PLEASE HAVE A LOOK AT THIS GERMAN HORN FROM COMPANY STARTED IN 1929. DOES ANNY ONE HAVE AN IDEA.
http://www.cornu.de/history_isophon.html
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PLEASE HAVE A LOOK AT THIS GERMAN HORN FROM COMPANY STARTED IN 1929. DOES ANNY ONE HAVE AN IDEA.
http://www.cornu.de/history_isophon.html
HiQuote:
Originally Posted by CONVERGENCE
I know this shown speakers very well......they were from the years of 1977 to 1986 and placed in the market in this HiFI and DIY times.
I had some of this horns. They sounded good but had never the power capability like the JBLs in this time (cooked some several times.....maybe also in cause of not exactly tuned crossovers).
Yes...they started in 1929, like most of the basic speaker manufacturers with this "new" system in this times.
HP
Their claims of "firsts" are not correct. They claim to have invented crossover networks and two-way speakers in 1935. However, W.E.'s three-way Wide Range System, two-way Fletcher System, and MGM's two-way Shearer Horn all pre-date their system. They claim to have invented the coaxial speaker in 1949 but W.E., Altec, Stephens and Tannoy all had coaxials on the market before then. In W.E.'s case it was 15 years earlier.
I`ve had this drivers in the late 70`s. They were low cost horns with a spl around 100 dB but sound was good. Horn of the highf driver ia made from die cast(?). The lenses are also made from metal (still have them here), but will not fit the 1 inch JBL horns:biting: .
Eckhard
you are absolutely right Don,Quote:
Originally Posted by Don McRitchie
my (not completed ) database shows this:
HP
PS. perhaps we can fill the white spots:bouncy:
Hi HP
There are a few corrections I would offer to your database. I know the source of many of them - Altec's published timeline. I have Altec's working file that contained the correspondence used to develop that timeline in 1985 in advance of Altec's 50th anniversary. By that time, virtually everyone involved with the original Altec Corporation had left the company. Those that were left tried to piece together their history from various fragments and it ended up with a final document that was riddled with errors. At any rate, here are the discrepancies that I spotted.
1935 James B. Lansing Los Angeles first duplex speaker developments with field coils
Lansing Manufacturing never made a duplex speaker. Jim would not develop such a speaker until after joining Altec Lansing in 1941.
1936 Douglas Shearer MGM Shearer Horn with JBL Speaker
The "who" on this system should rightfully be John Hilliard. He was the project manager and responsible for defining the system. Shearer just paid the bills as head of MGM. The date for development was 1935 and not 1936. However, full production did not occur until 1936.
1936 Douglas Shearer MGM first flat wire voice coil in Tweeter with phase plug
The W.E. 555 of 1927 used both a flat wire coil and a rudimentary phase plug. The now universally used concentric slot phase plug dates from 1933 and the W.E. 594 compression driver which also used flat wire. The only unique feature about the compression driver used in the original Shearer Horn was that it employed the first radial phase plug design (similar to the later Altec Tangerine). This was developed by John Blackburn at Lansing Manufacturing as a means of circumventing W.E.’s patent for the 594. This patent was later invalidated by a court challenge which proved prior art, and the production Shearer Horns went back to a concentric slot phase plug design.
1942 James B. Lansing Altec first permanent magnet in an Altec speaker 604, developed by James B Lansing
Altec had permanent magnet speakers from the day they bought Lansing Manufacturing in 1941 since Lansing Manufacturing had Alnico II permanent magnet versions of their field coil drivers for some time. The 604 dates from 1944 and what was distinctive about it was that it was the first loudspeaker to use Alnico V for its permanent magnet. This material was much more powerful than Alnico II and for the first time allowed PM speakers with magnetic motors that matched or exceeded their field coil predecessors.
1943 Altec first 12" Duplex speaker from Altec, Model 601
The Model 601 was Jim Lansing’s and Altec’s first duplex loudspeaker. However, it was a 15" driver and not a 12" driver using field coils for the motor. Only 100 were ever built. The following year, Jim Lansing converted the magnet structure to Alnico V and increased the bass driver voice coil from 2" to 3" to result in the 604. Otherwise, the 601 and 604 were identical.
1947 James B. Lansing Lansing Sound Incoporated first speaker ever with 4" voice coil as D130
The D130 was the first 15" driver with a 4" voice coil, but not the first speaker with such a coil. The W.E. 756 and others from 1940 used 4" coils.
1947 Altec first Voice of Theater speaker
Development of the first VOTT likely occurred in 1944. The first papers describing the system and widespread demonstrations occurred in 1945.
1953 James B. Lansing Lansing Sound Incoporated Robert Hartsfield developed the "Hartsfield" speaker as a copy of a Klipschorn
1954 James B. Lansing Lansing Sound Incoporated first Alnico 2" driver, based on Western Electric 594 but with 4" voice coil as 375
1954 James B. Lansing Lansing Sound Incoporated acoustic lens developed by B.N. Locanthi were introduced
These are all interrelated. B.N. Locanthi's acoustic lens was first, dating from 1950. It should be noted that this was based on research at ATT labs so that he could not be called the inventor of the accoustic lens. The first model was the small "potato masher" used with the D175. The 375 dates from 1952 and was developed for JBL’s first large theatre system The Hartsfield dates from 1954 and incorporates both the 375 and an acoustic lens.
1958 James B. Lansing Lansing Sound Incoporated the "Paragon" was introduced
The date of introduction was actually 1957.
Thanks Don,Quote:
Originally Posted by Don McRitchie
that's what I need :)
the above shown pdf was made by me two years ago with the timeline you talked about. In the meantime I saw also in our forum historic library some differencies to my timeline.........
BTW: while searching the web for further infos , I found this forum :)
HP
For Isophon look at www.lup-berlin.de. Only for germans:D .
Eckhard