JBL 077 (mid-1970s – early 1980s)

Name: JBL 077
Brand: JBL

The JBL 077 is a ring-radiator tweeter. It is a compression driver that puts out sound through a radial slot instead of a dome or cone. It belongs to JBL's family of ring-radiator "super tweeters" with the 075, 076, and 2405. It was the high-frequency driver in two of JBL's most respected systems, the L300 Summit loudspeaker and the 4333 studio monitor. Enthusiast sources describe it as one of the great JBL ring radiators from the mid-1970s, and it's widely regarded as one of the finest super tweeters of its era. A 1974 review in Audio (October 1974, p.11) noted that traditional tweeters narrow their range at higher frequencies, a problem the ring-radiator design was intended to address.

What's documented about the 077's performance comes largely from database entries and owner reports. HiFi Engine lists a frequency response of 650 Hz to 21 kHz, sensitivity of 90 dB at 1W/1m, power handling of 50W, and 8-ohm impedance. The 650 Hz figure is the usable range as a tweeter, not a crossover recommendation. In the L300 Summit, the crossover point was around 850 Hz per Lansing Heritage's description. The 077 uses an alnico magnet in its original form, though replacement motors with ferrite magnets exist in the repair market.

The record contradicts itself on where the 077 sits in JBL's lineup. Lansing Heritage states the 077 was introduced to replace the 075. HiFi Engine's database lists the 077 as replaced by the 075. Both can't be right, and without a period catalog or service manual to settle it, the question stays unresolved. The 077 was discontinued in the early 1980s.

Collector interest in the 077 remains strong. Current listings show pairs at $350 - $600 and single units at $200 - $325. Diaphragms are rare, expensive, and prone to drying out and cracking. Aftermarket diaphragms from China exist but draw skepticism from purists. Anyone considering a pair should factor in diaphragm condition, since replacement cost can rival the purchase price.

Known specs: