of quadraphonics s: Vinyl Record Vs Compact Cassette With the advent of walkmans, cassettes quickly outsold vinyl and became the dominant format Vs. Compact Cassette vs. CD - Although 1980s-era portable CD players challenged cassettes, early players had problems with skipping due to vibrations & shock, which was unsatisfactory to the consumer. 8

9 1990 s: - Minidisc Vs Digital Compact Cassette Consumers very cautious and neither format ever achieved widespread popularity. Vs. - Digital audio discs: DVD-Audio versus SACD. DVD-Audio: Based on Pulse Code Modulation (PCM) SACD: Direct Stream Digital (DSD) And the winner was. - High-definition optical disc formats: Blu-ray Disc versus HD DVD. Sony PS3: Blu Ray XBOX 360: DVD with optional external HD-DVD player. 9

10 Conclusions - The format wars teach us that driving forces behind Multichannel audio Technologies are dictated by both public demand and manufacturer costs. - New formats are likely to be less physical based and more software based - High Definition audio is currently not as big a concern for consumers as HD video but this will hopefully change in the near future. - Manufacturers must consider competing formats in their technology for successful resolution to such wars. 10