CBR: An Explanation of Constant Bit Rate

A brief look at CBR encoding in digital audio

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Constant Bit Rate is an encoding method that keeps the bit rate the same as opposed to VBR which varies the bit rate. CBR processes audio faster than VBR due to its fixed bit rate value. The downside to a fixed bit rate is that the files that are produced are not as optimized for quality vs. storage as VBR. For example, if there is a quiet section of a music track that doesn’t require the full bit rate to produce good quality sound then CBR will still use the same value - thus wasting storage space.

The same is true for complex sounds; if the bit rate is too low then quality will suffer.