The black Yamaha CXS18XLF is a passive subwoofer designed for extending the low frequency of full-range speakers and is well suited for use with any of the CZR-series powered loudspeakers. The subwoofer requires 1000W of power to drive the 18" woofer, providing a frequency range of 32 Hz to 150 Hz (-10 dB) with a maximum SPL of 133 dB.

Yamaha recommends the use of a DSP speaker processor or a power amplifier with integrated DSP, such as Yamaha's PX Series amplifiers, in order to set crossovers, limiting, and equalization to ensure the best performance. Additionally, two or more subwoofers can be deployed with a cardioid configuration (DSP dependent), which can effectively reduce stage volume, while increasing low-end output directed at the audience. The rear panel offers three Neutrik speakON NL4MP connectors, which are configured with two input/parallel connectors for multiple subwoofers plus one output connector for flexible set up to full-range CZR loudspeakers or cardioid mode setting. The Yamaha CXS18XLF is equipped with both a 35mm pole socket and an M20 threaded socket to support a full-range cabinet.