Apple Final Cut Pro 5 - Manual (Page 841)

54 Part I Media and Project Management
0 dB (Analog) Versus 0 dBFS (Digital)
Even though audio is exclusively digital in Final Cut Pro, it is likely that your audio will
exist in an analog context at some point. Even an entirely digital workflow begins
with microphones and ends with speakers, which are both analog devices.
When you look at the meters in Final Cut Pro, you need to consider how the signal
level will correspond to an analog meter. Specifically, you need to choose a point on
the digital meter that corresponds to 0 dB on an analog meter.
This point is where your average signal level should be, providing headroom for
occasional peaks. Headroom is particularly important in digital audio because any
audio that goes beyond 0 dBFS on the digital meter instantly clips and sounds
distorted.
The level you choose for your average audio level affects the potential dynamic range
of your mix. The lower your average signal is allowed to be, the greater the difference
between the average and loudest sounds, providing a larger dynamic range.
There are several common digital levels used to correspond to 0 dB on an
analog meter:
 –12 dBFS: This level is often used for 16-bit audio such as DV audio, and for projects
with compressed dynamic ranges, such as for television or radio.
 –18 or –20 dBFS: This is more common on projects with higher dynamic range,
such as professional postproduction workflows using 20- or 24-bit audio.
What Does 0 dB Mean?
On an analog meter, 0 dB is the optimal recording or output level of a device. If the
voltage is much higher, it may distort. If it is much lower, it may be lost in the noise
inherent in the device. On a digital meter, 0 dBFS refers to the highest audio level
allowed before clipping.