DBX RTA-M. The optional RTA-M real-time audio analysis microphone is the perfect accessory for the DriveRack PA (PA, PX, PA+, PA2) and 260 series. Used with the system setup wizard and the auto-EQ wizard, the RTA-M is ideal for optimizing sound quality even in the most challenging acoustic environments. The RTA-M is a flat frequency response measurement microphone, specially designed for the Driverack series to capture all frequencies from 20 Hz to 20 kHz, ensuring accurate real-time audio analysis. It operates with phantom power (supplied by the Driverack units) and comes equipped with a clip and a case.