Don McRitchie
12-02-2004, 04:06 PM
The recent "375's Not" thread made me realize that I have limited info on the above two drivers that I have not shared before and may be of interest. These drivers showed up in some number around five years ago on Ebay from a decomissioned facility at the White Sands missle range. They were auctioned as hi-fi drivers, but were anything but. They were made by JBL in the late 50's and early 60's for an independent company owned by William Thomas called Transducers Inc. This company produced drivers and systems intended to simulate the vibration and accoustic energy of missle launch conditions as part of the design and testing of missle parts. They were intended for high energy and not linearity. Both drivers were painted blue and are easily confused with the JBL hi-fi versions from around 1960.
To be honest, I am not sure about the construction differences between the 375H and a standard 375. The 150H is more obvious. It used the 130A chasis with a cone from an LE15 and a corrugated surround. I saw a couple of these mislabeled as 150 drivers from the Hartsfield, to which they bore no relation. JBL would use the 150H designation much later as the rebadged E145 used in the Everest.
To be honest, I am not sure about the construction differences between the 375H and a standard 375. The 150H is more obvious. It used the 130A chasis with a cone from an LE15 and a corrugated surround. I saw a couple of these mislabeled as 150 drivers from the Hartsfield, to which they bore no relation. JBL would use the 150H designation much later as the rebadged E145 used in the Everest.