.APPENDIX


References

The Digital Domain website, http://www.digido.com, contains further references to topics mentioned in this booklet, with information on dither, compression, metering, monitor calibration, "good-sounding" commercial CDs to listen to, scientific references, and more..


dBFS - dB reference full scale

Full scale digital is defined as 0 dBFS, the maximum numeric levy which can be encoded.


Gain, Loudness, Volume and Level

Loudness is the subjective judgment of level, by ear. Loudness is an approximate quantity, while level can be repeatable measured, if the averaging time of the measuring instrument is specified. In a professional context, don't use the term volume to avoid confusion with quarts and liters - use loudness instead. Use the professional term gain control rather than volume control. Gain is often confused with Level. Gain is the property of an amplifier or attenuator, while level refers to the amount of signal going through that amplifier. For example, a signal may measure a level of -10 dBFS before going through an amplifier. If the amplifier has a gain of 6 dB, then the level of the signal on the output of the amplifier will be -4 dBFS. Absolute values are applied to level (e.g., 6 volts, or -12 dBFS), while only relative values can be used for gain (e.g. a gain of 2X, or +6 dB). It is incorrect to say that a device has a gain of +7 dBm or dBv... dBm or dBy or dBFS are absolute terms reserved for measured level not for gain.


Sample Rate

The number of samples per second. The preferred abbreviation is S/s, or kS/s, e.g., 44.1 kS/s. Common usage is "44.1 kHz", but this approach is often confusing when the same sentence also refers to bandwidth or frequencies of interest.


ACKNOWLEDGMENTS

A big thank you to Bob Ludwig, of Gateway Mastering, Portland Maine, and Glenn Meadows, of Masterfonics, Nashville, Tennessee. Bob and Glenn reviewed the manuscript and added helpful suggestions that made an even better booklet.


Quelle: Bob Katz