The JBL 4642A is a high-quality subwoofer system, featuring a technologically advanced 460 mm (18 in) low frequency transducers mounted in a direct radiator, bass-reflex enclosure for smooth response to the lowest audible frequencies. The 4642A is ideal for low frequency augmentation of either analog or digital soundtracks in motion picture theatres and for general sound reinforcement applications. The 2241H transducer utilizes the patented Vented Gap Cooling (VGC) process*, which pumps air through the magnetic gap and directly over and around the voice coil, providing immediate heat transfer and a reduction in operating temperature. This increases power handling while reducing power compression. Through the use of computer-aided magnet optimization and analysis techniques, JBL engineers were able to optimize magnet weight, flux density and field saturation, resulting in a 2.6 kg (6.5 lb) reduction in overall driver weight and a significant reduction in harmonic distortion. This magnet structure offers much of the weight advantage of rare earth magnet structures without the prohibitive cost, enabling the system to carry a 600-watt continuous AES pink noise power rating.

Product Features

• 950 W (60 Vrms) AES 100-hour rating; 1200 W (69 Vrms) AES 2-hour rating
• Usable response to 22 Hz (-10 dB) with no EQ; flat to 22 Hz (-3 dB) with external EQ
• 2241H VGC™ (Vented Gap Cooled) drivers provide long peak-to-peak excursion, high sensitivity and high maximum SPL capability
• SFG™ (Symmetrical Field Geometry) magnet structure for low 2nd and 3rd harmonic distortion
• Approved by Lucasfilm, Ltd. for THX® installations
• Finish: Black

Product Specifications

Component Electronics – Model 2241H

• Low Frequency Transducers: 2 x 2241H, 460 mm (18 in)
• Rated Impedance: 4 ohms
• Minimum Impedance: 3.2 ohms

Power Handling Capability

• Input Power Handling (AES 100-Hour Rating): 950 W (60 Vrms), IEC/pink
• Input Power Handling (AES 2-Hour Rating): 1200 W (69 Vrms), IEC/pink

Output Capability

• Half-Field Sensitivity: 40 Hz – 100 Hz; 100 dB, 1 W @ 1m; reference 2.0 V
• Max Continuous SPL @ 1 metre:
  • Single Module: 131 dB
  • Two Modules: 136 dB
  • Four Modules: 140 dB
• Max Peak SPL @ 1 metre:
  • Single Module: 137 dB
  • Two Modules: 142 dB
  • Four Modules: 146 dB
• Frequency Response:
  • Lower Frequency Limits (no EQ):
    • -10 dB: 22 Hz
    • -3 dB: 35 Hz
  • Lower Frequency Limits (with EQ):
    • -10 dB: 20 Hz
    • -3 dB: 22 Hz

Other

• Recommended Crossover Frequencies:
• High-pass: 20 Hz, 24 dB/octave or greater
• Low-pass: 80 Hz to 150 Hz, 12 dB/octave or greater
• System Polarity: EIA Standard. Positive voltage to RED terminal produces forward cone motion.
• Input Connectors: Colour-coded push terminals
• Net Weight: 96 kg (216 lb)
• Shipping Weight: 109 kg (240 lb)

Enclosure

• Materials and Finish: 19 mm (0.75 in) particle board with 25 mm (1 in) baffle and back panel; extensive bracing on all panels
• Enclosure Tuning Frequency: 25 Hz
• Net Internal Volume: 506 litres (18 cubic ft)
• Dimensions (H x W x D): 762 mm x 1219 mm x 610 mm (30 in x 48 in x 24 in)