Editing Signal-to-noise ratio (section)

===Floating point===
[[Floating-point numbers]] provide a way to trade off signal-to-noise ratio for an increase in dynamic range. For n-bit floating-point numbers, with n-m bits in the [[logarithm|mantissa]] and m bits in the [[exponent]]:
:<math>
\mathrm{DR_{dB}} = 6.02 \cdot 2^m
</math>

:<math>
\mathrm{SNR_{dB}} = 6.02 \cdot (n-m)
</math>

The dynamic range is much larger than fixed-point but at a cost of a worse signal-to-noise ratio. This makes floating-point preferable in situations where the dynamic range is large or unpredictable. Fixed-point's simpler implementations can be used with no signal quality disadvantage in systems where dynamic range is less than 6.02m. The very large dynamic range of floating-point can be a disadvantage, since it requires more forethought in designing algorithms.<ref name="rane fixed vs floating">[https://web.archive.org/web/20060515074349/http://www.rane.com/note153.html Fixed-Point vs. Floating-Point DSP for Superior Audio] — [[Rane Corporation]] technical library</ref><ref group="note">Often special filters are used to weight the noise: DIN-A, DIN-B, DIN-C, DIN-D, CCIR-601; for video, special filters such as [[comb filter]]s may be used.</ref><ref group="note">Maximum possible full scale signal can be charged as peak-to-peak or as RMS. Audio uses RMS, Video P-P, which gave +9 dB more SNR for video.</ref>