Once blackout mode is on and a tape is playing, Audionix waits for five seconds without a touch. Then the screen fades to black over a little under a second. When it comes back, it shows only the deck or the cassette, in landscape.
Waking it up
Tap anywhere and the player returns. It works every time, which sounds like it shouldn't need saying, but a screen you can't wake is worse than a bright one. The five-second timer starts again from your last touch.
Where it fits
A phone on a nightstand. A speaker on a shelf and a phone leaning against it. A long drive with the phone in a dock. In any of these you want the music and not the glow.
It pairs well with cassette view, since a lone tape with turning reels is a nicer thing to wake up to than a menu.
Blackout fades the screen, it doesn't pause anything. Your tape keeps playing the whole time.