View source for Milestone-Proposal:Improvements in and relating to Sound-transmission, Sound-recording and Sound-reproduction systems by Alan Dower Blumlein

{{Proposal
|docketid=2013-27
|more than 25 years=Yes
|within fields of interest=Yes
|benefit to humanity=Yes
|regional importance=Yes
|ou is paying=Yes
|ou is arranging dedication=Yes
|section is taking responsibility for plaque=Yes
|a11=Yes
|a3=1931 - 1934
|a1=Invention of Stereo Sound Reproduction, 1931
|plaque citation=Alan Dower Blumlein

For developing stereophonic sound, a two-channel audio system called “stereo” (patent filed 14 December 1931), which included a "shuffling" circuit to preserve directional sound effects, an orthogonal “Blumlein Pair” of velocity microphones, the recording of two orthogonal channels in a single record groove, the stereo disc-cutting head, and the hybrid transformer to mix directional signals. Blumlein brought his stereo recording equipment to Abbey Road Studios in 1934 and made recordings of the London Philharmonic Orchestra.

|a2b=UK&RI
|IEEE units paying={{IEEE Organizational Unit Paying
|Unit=IEEE UK&RI Section
|Senior officer name=Steve Nightingale
|Senior officer email=Steve.Nightingale@cobham.com
}}
|IEEE units arranging={{IEEE Organizational Unit Arranging
|Unit=IEEE UK&RI Section
|Senior officer name=Simon Blumlein
|Senior officer email=Simon.Blumlein@btinternet.com
}}
|IEEE sections monitoring={{IEEE Section Monitoring
|Section=IEEE UK&RI Section
|Section chair name=Simon Blumlein
|Section chair email=Simon.Blumlein@btinternet.com
}}
|Milestone proposers={{Milestone proposer
|Proposer name=Alan Blumlein
|Proposer email=Alan@AlanBlumlein.com
}}{{Milestone proposer
|Proposer name=Simon Blumlein
|Proposer email=Simon.Blumlein@btinternet.com
}}
|a2a=Abbey Road Studios, 3 Abbey Road, St. John's Wood, London NW8 9AY
|a7=Abbey Road Studios are working studios having been established in 1931. Abbey Road was the site of where on January 19th 1934, Alan Blumlein used his Stereo recording equipment to record Sir Thomas Beecham conducting the London Philharmonic Orchestra playing Mozart's Jupiter Symphony. 

There is one existing plaque on the front of Abbey Road which is dedicated to Sir Edward Elgar who officially opened the Abbey Road Studios on November 12th 1931
|a8=Yes -EMI research Building at Hayes Middlesex is Extant- the testing of Stereo cutting and recording equipment by Alan Blumlein was in an existing studio at Abbey Road
|mounting details=Outside of building on front face above or alongside the main entrance to the Abbey Road Studios.
|a9=The plaque will be firmly secured to the outside of the building. Visitors can view the plaque from Abbey Road and will not need access to the studios.
|a10=Abbey Road Studios
|permission letter=Abbey road JS.pdf
|a4=The historical significance of this work is that Alan Blumlein developed a single track, 2 channel recording system. Although he used the available methods of Hill and Dale & Lateral Cutting to achieve groves at 90 degrees to each other, he specified that 45/ 45 cutting system would have significant advantages. Within his patent, he went into great detail about the technology involved with the problems associated with sound reproduction and interpretation by the human brain.
|a6=Obstacles to be overcome included the fact that at the time of going to patent, shellac discs were used for commercial reproduction of recordings and better materials had to be developed. Shellac had limitations due to its use as a workable material and its poor reproductive qualities meaning that Shellac discs would not permit the playback of high quality sound. 

Electrical reproduction in the home was often opposed as to the amount of equipment required.

EMI had a focus on the development of television
|a5=Single grove two channel recording method 

Future development in the use of sound recording and reproduction for film was also covered in the patent.
|references=(1)Patent number 394,325 - Improvements in and relating to Sound-transmission, Sound recording and Sound-reproducing Systems http://www.doramusic.com/patents/394325.htm

(2)IEEE Global History Network Article - http://www.ieeeghn.org/wiki/index.php/Alan_Dower_Blumlein

(3)The Inventor of Stereo: The Life and Works of Alan Dower Blumlein
By Robert Charles Alexander. Focal Press, 1999. ISBN 0-240-51628-1 

(4)The Life and Times of A. D. Blumlein
Rusell Burns. IEE History of Technology Series, 2000 ISSN 0953-5683

(5) Alan Dower Blumlein Wikipedia - http://en.wikipedia.org/wiki/Alan_Blumlein

(6) EMI Archive Trust - Alan Blumlein and the Invention of Stereo http://www.emiarchivetrust.org/alan-blumlein-and-the-invention-of-stereo/

 (7) The New Stereo Sound Book Everest and Streicher TAB Books [prints patent 394,325 with comments ]
|supporting materials=EMI Archive Trust
Illustrations from the Stereo patent
|submitted=No
}}