Twin-Deck Recording
Twin-deck recording identifies which cassette wells can record and whether both can record the same source at the same time.
One well may be playback-only while the other records, both may record individually, or simultaneous recording may be available. The well labels can vary between machines.
Twin-Deck Recording — Cassette Deck
The distinction matters when dubbing or making two copies from an external source. A playback-only well can supply the original cassette while the recording well makes the copy. If both wells record simultaneously, the deck can put the same source onto two tapes in one pass.
Compare the supported recording arrangement, not just the presence of two cassette openings. Two record-capable wells do not necessarily operate together, and dubbing does not establish simultaneous external-source recording. The label “Deck B only” describes the one-recording-well arrangement even when the maker uses different labels. Single-well machines do not have this capability distinction.