The JBL Eon Baffle Speaker Story
The "Rest of the Story"
By: Bob McClintic
For full technical information on the JBL Eon speaker open the following link. (PDF)
JBL 15" EON Baffle Technical Specifications
Actual speaker dimensions: (H x W x D); 27 in x 17 x 17.5, (686 mm x 430 x 444 mm)
And Now, The "Rest of the Story"
(Or, how to give birth to a twenty pound speaker)
The Eon baffle was one of the most difficult aluminum castings I have ever produced. But let me tell you how it all started.
In 1993 I was appointed Technical Director for a company based in Grand Rapids, Michigan. One of the divisions was located in Los Angeles, California.
In 1994 I was invited to the Northridge, California headquarters of Harmon/JBL to assist their chief designer in the development of a totally new speaker concept. The casting was larger than anything that had ever been undertaken by our company or by JBL. The speaker design was innovative in numerous ways. Components were selected, not for economy but for light weight and performance. The end product was to be a self contained high performance speaker that an entertainer could pick up and check as baggage without assistance. Furthermore, air generated by the speaker moving through the ports would be used to cool the internal components. The harder it worked, the more it cooled itself.
To add a little humor to the project, it was code named the Simpson project with the two speakers being named Bart and Homer after the Simpson cartoon on TV. The names were selected because the profiles somewhat resembled those of the cartoon characters. Homer was the larger 15" speaker, Bart the smaller, 10" speaker.
I provided key casting design guidelines to the designer who then disappeared to his office for a few months to complete the design.
The local staff continued to manage the project as the die cast mold was built and preparations were underway to process the castings.
Meanwhile, I carried out assignments in other divisions.
Now, we'll fast forward to the arrival of the completed mold.
Homer gained a little weight during the construction of the mold as there continued to be innovations and changes. So many that years later when it came time to build a replacement mold, there was not one completed design, but an original with pages and pages of additions and modifications.
The casting that began as a fairly plain flat casting, had now become rounded, deeper, more complex and about 25% heavier than the original concept. (Finished weight was 14 pounds (6.35 kilograms). The complete "shot" weighted around 20 pounds, (9.07 kilograms).
When the tool arrived, the entire attention of JBL was on the die cast company to produce the initial sample parts. Coincidentally, it also happened that the President/C.O.O. had scheduled a staff meeting of all the Directors and Vice Presidents at the California site. The local staff had been struggling for several days to produce a usable casting, all under the watchful and growingly impatient eyes of the President of JBL and his staff of purchasing, engineering, manufacturing and quality. Finally, my boss asked me and two other directors to excuse ourselves from the staff meeting and assist in the start up. For a couple of days, we worked with the operators and technicians as we experimented with various approaches. On Thursday we decided to take turns covering the project for 24 hours until we achieved success. I drew the short straw and remained through Thursday second and third shifts (3:00 pm to 11:00 pm and 11:00 pm to 7:00 am). Working alongside with the operators and supervisors we experimented with various machine settings and tool modifications. Finally at around 2:30 am on Friday morning, we made the first successful casting. Little by little, we zeroed in on a process that worked consistently. When the office staff started arriving on Friday morning around 7:30 am, we had over 50 good parts to show them and more being produced. The JBL staff arrived to find numerous good castings and almost immediately returned to their home office to resume their normal duties.
Since then the castings have been produced on a daily basis and life returned to normal for a while. (To see what happens next click here).
