Good Audio, Don't overlook it.
Compared to earlier days of audio cassette recorders, digital recording equipment makes getting quality audio much easier today. However, as good as digital video sound is, there are practical limits. For example, digital audio is unfortunately very easy to overload and distort. Wit the use of analog tape (cassettes), you could go a little past the limit in the measuring equipment and be ok. In the digital world, the limits are more strict. Any volume beyond the limit is heavily distorted. Unlike analog recordings, digital distortion isn't soft or fuzzy but a harsh, nasty sound you don't want in your video. Some camcorders have Automatic Gain Control, or AGC. The problem is you get audio that changes volume automatically, reducing loud sounds or or increasing the volume on soft sounds, sometimes bringing the air-conditioner and other everyday sounds to the same level. If your camcorder has manual audio level controls, it will be important to learn to read and monitor the audio meters during your recording.
Manual audio adjustments let you to get optimum signal into the camera while unfortunately opening the door to possible distortion. If using a mixer, the mic levels should be strong, but not too strong. In connecting the mixer to your camcorder, verify proper audio level by instructing the talent to laugh loudly or speak in their strongest voice. This should be used as your maximum level and DO NOT change it. This procedure should be helpful to end up with consistent, clean audio that is easy to edit for your final production.