JBL T420 (1978–1981)
The JBL T420 is a compact two-way bass reflex loudspeaker that JBL produced from 1978 to 1981 — a period that also saw Jensen fielding its own T-series car speakers, though the JBL T420 was strictly a home bookshelf design. A contemporary trade publication noted Jensen's T-420 as a 6 1/2-inch two-way car speaker rated at 75 watts (High-Fidelity-Trade-News, March 1983, p.25). The same issue reported Jensen's T-545 as a 6-by-9 inch three-way speaker rated at 100 watts (High-Fidelity-Trade-News, March 1983, p.25). The same issue reported Jensen's T-545 as a 6-by-9 inch three-way speaker rated at 100 watts (High-Fidelity-Trade-News, March 1983, p.25). It paired an 8-inch woofer with a 1-inch dome tweeter, crossed over at 500 and 3,500 Hz. The original German list price was DM 478 per pair.
The documented specs are consistent across the two sources that cover this model. Nominal impedance is 8 ohms, sensitivity is rated at 88 dB/W/m, and frequency response extends from 55 Hz to 22 kHz. Power handling is listed at 30 watts continuous and 60 watts music. The cabinet measures 235 × 440 × 210 mm (W×H×D) and weighs 8.2 kg.
The one detailed review found — in the German publication Audio-Dimension — was largely positive. The reviewer noted that despite the conservative 30-watt rating, the T420 could be driven with up to 100 watts without concern. The overall character was described as very balanced, with no harshness; the compact enclosure yielded somewhat restrained bass, but that bass was judged precise. Sound was characterized as pleasant, open, and unobtrusive, with particular strength in classical and jazz.
- Type: 2-way bass reflex, compact/bookshelf
- Drivers: 8" woofer, 1" dome tweeter
- Crossover: 500 / 3,500 Hz
- Impedance: 8 ohms
- Sensitivity: 88 dB/W/m
- Frequency response: 55–22,000 Hz
- Power handling: 30 W continuous / 60 W music
- Dimensions: 235 × 440 × 210 mm (W×H×D)
- Weight: 8.2 kg
- Original price: DM 478 per pair
Nothing is documented about the T420's place in the JBL lineup, cabinet construction, crossover components, or common service issues. No collector market data has surfaced either — only the original late-1970s price. What the record shows is a competent, well-reviewed compact speaker from a four-year production run, with both sources agreeing on every shared specification.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Related Models
- JBL 075
- JBL 077
- JBL 120Ti
- JBL 124A
- JBL 124H
- Braun AUDIO-1 (1965)
- Braun AUDIO-250 (1965)
- Magnavox Component Systems (1972)
- Acoustic Research AR (1967-1976)
- Acoustic Research 11