Selectable Playback EQ
Selectable playback EQ means a cassette deck has a separate control for choosing its 120 or 70 microsecond playback equalization.
Playback equalization restores the intended frequency balance. A separate selector chooses the playback time constant independently of tape-type or recording-bias selection. It differs from a listener’s bass or treble control.
Selectable Playback EQ — Cassette Deck
A separate EQ selector is useful when the recorded equalization needs to be chosen independently of the cassette's material or detection notches. The appropriate setting follows how the tape was recorded. Choosing the wrong time constant changes the reproduced tonal balance, rather than merely changing recording bias.
Compare whether the deck provides an independent playback EQ control or couples equalization to one tape selector. Automatic selection can support both time constants without offering this independent choice. A bias-fine-adjust control concerns recording and does not establish selectable playback EQ. Check the recording information rather than selecting a setting simply because it sounds brighter.