Floorstanding loudspeakers — JBL PROJECT EVEREST DD67000

The Project Everest DD67000 is a three-way floorstanding system from JBL of Northridge, California, developed as a further evolution of the Project Everest DD66000 that marked the company's 60th anniversary. It belongs to the JBL Project line, a sequence of no-limits designs that began with the Hartsfield of 1954 and continued through the Paragon, the original Everest DD55000 of 1986 and several K2 models. JBL describes the layout as an augmented two-way, with a single midrange crossover in the tradition of its 1950s and 1960s horn systems. It dates from 2012, and finishes are rosewood or maple.

Key specs that matter

Two 15 inch (380 mm) 1501AL-2 woofers sit below a 476-series compression driver with a 4 inch (100 mm) pure-beryllium diaphragm, and a 045-series 1 inch (25 mm) beryllium unit covers the ultrasonic range. The first woofer runs to 150 Hz with a 6 dB per octave slope, the second reaches 850 Hz where it meets the horn at 24 dB per octave, and the ultra-high-frequency driver joins at 20 kHz. Response is 29 Hz to 60 kHz in half space (45 Hz to 60 kHz anechoic) at -6 dB. Sensitivity is 96 dB for 2.83 V at 1 m, and the 8 ohm nominal impedance falls to 5.0 ohm at 80 Hz and 3.0 ohm at 40 kHz. Each cabinet is 965 mm high, 1109 mm wide and 469 mm deep and weighs 137 kg bare or 142 kg with its grille.

Engineering and use context

The woofers pair a pulp sandwich cone with a foam-injected core, a pleated cloth surround and dual inverted Nomex spiders. Their long edge-wound aluminium voice coils work in an underhung gap fed by an Alnico 5DG magnet, with a shorting ring and copper-steel top plate against demagnetising and eddy-current distortion. Each coil is wound for double impedance so the two woofers still present the rated nominal impedance. Bi-Radial horns set dispersion at 100 x 60 degrees for the main driver and 60 x 30 degrees for the 045, whose phasing plug is pure magnesium. The curved MDF enclosure uses an inner birch plywood baffle and an outer baffle covered in carbon-fibre cloth, with SonoGlass horn lips. Two 4 inch flared ports on the rear are tuned to 31 Hz.

Pairing

JBL asks for 100 to 500 W from an amplifier with high current capacity that can drive a low-impedance load. Separate LF and HF input terminals on the rear make bi-wired or bi-amplified connection possible, and front panels provide three-position LF and HF level controls, drive-mode bars and left or right orientation bars.

Alternatives

The JBL Project Everest DD65000 is the companion floorstanding model built on the same platform, with 1501AL-1 woofers, a 750 Hz midrange crossover and 32 Hz port tuning.