JBL 4645C Single 18 inch Subwoofer System, 800W @ 8 Ohms

The JBL 4645C Single 18 inch Subwoofer System, 800W @ 8 Ohms is a high-quality subwoofer system, featuring a technologically advanced 460 mm (18 in) low frequency transducer mounted in a direct radiator, bass-reflex enclosure for smooth response to the lowest audible frequencies. The 4645C is ideal for low frequency augmentation of either analog or digital soundtracks in motion picture theaters and for general sound reinforcement applications. The 2242H 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.
The 2242H utilizes a rugged 100 mm (4 in) diameter voice coil and incorporates a large motor structure with a pole piece that extends both above and below the top plate to improve gap flux symmetry and increase thermal conductivity. This magnet structure and the use of a voice coil with one-third more exposed area than in former designs, provides the 2242H with very effective heat sinking, enabling the system to carry an 800 watt continuous AES pink noise power rating.

JBL 4645C Single 18 inch Subwoofer System, 800W @ 8 Ohms Features

- 650 W (72 Vrms) power handling (100-hour AES rating), 800 W (80 Vrms) power handling (2-hour AES rating)
- Usable response to 22 Hz (-10 dB) with no EQ; flat to 22 Hz (-3 dB) with external EQ
- 2242H SVG (Super Vented Gap) driver provides long peak-to-peak excursion, high sensitivity and high maximum SPL capability
- SFG (Symmetrical Field Geometry) magnet structure for extremely low 2nd and 3rd harmonic distortion
- Approved by Lucasfilm, Ltd. for THX installations

JBL 4645C Single 18 inch Subwoofer System, 800W @ 8 Ohms Specifications

- Low Frequency Transducer: 1 x 2242H, 460 mm (18 in)
- Rated Impedance: 8 Ω
- Minimum Impedance: 7.2 Ω
- Input Power Handling (AES 100-Hour Rating): 650 W (72 Vrms), pink/IEC
- Input Power Handling (AES 2-Hour Rating): 800 W (80 Vrms), pink/IEC
- Sensitivity: 40 Hz - 100 Hz, 97 dB, 1 W @ 1m; reference 2.83 V
- Max Continuous SPL @ 1 meter:
  - Single Module: 126 dB
  - Two Modules: 132 dB
  - Four Modules: 137 dB
  - Eight Modules: 141 dB
- Max Peak SPL @ 1 meter:
  - Single Module: 132 dB
  - Two Modules: 138 dB
  - Four Modules: 143 dB
  - Eight Modules: 147 dB
- Frequency Response, Lower Frequency Limits (no EQ):
  - -10 dB: 22 Hz
  - -3 dB: 35 Hz
- Frequency Response, Lower Frequency Limits (with EQ):
  - -10 dB: 20 Hz
  - -3 dB: 22 Hz
- Recommended Crossover Frequencies:
  - High-pass: 20 Hz, 12 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: Color-coded push terminals
- Net Weight: 63 kg (138 lb)
- Shipping Weight: 69 kg (151 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: 225 liters (8 cubic ft)
- Dimensions (H x W x D): 1010 mm x 674 mm x 450 mm (39.75 in x 26.50 in x 17.75 in)