JBL T425

Name: JBL T425
Brand: JBL

Very little is documented about the JBL T425. The record shows one surviving artifact: a printed service manual, THX-62156, revision B, with the JBL name and a JBL Incorporated copyright line. Nearly everything confirmed about this model comes from that manual.

The circuit diagrams show a passive loudspeaker system with an internal crossover built from multiple capacitors, inductors and resistors. The crossover frequencies are given as 1500 Hz, 3000 Hz and 10 kHz, so it is a three-way dividing network. The parts list names the driver assemblies only by JBL part numbers (40040, 40041, 40042, 40090). It gives no sizes, types or counts. The manual also has an exploded-view parts diagram, but the source text describes no construction details at all - no cabinet type, material, porting or finish.

High-Fidelity-Trade-News (January 1983, p.55) noted that JBL planned additions to each of its three consumer loudspeaker lines. The T425 is not named in that brief mention. A later Audio (May 1985, p.122) speaker roundup lists a JBL model in a specifications table, but the OCR of that page is too fragmentary to attribute any figures to the T425 with confidence.

Beyond the manual, almost nothing else is recorded. Production years, original price, weight, dimensions, power handling, and driver configuration are all unstated in the available sources. Whether the T425 was a consumer, professional, or studio model is not documented. No owner reviews, market prices, or repair notes have surfaced. A hifiengine listing table shows 8 ohms impedance, 91 dB sensitivity, and a 37 Hz–40 kHz frequency response, but those values are not clearly attributed to the T425 rather than another model on the same page, so they cannot be treated as confirmed.

Known from the service manual: