BC543 - very high-output cardioid subwoofer

  • Double-tuned, bass-reflex loaded cardioid-control subwoofer system
  • Triple 18” woofer with all-carbon cone for high pressure loading
  • 5.3" voice-coils for low power compression and accurate performance
  • Large, centrally-located vent for improved breathing and low compression
  • Selectable cardioid rearward rejection patterns with up to 42dB rearward rejection
  • SIS pre-wired for very high damping and further reduced distortion (with ALC)

Product description

The BC543 is a self-contained, high-output cardioid subwoofer system for both permanent and portable applications. It is designed to offer a very high output, tight and accurate sub-bass response, as low-frequency extension of any Alcons pro-ribbon system.

By means of a front and rear located woofer configuration, in combination with dedicated processing, the system offers selectable cardioid low-frequency pattern control and excellent rear rejection (up to 42dB), without the need for additional cabinets.

Two state-of-the-art 18” long-excursion woofers with 5.3-in. voice-coil with vented triple-spider frame, Neodymium motor structure and all-carbon-fibre cone and dust cap are mounted in a direct-radiating configuration, with centrally-located X-Venting™; Taking more than 25% of the baffle surface, this port is designed to maximise the system’s breathing capacity, while minimising port-compression. The excursion capabilities of the 18” design, extends the output by 3.5dB compared to traditional 18” designs (not included in SPLpeak spec).

On the rear side, a single state-of-the-art 18” long-excursion woofer with 5.3-in. voice-coil, Neodymium motor structure and all-carbon-fibre cone and dust cap is mounted in a direct-radiating configuration, with Flank-Venting™ port; This folded port design enables optimal reflex-breathing, under minimal baffle dimensions.

The BC543 in road version is fitted with 12 handles for easy logistics.

The BC543 is powered and controlled by the ALC amplified loudspeaker controller; The ALC offers system-specific drive processing with dedicated optimisation, power and excursion protection, and hybrid filtering.

The preset library contains BC543 settings for sub/bass/punch response curves, as well as different cardioid patterns for maximum rear-/side-ward attenuation.

Through the SIS™ (Signal Integrity Sensing) circuit, the cable-length and connector resistance between the BC543 and ALC is completely compensated (system damping factor >10.000), for further increased accuracy and controlled cone-travel, resulting in a tighter sub and bass response.

Dimensional drawing

Technical specifications

Frequency response 35 Hz - 150 Hz (+/- 3 dB)
29 Hz - (+/- 10 dB)
Sensitivity nominal 100 dB (40 Hz - 100 Hz)
Nominal impedance   4 ohms/front, 8 ohms/rear
Recommended drive Sentinel10 1 pce. per 2 ch
Nominal SPL peak 135 dB (Sentinel10 40 Hz - 100 Hz)
140 dB (comparative)
Dispersion H x V (hyper) cardioid

Physical specifications

System   subwoofer, bass-reflex
front + rear
Drivers LF   2x AW18.6NDC-8 18” X-vented™ (front)
1x AW18.6NDC-8 18” Flank-vented™ (rear)
Connectors   1x Speakon NL8 input
Physical dimensions   mm        inches
Height   1196         47.1
Width   596           23.5
Depth   976           38.4
Weight (approx.) BC543   135 kg   298 lb
                             BC543i   123 kg   271 lb
Warranty   6 years limited


Stay Tuned

Subscribe to the Alcons newsletter and stay tuned