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norwaydelta
04-10-2009, 06:40 AM
Hello
I live in central japan.
I bought pair 600B with 622B cabinet on the auction.
My question is ,"Who invent the metal center dome cap?"
It improve high freq.characteristic we know.
JBL D101 also equipped it.
J.B.Lansing did?
I do not know the history of Speaker well,
Please give infomation about it.
B.regards

Steve Schell
04-10-2009, 11:00 AM
Norwaydelta, you have posed an interesting question, one I have pondered myself.

Many years ago, long time JBL dealer and enthusiast Hal Cox received several artifacts from long time JBL company president and owner William Thomas. These had reportedly belonged to Jim Lansing, and had been removed from Lansing's work area in the JBL factory on Fletcher Drive after his death. Among these was a small 1930s field coil radio speaker that, unusually for its time, used a small aluminum center dome/dust cap. Thomas had speculated that perhaps this driver provided Lansing with the inspiration for his wide range drivers which used an aluminum center dome.

Altec Lansing introduced their line of "Dia-cone" wide range drivers prior to Jim Lansing's departure from the company in late 1946. These included the 8" model 400, 12" model 600 and 15" model 603. All used an aluminum diaphragm glued to the end of the voice coil former to extend the high frequency response. Although John Hilliard wrote an article on the 603 which was published in 1947, I consider it most likely that these drivers were designed primarily by Lansing. As soon as he left Altec, Jim Lansing began producing his D-101 15" wide range driver, working in the barn of his avocado farm in San Marcos, CA. Soon after came the familiar D-208, D-131 and D-130 drivers. All of these new Lansing Sound (later JBL) drivers utilized the aluminum center dome.

norwaydelta
04-12-2009, 12:50 AM
Dear Steve

I am very pleased with your reply.


I consider it most likely that these drivers were designed primarily by Lansing.

At a glance I saw the photo of 600B on Yahoo auction,I was certain that Jim Lansing had desigined 600B.But NO confidence yet.
Many thanks for the proof. I am so fortunate to have Jim's product!

Attached photo is my audio sysytem,,,Pair of 600B with 622Bcabinet,sounded by RCA cunningham45 single LoftinWhite Power Amplifire ,Source is Sony WalkMan,MP3 player,,,Mmmm.

Many Thanks!