Here are a few simple, non-technical techniques to go through to help maintain audio level balancing while video editing.
Audio balance is an important part of the post-production video editing process. For video to become engaging and surpass itself as simply a technical exercise, it is important to take control of the entire media package. This means making sure that different audio spots that are supposed to remain the same are; and that other competing ones are layered. This can be difficult since each piece of audio was recorded slightly different due to varying conditions. Here are a few tips for balancing your audio tracks once you get into your non-linear video editing software.
The best way to do this is to look at the intensity of audio levels of each individual clips. Take one audio track if you are attempting to match an equal track and look at the audio levels and mark a base point for its highs and lows. Then look at the next clip and see if it matches. If it does not you can adjust your audio levels to compensate.
If you are trying to stagger audio levels as you might with sound effects and a soundtrack then you are going to have a much more difficult of time. Here you really are going to have to use trial and error when listening. The big part here, especially with outside music, is that you are going to have to change the levels over the course of the audio clip. Your primary audio will change intensity, as will the song, so you have to go through and use Timeline markers to indicate these highs and lows. Make sure your Timeline markers are correctly labeled. From there you can move the audio levels up and down for your secondary track, and occasionally for the primary.
You want to make sure that the overall audio of a sequence segment is not over cluttered or loud. It is better to lower the levels of each track individually, yet if you like the clarity you can then reduce the overall sound of the final out put. You are not going to know for sure what everything sounds like until you export, compress, and transfer to the final, intended distribution format. This is especially true of DVD and Blu-Ray disc authoring.