Apple Final Cut Express HD - Manual (Page 599)

Chapter 43 Audio Levels, Meters, and Output Channels 599
VIII
If you set the reference level of the Final Cut Express HD floating audio meter to
–20 dBFS, you have nearly 20 dB of headroom, since 0 dBFS is the digital limit for the
loudest sound. If you set the reference level in your sequence to –12 dBFS instead, you
have less headroom. Even though the average level of your audio is higher, there won’t
be as much dynamic range.
How much dynamic range you allow in your audio mix depends on its ultimate
destination. If you’re editing a program for TV broadcast, a reference level of –12 dBFS is
fine, since you are only allowed 6 dB of dynamic range anyway. But if you’re working on
a production to be shown in movie theaters, consider using a reference level closer to
–18 or even –20 dBFS (both of these are frequently used standards).
Remember that the ultimate goal is to ensure that audio doesn’t peak over 0 dBFS in
your mix (as displayed in the Final Cut Express HD audio meters) and won’t peak over
+3 dB or so on an analog meter.
Available headroom with
a reference level of –12 dBFS
- ∞
-66
-36
-24
-18
-12
-6
0
-48
Generic
VU meter
Final Cut Express HD
audio meters
-30
-20
-10
-7
-4
-2
0
+2
+4
+7
6 dB of digital overhead does not equal
6 dB of analog overhead. It’s closer to
3 dB of analog overhead.
- ∞
-66
-36
-24
-18
-12
-6
0
-48