SOUND TRANSLATING DEVICE

[tomt]

so this-

http://www.stereo.co.jp/lis.files/ph...LTEC-3000H.jpg


started here?

http://www.google.com/patents?vid=US...PPA1936-IA1,M1

[GM]

Greets!

Don't believe so, I think it's a spin-off from their earliest microphone and telephone loudspeakers, but couldn't find the patent in a quick search. For sure it uses an early design microphone diaphragm.

GM

[Steve Schell]

Tomt, as I understand it the Altec 3000 series tweeter diaphragm design began life as a Western Electric dynamic microphone diaphragm. Altec Lansing received a shipment of tooling and spare parts from W.E. in 1949 or 1950 when W.E. removed itself from speaker and microphone manufacturing due to a consent decree with the U.S. Government. Altec assumed manufacture of a number of W.E. designs and sold many pieces back to W.E. as an OEM vendor. Someone at Altec must have looked at these diaphragms and thought that they would make good tweeters, which proved to be correct.

The patent you cited is actually for a different device, the incredible bass compression driver that was used in the Fletcher Horn System. This two way system was developed for the Auditory Perspective experiments conducted by Bell Labs in 1933. This driver used a 20" (!) aluminum diaphragm fitted with an 8" edgewound aluminum voice coil, immersed in a 20 kilogauss flux field provided by the massive field coil motor. Now that's the way to build a bass driver!

The bass horn used with this driver can be studied in patent #1,970,926. The revolutionary high frequency section of this system can be studied in patents #2,037,187 (compression driver) and #1,992,268 (multicellular horn).

The Audio Engineering Society has published the original booklet from Bell Labs titled "Symposium on Auditory Perspective" on the web in PDF form. The entire booklet is fascinating; the chaper titled "Loudspeakers and Microphones" begins on page 17.

http://www.aes.org/aeshc/docs/bell.l...erspective.pdf

[tomt]

Originally posted by Steve Schell:
.

The patent you cited is actually for a different device, the incredible bass compression driver that was used in the Fletcher Horn System. This two way system was developed for the Auditory Perspective experiments conducted by Bell Labs in 1933. This driver used a 20" (!) aluminum diaphragm fitted with an 8" edgewound aluminum voice coil, immersed in a 20 kilogauss flux field provided by the massive field coil motor. Now that's the way to build a bass driver!

The bass horn used with this driver can be studied in patent #1,970,926. The revolutionary high frequency section of this system can be studied in patents #2,037,187 (compression driver) and #1,992,268 (multicellular horn).

[/URL]

<font size="2" face="Verdana, Helvetica, sans-serif">after reading the patent, i'm convinced,

the '3000' did come from, this design,

scaled down, of course-

and yes, this is fascinating,


http://www.aes.org/aeshc/docs/bell.l...erspective.pdf


who would have imagined, stereo,

before amplifiers?