JBL 8340 Studio Monitor

Name: JBL 8340
Brand: JBL

The JBL 8340 is a compact near-field studio monitor from JBL Professional's 8300 series, aimed at recording, broadcast, and video post-production work. It's a sealed (infinite baffle) design, which JBL said helped keep the bass tight and controlled. The enclosure is a dense, mineral-filled polypropylene, curved on the front baffle to cut down on diffraction.

The driver complement is a 6.5" woofer paired with a soft-dome tweeter (sources disagree on whether the dome is 0.75" or 1", and likewise on sensitivity — 87 dB vs 90 dB — so take those figures with some caution). The crossover sits at 1.2 kHz, and the speaker is rated for 25–200W into 8 ohms. Frequency response is stated as 50 Hz–20 kHz (±3 dB). It was designed to work with the optional JBL M552 electronic crossover, and the drivers are shielded so the monitor can sit next to video screens without causing interference. A 3-point wall-mount system was included, which tells you JBL saw these living in edit bays and broadcast trucks as much as in mixing rooms.

Pro Sound Review praised the 8340 for consistent imaging and a balanced response in professional use, and noted that owners report reliable performance when given adequate amplification. The thing to watch on a used pair is the woofer foam surrounds. They deteriorate with age, as they do on many JBL monitors of this era, and replacement surrounds are a common repair. The tweeters are generally regarded as durable, though some units may need replacement by now. No production years or original price have surfaced in the documentation, so the exact timeline for the 8340 remains uncertain.

Type: 2-way sealed (infinite baffle) near-field monitor
Drivers: 6.5" LF, soft-dome HF
Crossover: 1.2 kHz
Frequency response: 50 Hz – 20 kHz (±3 dB)
Power handling: 25–200W
Impedance: 8 ohms
Dimensions (H×W×D): 15" × 9.5" × 9.75"
Weight: 18 lbs