JBL D123A as full ranger??

[Mr. Widget]

[i]My guess, though, is that the D just stands for "driver". In Jim Lansing's 1948 catalog, he used the D designation for every driver, including the D175 compression driver and the D130A woofer that used a paper dustcap. [/B]

Ok, but what about the 150-4C and the 375... well they did come along later, but then so did the D123 and the D208...

I'll put my money on D for driver and the the Lansing lack of consistency. Ask Bo about JBL's polarity conventions.

[4313B]

"Ask Bo about JBL's polarity conventions."

The only errant driver I know of is the 123A-1 and that driver can be either. One thing is for sure, it's probably a good idea to run the battery test on any 123A's one comes across and intends to use.

[Steve Schell]

Mr. Widget, you are correct that the 375 and 150-4C came along later, and the use of the "D" was inconsistent from then on. The D208, however, was an original Jim Lansing design and was being produced by 1948 or so. Hal Cox has told me that Jim Lansing designed the D208 to compete with the Altec 400 Dia-cone eight inch driver. Hal says that there was a lot of "buzz" at the AES meetings about the 400 being a very good driver for its size.

Jim Lansing may have had a hand in designing and tooling up to produce the 400 before he left Altec. The 400, 600 and 603 Dia-cone models all appeared about the same time, late 1945 or early 1946- about the time Lansing left Altec. The very idea of using an aluminum dustcap to extend highs may have been Lansing's. The term "Dia-cone" refers to the combination of a diaphragm and cone being used together in one unit.

I have an early Dia-cone in my collection; 603 serial #15. It has a red, white and blue label. It is still mounted to its original black 15" square baffle board, and the initials "JBL" are written on it in pencil. I have compared them to other examples we have of Jim Lansing's initials, and they appear to be genuine.