DAT tape speed varies depending on the sample rate used for recording or playback.
The speed at which Digital Audio Tape (DAT) moves past the tape head depends on the digital audio sample rate being utilized by the DAT machine. This variation in speed allows for different audio quality and recording times.
Here are the typical tape speeds for standard DAT machines based on their operational sample rates:
| Sample Rate | Tape Speed |
|---|---|
| 48 kHz | 8.15 mm/s |
| 44.1 kHz | 8.15 mm/s |
| 32 kHz | 4.075 mm/s |
As shown, DAT machines operating at 48 kHz and 44.1 kHz sample rates transport the tape at a speed of 8.15 mm per second. This is the standard speed used for professional and consumer audio recording, offering high fidelity.
For applications requiring longer recording times or lower bandwidth audio, such as radio broadcasting (though less common now), DAT machines running at a 32 kHz sample rate use a slower tape speed of 4.075 mm per second. This half-speed mode effectively doubles the recording time available on a single tape.
It's important to note that while the linear tape speed varies, the head drum in a helical scan recorder like DAT spins at a constant high speed (typically 2000 RPM) to achieve a high relative speed between the head and the tape, which is crucial for recording the digital data stream. The listed speeds refer specifically to the linear movement of the tape reel-to-reel.
