16bit vs 24bit

16bit vs 24bit

A brief outline of the differences between 16bit and 24bit digital audio in mixing and mastering scenarios.

Written by David Mackie Scouller at Dynamic Mastering Services

Dynamic Range

​Dynamic range is the difference between the loudest possible signal and lowest possible signal before the noise floor is reached.

Digital

16bit = 96dB dynamic range (65,536 possible amplitude levels).
24bit =144dB dynamic range (16,777,216 possible amplitude levels).

Note the correlation between dynamic range and possible amplitude levels.
 
The dynamic range of 16bit is more than adequate for any music genre.

Analogue

Vinyl =  70dB dynamic range.
Reel To Reel Tape = 60dB dynamic range.
Cassette = 50dB to 56dB dynamic range with Metal IV giving the largest dynamic range.
 
In a normal room most people consider 60dB to be silence.

Mixing Stage

Working at 16bit or 24bit the loudest signal peak can not go beyond 0dBFS (zero decibel Full Scale).
 
When at the recording/mixing stage it is best to work at 24bit with plenty of headroom.
 
24bit allows for there to be no concern over a large headroom due to the 144dB of dynamic range.
 
Headroom is the difference in dB from the loudest signal peak and reaching the maximum limit of 0dBFS.
 
When submitting a recording/mix for mastering it is best practice for the recording/mix to have some headroom therefore it is also best practice for the recording/mix to be 24bit.

Mastering Stage

To create a 16bit master from a 24bit recording/mix the least significant 8 bits are removed which can lead to truncation distortion.
 
Truncation is the name given to the process of removing the least significant 8bits.
 
Before the truncation process dither can be applied to eliminate truncation distortion.
 
Dither is a very low level shaped noise which eliminates the distortion caused by bit reduction.
 
Vinyl pre-masters used for making the cut to vinyl ideally require headroom so are therefore delivered at 24bit.

Conclusion

​There is no advantage to having a 24bit master vs a properly dithered 16bit master.
 
The Red Book standard for CD is 16bit and was created as a protocol to deliver high quality digital audio.

Masters that are 24bit are not a widely accepted for distribution with some services refusing to accept them.
 
16bit masters are still the most compatible format today.
 

16bit vs 24bit. A brief outline of the differences between 16bit and 24bit digital audio in mixing and mastering scenarios.