[This article was first published in the November, 2010, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe.]
L. Blake Baldwin asks two audio questions:
1. Why does the Master Gain default to .51 in Final Cut’s File > Log and Capture > Settings tab? Is that the proper setting?
2. Under what circumstances do you use a +3 dB audio transition instead of a 0 dB audio transition?
Larry replies: Blake, good questions.
About your first question, on my system, Master Gain defaults to 1.0. The 0.51 value does not strike me as a correct setting. This could be caused by accidentally changing the master gain in the audio mixer (Tools > Audio Mixer), or corrupted preference files. Trashing your Final Cut Pro preferences should reset this setting to the correct value.
Regarding your second question, audio gain is not linear, it’s logarithmic. This means that when you do a straight linear fade between two audio clips, there will be a slight fade — of about 3 dB in the middle of the transition. This linear fade is called an “equal power” transition. (I’ve illustrated it below using a screen shot from Soundtrack Pro, which shows the shapes of the two fades that Final Cut Pro supports.)
To fix that audio dip during the transition, we can add 3 dB of gain to the middle of the effect, thus canceling out the audio dip. This logarithmic fade is called an “equal gain” transition.
In general, use the 0 dB transition when fading to or from black. Use the +3 dB transition when fading between two audio clips. The +3 dB fade is the default setting for Final Cut.