Apple Final Cut Express 4 - Manual (Page 596)

596 Part VIII Audio Mixing
When the number of bits per sample is increased, each sample can more accurately
represent the audio signal.
To avoid rounding errors, you should always use the highest bit depth your equipment
supports. Most digital video devices use 16- or 20-bit audio, so you may be limited to
one of these bit depths. However, professional audio recording devices usually support
24-bit audio, which has become the industry standard.
2-bit 1-bit
16-bit 4-bit
Bit depth When used
32-bit floating point This allows audio calculations, such as fader levels and effects
processing, to be performed at very high resolution with a
minimum of error, which preserves the quality of your digital audio.
24-bit This has become the audio industry standard for most audio
recording formats. Most professional audio interfaces and
computer audio editing systems can record with 24-bit precision.
20-bit Used in some video formats such as Digital Betacam and audio
formats such as ADAT Type II.
16-bit DAT recorders, Tascam DA-88 and ADAT Type I multitracks, and
audio CDs all use16-bit samples. Many digital video formats, such
as DV, use 16-bit audio.
1
8-bit In the past, 8-bit audio was often used for CD-ROM and web video.
Today, 16-bit audio is usually preferred, but available bandwidth
and compatibility with your target user’s system are your chief
considerations when outputting audio for multimedia use.
1 Many consumer DV camcorders allow you to record four audio channels using 12-bit mode, but this is
not recommended for professional work.