KRK Ergo Studio Monitor Room Processor ERGO doesnt color the sound or produce an artificially sterile environment. Large Volume Knob: Ultra-smooth response volume control provides simultaneous control of ERGO's A/B/Sub outputs. A Speakers: Enables or disables the audio being sent to the A speakers. B Speakers: Enables or disables the audio being sent to the B or subwoofer speakers. Room Correction: Turns room correction processing on or off.