Developed for JBL Pro, a set of four internally amplified speakers. The face of the speaker was aluminum die cast. A heat sink stretched across both fined port tubes to which the amplifier’s FETs were attached. Heat from the amplifier was conducted into the fined port tubes. The voice coil moves the sub-woofer’s cone changed the internal volume of the speaker. This draws air in and pushes air out through the fined port tubes. This provides natural cooling to the amplifier.
The front, cone frame, fined port tubes and horn were a single die cast aluminum part. The back housing was injection molded structural foam. The bezel and handle were injection molded plastics. The grill was drawn perforated metal.
JBL had a very tight schedule with the NAMM show quickly approaching. To produce 300 prototypes we turned to V-Process casting to replace the die cast front because of tooling lead-time issues. Once assembled in the JBL factory the initual speakers received a favorable review by the JBL “Golden Ears”.
The die cast front was a large part and there was only one die caster on the West coast at the time who had a press large enough. Again, time was short and bringing this tool up for production had its challenges. Our principle engineers were on the floor of the die caster for two straight day until it was in full production.
This speaker line won product of the year at the NAMM show.