The Mackie CRDV is a desktop volume controller built specifically for use with the Mackie CR8S-XBT subwoofer and a pair of powered monitors. It utilizes a space-saving concentric design that allows separate volume control for your sub and stereo speakers. The CRDV features an attached cable with a 1/4" male plug for easy hookup to your CR8S-XBT subwoofer.