Data transfer rate per second in audio or video — 320 kbps is streaming standard, 1411 kbps uncompressed CD audio. Higher = better quality, larger files.
On set or in the post-production workflow, you constantly encounter this metric without always naming it. Bits Per Second (bps, or with prefixes: kbps for kilobits, Mbps for megabits) describes how much digital information flows through your audio track per unit of time. The higher this value, the more data your audio files transport — and thus usually better sound quality and larger files.
In practice, you distinguish between constant (CBR) and variable (VBR) bitrates. CBR provides you with a stable, predictable file size; VBR intelligently adjusts the amount of data: quiet passages require fewer bits, loud or complex sections get more. When mastering for different output formats, you make conscious choices: streaming platforms often only accept 128–320 kbps because end-users have limited bandwidth. In cinema or for Blu-ray, you work with 384–448 kbps and upwards, sometimes also with uncompressed PCM at 1411 kbps (which is the CD standard format). For your own working files in the editing suite? 48 kHz, 24 bit, uncompressed — that's around 2304 kbps. Don't skimp on bitrate here.
The most common mistake: underestimating file compatibility. A streaming provider that requires 320 kbps MP3 will accept your 192 kbps export file, but the client will notice it when listening. Conversely, you waste storage space if you export at 512 kbps for a YouTube video — YouTube will compress it downwards according to its own rules anyway. Modern codecs like AAC or Opus deliver better results at lower bitrates than older MP3 algorithms, but the industry remains sluggish with format changes. Bitrate settings play no role on the mixing console or in your DAW — you work in floating-point precision. You only have to commit when bouncing or exporting.
Practical tip: Always save your masters in two versions. One uncompressed or losslessly compressed (FLAC, WAV) for archives and potential future use. A second one, already downscaled to the target format (with the required kbps), for immediate delivery. This way, you avoid double encoding quality losses and have peace of mind.