Last Updated 6 hours ago
Filmmaking Dictionary: Number 4 / 48 kHz Sample Rate
Definition
A 48 kHz sample rate means an audio system records or plays 48,000 samples per second for each channel. It is a common production and delivery rate for film, television and video sound.
Sample rate describes how often the waveform is sampled. Bit depth describes how those sample values are represented. Neither is the same thing as the camera’s frames-per-second setting.
Frequency Range
Sampling theory places the highest representable frequency below half the sampling rate. For 48 kHz, that boundary is 24 kHz. Real converters use filtering around the usable band, so the numerical boundary is not a promise that every recorder captures perfectly up to that frequency.
The microphone, analog circuitry and the sound itself also determine what is recorded. A higher sample-rate label cannot restore frequencies or detail that the preceding signal path did not capture.
Advertisement
Working With Picture
A 48 kHz sound recording can accompany several picture frame rates. The audio sample clock and timecode settings serve different functions. Changing a project from 24 to 25 fps does not automatically mean the audio should be resampled to an arbitrary new value.
Some specialized workflows use deliberate pull-up or pull-down rates. Those require a shared plan between production and post. Do not change the recorder’s sample rate merely because a camera setting has a fractional number.
Practical Example
A dialogue recording made at 48 kHz is imported into an editing project expecting 48 kHz audio. Its timing remains correct when the file is interpreted properly. If software instead treats those samples as though they were recorded at 44.1 kHz, playback speed and pitch change.
Proper sample-rate conversion is different from relabelling the samples. Conversion calculates a new sample sequence while preserving the intended duration and sound; interpretation at the wrong rate changes what the existing samples mean in time.
Production Checks
- Confirm the required sample rate with post-production.
- Check bit depth and channel routing separately.
- Match the intended timecode and synchronization workflow.
- Inspect file metadata after a test recording.
- Avoid unnecessary conversions between departments.
- Review long recordings for drift when combining independently clocked devices.
Advertisement
Frequently Asked Questions
Does 48 kHz mean 48-bit audio?
No. Sample rate and bit depth are separate specifications.
Will 48 kHz automatically keep every device synchronized?
No. Independent clocks, timecode interpretation and other workflow errors can still cause problems.
Related Terms
Browse all terms starting with 4 or return to the filmmaking dictionary.