The Northridge facility is an expansion of a former RCA manufacturing plant that was built in the 1950's. It sits on a 44 acre campus and was acquired by JBL in 1976. A major expansion occurred in 1977 that quadrupled the manufacturing space to 550,000 sq. ft. It began exclusively as a JBL facility and consolidated their previously disparate plant locations. In the last decade, much of the Harman International's product line was moved to this facility, as were the executive offices.
Our tour was arranged by Mark Gander and conducted by John Eargle. It began in JBL Professional's building that encompasses separate office and design facilities along with a dedicated manufacturing plant. It is sited in the extreme lower center building of the aerial photo. The manufacturing plant was in the middle of a major transition during our visit. Some of the production lines were in the process of being moved into the main manufacturing facility illustrated in the upper center portion of the photo. A new state-of-the-art production facility is being established that will ensure the highest levels of quality and productivity.
The tour began with a visit to the test facility where completed systems are measured. It is a huge dedicated room with a number of microphone placements connected to analysis equipment. Shown in the photo to the right is a broad cross-section of the current JBL Professional product line. To the right-front are examples of the latest EON® series. To the extreme left and right are JBL's HLA™ system. The tall systems along the back wall are JBL's new ScreenArray® cinema systems. There are also a couple of systems from JBL's Custom Shop.
This photo illustrates a soon-to-be-lost link to the past. Here a JBL employee is winding voice coils on a lathe originally designed by Jim Lansing. The process involves winding coils approximately 3" long on a mandrel. These are later cut into sections to produce a number of individual coils to be installed in drivers. This is a manual process that requires a degree of dexterity to quickly and evenly wind the coils. The new production line automates this process and coils are only wound to the length required for an individual driver.
This photo illustrates the assembly process for low-frequency drivers. Cones are attached to voice coils and spiders using adhesives and the assembly is installed in speaker baskets. Cone manufacturing is outsourced and the center of the photo shows stacks of cones waiting for installation. This line produced all of the low frequency drivers. Runs of specific models are scheduled for different times on this line. Switching between models takes very little time and largely involves ensuring that the required parts are on hand.
The high-frequency driver assembly line operates much like the low-frequency line. All models are produced on one line. The assembly process involves attaching the coils to titanium diaphragms, energizing magnets and attaching them to the phase plug /return structure assembly, and installing the diaphragms. Most manufacturing work on the phase plug and magnet structure has been recently outsourced. The downsizing of the defense industry in southern California resulted in significant unused capacity for precision metal working. This capacity was converted to commercial production and JBL soon discovered it was more effective to rely on this industry to supply production quantities of machined metal parts. JBL maintains an extensive tool room where both prototype designs and production fixtures are developed under the direct control of the R&D and Manufacturing engineers..
The photo at left should be instantly recognizable to any vintage JBL fan. It's the pot structure and phase plug for the 375 compression driver. A variant of the 375 with a phenolic diaphragm and without a phasing plug is still built for one customer - a fog horn manufacturer The horns are installed in floating navigation buoys that were designed many years ago. The design of the buoy is so compact that no other driver can fit. It is said that when the diaphragm wears out, it is cheaper to replace the entire driver since this work must be done at sea. The old drivers are literally tossed overboard. In other words, there are stockpiles of old 375 pot structures resting in a number of places at the bottom of the ocean.
The photo at right shows finished examples of JBL's current state-of-the-art in compression drivers. They are model 2435 drivers that were developed as part of JBL's new VerTec™ line array sound reinforcement system. The drivers employ a neodymium magnet structure with a three inch diameter coil attached to a beryllium diaphragm and uses a 1.5" throat exit. It is an extremely compact and precise unit that weighs only 2.5 lb. It is a very high-performance device with accuracy compatible for use in hi-fi applications.
JBL recently established a dedicated shop for the manufacture of custom systems for acoustical consultants and contractors. JBL has a long history of providing dedicated solutions for individual customers. This facility allows the efficient design and construction of specialized systems to meet any customer need. The entire manufacturing facility, including this shop, recently received ISO 9002 certification and is the only facility of its kind with this quality standard.
The photo at right illustrates one of three anechoic chambers at Northridge. This is part of the research facility that is shared by all loudspeaker divisions. This includes JBL Consumer, Infinity and Revel. These chambers, combined with their advanced instrumentation and analysis equipment, represents the most advanced research facility of its kind in the world.
This photo illustrates the smaller of two listening rooms associated with Harman Consumer's research facility. While JBL prides itself in designing to the most advanced scientific principles, the final arbiter remains listening. At time of our tour, the room was set up with JBL's latest home theatre system - the Performance Series. This system is Greg Timber's latest incarnation of a concept he pioneered in the L212 of 1977 and refined in the L250ti. The main speakers are a four-way system using a powered subwoofer containing the LE14H along with an 8" inverted dome mid-bass driver, 4" inverted dome midrange and titanium tweeter with integral wave guide.
© 2001 Don McRitchie