CB181sl - Shallow subwoofer system

  • single 18” long-excursion woofer with vented-spider
  • space-economic design: cabinet depth only 11”/27.5cm
  • lowest usable frequency 25Hz.
  • power handling 1.000W RMS, 6.000W peak
  • SIS pre-wired for very high damping and speaker cable compensation (with ALC)
  • large, side-placed vents for improved flow capacity without moving the screen
  • dedicated (excursion) protection in combination with SDP modules (with ALC)

Product description

The CB181sl is a direct-radiating slim subwoofer system for demanding cinema applications, delivering tight and accurate bass and sub response with very low distortion.
It is designed to meet all requirements of current and future (Digital) Cinema sound formats.

The direct-radiating 18” long excursion woofer with large, 4” voice-coil is mounted in an optimally vented chamber, with a large bass reflex port for excellent breathing capacity, increasing overall output while minimising port-compression. Specific attention has been paid to obtain a linear response in the operating bandwidth, while handling low frequency transients with maximum control.

The ultra-slim enclosure design provides for stacking, flying or wall-mounting. The side-oriented reflex vent enables the cabinet to be closely mounted behind the screen without chance of screen resonance. The CB181sl is also available with front-venting for in-wall baffle mounting (“FV” version).

For full system performance, the CB181sl is to be driven and controlled by the ALC amplified loudspeaker controller; Driven by the ALC, the CB181sl delivers maximum sound quality and output power with long-term operation reliability. The integrated factory presets in the drive processor of the ALC offer gain, phase and filtering matching.

The Signal Integrity Sensing™ pre-wiring ensures complete cable/connector compensation between the CB181sl and the ALC amplified loudspeaker controller, significantly increasing response accuracy, regardless of cable length and system impedance. Especially with the cinema-typical long speaker cable runs and the subwoofer system’s possible low impedance, the effect is remarkable, resulting in really tight and accurate reproduction for even the lowest octaves.

Due to its form factor, the CB181sl is designed as low frequency extension in medium-to-large cinema systems, but is also the ideal choice for the Rear-Subwoofer channel in immersive surround systems.

Dimensional drawing

Technical specifications

Frequency response 27 Hz -    (+/- 3 dB)
20 Hz -    (+/-10 dB)
Sensitivity nominal 96 dB (40 Hz – 100 Hz)
Nominal impedance 8 ohms
Recommended drive     Sentinel3 min., max. 2 pce. per channel (4 ohms)
Nominal SPL peak 123 dB (Sentinel3 40 Hz – 100 Hz)
128 dB (Sentinel10 40 Hz – 100 Hz)
Dispersion H x V omni

Physical specifications

System subwoofer, front loaded
Drivers LF 1x AW18.4-8 18”, side-vented
Connectors 2x Speakon NL4 input
Physical dimensions      
Height 1200 mm / 47,2 inch
Width 1000 mm / 39,4 inch
Depth 275 mm / 10,8 inch
Weight (approx.) 72 kg / 159 lb
Warranty 6 years limited

Stay Tuned

Subscribe to the Alcons newsletter and stay tuned