R18S is a professional active stereo subwoofer engineered to enhance Montarbo B and R series full-range speakers. Its 18” low-frequency driver with 4” voice coil delivers deep, precise bass down to 41 Hz, providing the low-end foundation required for music, live performance, and portable PA systems. The system reaches a maximum SPL of 131.5 dB, ensuring impact and clarity across small to medium venues.

Powered by a Class D amplifier platform rated at 500 W RMS / 1000 W peak, R18S offers responsive low-frequency output with ample headroom. Its passive radiator design ensures extended low-end performance while eliminating the need for active cooling, making it highly reliable for repeated transport and prolonged use.

Onboard DSP—including 28/56-bit processing and 24-bit / 48 kHz AD/DA conversion—provides precise control over level, crossover frequency, and polarity, enabling smooth integration with main PA speakers. Connectivity includes dual Combo inputs for stereo operation and XLR line output for LINK + XOVER configuration, facilitating flexible system expansion and multi-subwoofer setups.

Constructed from multilayer wood with protective polyurea finish, the cabinet is designed for durability and ease of transport. Measuring 510 × 650 × 690 mm and weighing 38 kg, R18S delivers professional-grade low-frequency reinforcement while remaining practical for portable and touring applications.