MartinLogan's PBK Perfect Bass Kit allows you to run Anthem Room Correction (ARC) with compatible MartinLogan speakers and powered subwoofers. Each kit is shipped with a unique microphone. Why use the PBK Kit? Because even when a MartinLogan subwoofer or speaker is ideally placed in your room, the dynamics of each listening environment present a unique challenge for bass performance. The MartinLogan Perfect Bass Kit (PBK) learns vital information about your unique space, transforming the performance for perfect bass, every time. The PBK system employs your Windows PC, connected via USB to a microphone and your MartinLogan speaker or subwoofer, to identify problem areas in your listening environment. The PBK processes information from multiple data points and configures the optimal solution, achieving pinpoint-accurate room response. PBK optimizes the bass performance of the Dynamo 1500x, BalancedForce 210, BalancedForce 212, and other compatible MartinLogan powered subwoofers. It also allows you to use the free Anthem Room Correction (ARC) app with compatible electrostatic speakers in MartinLogan's Masterpiece Series. For using the PBK Kit with compatible MartinLogan Masterpiece Series electrostatic speakers, you will also need appropriate software. Anthem Room Correction (ARC) come in two flavors, ARC Genesis (for Mac and PC) and ARC Mobile (for iOS and Android), and both are free for download. ARC Genesis offers a full-featured demo mode that you can try for free today. See the MartinLogan website for more information.