Editing Audio
Once you have all of your video clips in the order that you want for your finished project, you will need to check all of the audio levels. Most of the time you will want a consistent audio level for your entire project.
To change the audio you need to click on the audio editing button in the lower left hand corner of Final Cut Express.

Clicking the audio editing button will bring up pink lines within your two green audio bars. When you roll your cursor over the pink line it will change into a two-sided arrow. You can click and drag the pink bar up and down to change the audio level.

You need to know where your audio levels should be within your project. You should not judge your audio levels within your project by the volume on the television monitor. The television monitor volume levels are not accurate representations of the audio levels within your project. You need to use the audio levels window in Final Cut Express. The audio levels window is next to your tools palette window and has a color gradient from red at the top to yellow in the middle and green at the bottom.

Low levels of audio will peak in the green. High levels of audio will peak in the red. You want the majority of your audio levels to peak right at the end of the green next to -12. If there is a very loud noise in your video, such as a car door slamming, it is OK for that noise to peak higher than -12.

Go ahead and play your video clip and watch the audio levels window. If your audio is peaking above -12 you will need to drag the pink lines in your green audio bars down. When you drag the pink lines there will be a number next to the line. Do not worry about what those numbers mean, you will just use them for reference.
Just experiment with dragging both lines up or down depending on whether you need to raise of lower the audio. The numbers next to both pink lines should be the same for both.