The RS56 from Waves is a plug-in based on the passive equalizer from Abbey Road Studios. The RS56 Universal Tone Control was originally introduced in the early '50s and used to prepare recordings for the record-lathe, as part of the mastering process. Later, Abbey Road's pop engineers began using the unit for studio recordings because of its abilities to dramatically manipulate sound.
The EQ features three bands, each with four selectable center frequencies and six filter types, plus independent or linked control over the left and right channels. The plug-in operates in mono, stereo, and mid-side modes. The plug-in includes both Native and SoundGrid licenses.