Bookshelf Speakers — JBL 4349

The JBL 4349 is a 12-inch (300 mm) two-way studio monitor loudspeaker sold under the JBL Synthesis name by Harman International. It follows the classic JBL studio monitor layout, with a large horn above a big paper-based woofer on the front baffle, and it is priced at USD 7,500 per pair. The Studio Monitor Series around it runs from the 4306 bookshelf model up to the 4367 floorstander. The 4349 is supplied in satin walnut wood veneer with a blue grille or satin black walnut wood veneer with a black grille.

Key specs that matter

Nominal impedance is 8 ohms, and JBL recommends amplifier power of 25 to 200 W RMS. Sensitivity is 91 dB measured with 2.83 V at 1 m. The quoted frequency response runs from 32 Hz to 25 kHz, specified at -6 dB. A single crossover splits the signal at 1.5 kHz. With the grille fitted each cabinet measures 736.6 mm high, 444.5 mm wide and 342.6 mm deep, and it weighs 37.7 kg.

Engineering and use context

High frequencies come from the patented D2415K compression driver, which uses a dual 1.5-inch (38 mm) design. JBL describes the result as a very efficient design and explains that the D prefix stands for dual diaphragms, dual voice coils and dual motors inside one driver body. The compression driver loads into a patented HDI horn precision-moulded in Sonoglass, an inert moulded material whose hair-like internal structure JBL says helps break up resonances. Below the crossover point a 12-inch cast-frame bass unit with a Pure-pulp cone and a 3-inch voice coil takes over. The enclosure is heavily braced and built with 25 mm thick walls. Its bass-reflex tuning uses two front-firing, computer-optimised flared ports, so the rear panel has no port opening. Two tone controls sit on the front panel below the horn - one for the high-frequency band and one for the ultra-high-frequency band - so the upper range can be trimmed without turning the cabinet around.

Pairing

Around the back are two sets of gold-plated terminals linked with shorting straps. With the straps in place a single amplifier channel drives the whole speaker, and with them removed the bass section and horn can be bi-wired or fed by two separate amplifier channels.

Alternatives

The JBL 4309 Studio Monitor is a more compact two-way bookshelf design that pairs the 2410H-2 1-inch compression driver and an HDI horn with a 6.5-inch Pure-pulp woofer in a cast frame.