Instruction Manual

547
Advanced Audio Processing
Editing Audio
To Remove DC Offset From Existing Audio
1. Select the audio data and choose Process-Audio-Remove DC Offset.
This launches the Remove DC Offset dialog.
2. Choose from the following options, and click OK:
• DC Offset Threshold (dB)—you can set a minimum dB threshold. If
the analyzed DC offset is below this value, no removal takes place.
• Analyze Left Channel (dB) and Right Channel (dB)—this field
displays the DC offset separately for the left and right channels.
Press the Audition button to update the display.
• Compute DC Offset from first 5 seconds only—to speed
processing, select the Compute DC offset from first 5 seconds only
checkbox. Only the first five seconds of a sound file will be
analyzed when measuring the DC offset. The only time that five
seconds is not sufficient is if a long fade-in or mute has been
applied at the beginning of the file.
To Remove DC Offset During Recording
1. Use the Process-Audio-Remove DC Offset command to open the
Remove DC Offset dialog.
2. In the DC Offset Threshold (dB) field, set a minimum dB threshold, and
click OK to close the dialog. If the analyzed DC offset is below this
value, no removal takes place.
3. Open the Audio Options dialog (Options-Audio command), and on the
Advanced tab, enable the Remove DC Offset During Recording
checkbox, and click OK.
This option filters out DC Offset according to the threshold value that you
set in the Remove DC Offset dialog.
Applying Fades and Crossfades Offline
SONAR provides several commands for applying gradual volume changes
to audio data. The first command, Fade/Envelope, lets you fade-in or fade-
out, and lets you choose an envelope, a curve that governs the rate of the
fade. The starting envelope can be linear (straight line), exponential, or
inverse exponential. You can change the shape of the envelope before
applying the fade.
The envelope in the Fade/Envelope dialog box is made of one or more
connected line segments (the linear curves are a single segment, the
exponential curves consist of nine segments each). Although the endpoints