The Carbon Special Black Label sits at the pinnacle of REL Acoustics' Serie S range, bringing Reference-level technology into a medium-scale chassis. Positioned directly below the flagship No.31 and No.25 Reference Series subwoofers, it delivers extraordinary speed, nuance, and depth at a fraction of the Reference price, making it suitable for the most demanding two-channel and home cinema installations.
Carbon Fibre Driver Technology
At the heart of the Carbon Special Black Label is a 12-inch long-throw carbon fibre active driver with an inverted carbon fibre centre cap and a die-cast alloy chassis. Carbon fibre offers an exceptional combination of stiffness and low mass, allowing the driver to track transients with precision that conventional materials cannot match. A matching 12-inch carbon/carbon flat cone passive radiator fires downward, tuned to work in concert with the active driver to extend bass reproduction to -6dB at 19Hz whilst preserving the speed and articulation that defines the REL house sound.
Linear Class D Amplification
Power delivery comes from REL's proprietary Linear Class D amplifier design, which combines a Class A/B power supply and current delivery stage with a Class D output stage. The result is 900 watts RMS continuous power, with the ability to sustain peaks of 1,250 watts, driven by a substantial power transformer with extensive heatsinking. This architecture eliminates the switching artefacts sometimes associated with conventional Class D designs whilst delivering the efficiency advantages that allow the amplifier to remain cool under sustained high-output conditions.
Connectivity and Integration
REL's signature High Level Input, using a Neutrik Speakon connector, connects directly to the speaker terminals of the main power amplifier. This method of connection preserves the timing, tonal character, and gain structure of the main amplifier, ensuring the subwoofer integrates seamlessly with the rest of the system rather than functioning as a separate, disconnected bass source. A full suite of low-level inputs is also provided: two RCA inputs, one LFE RCA, and one LFE XLR, alongside matching loop-through outputs. The variable crossover covers 20Hz to 120Hz for the high-level channel. The Carbon Special Black Label is also compatible with REL's AirShip Direct wireless transmitter, enabling flexible placement without signal degradation.
Cabinet and Finish
The cabinet is finished in eight coats of piano black lacquer and is supplied with a premium handcrafted wood grille as standard. Each wood grille features unique grain variations due to the natural materials used. A black cloth grille is available separately. Recessed stainless-steel handles and knurled billet cylinder feet provide practical handling and levelling. The Carbon Special Black Label is also engineered to support line array stacking, allowing two or more units to be combined vertically for expanded dynamic range and room coverage in larger spaces. REL is headquartered and assembled in Bridgend, Wales, United Kingdom.