Guides on Audio EQ and Compression

Here are some good guides to the concepts and practice for EQ and compression:
"Basic Guide to Understanding EQ"
"Taming Your Audio Signal with Compression"

I've always thought of myself as a visually-attuned person, but much less sensitive to sound. So while I think I have a natural proclivity to catching things with my eye, I think I have to work much harder for sound--I think I learned much quicker what looked right and how to make it that way than I was to learn when something sounded right and how to make it so.

After level changes, the next basic tool in your audio kit is EQ. Back in the day, when someone told you that she or he wanted to make something sound better in the edit room, you were going to turn to the EQ. I've done a fair amount of linear editing, and that meant using the EQ knobs on your mixer. I still turn to the mixer from time to time. It's a quick way to check out how adjusting different frequencies will affect your audio. The Mackie VLZ mixer, which most of our editors have, has low-end, mid-range, and high-end adjustments. If may not really improve the track, but it's a quick way to check if you can make something sound better by raising or lowering the level of particular frequencies (just remember to turn those pots back to unity when you're done testing--so you don't screw up someone else's audio.) Then once I've found a setting that I like, I'll recreate it with an EQ filter in Final Cut. The B&H article Basic Guide to Understanding EQ describes different kinds of EQ beyond what you'll find on your basic mixer. Shelving and cutting are also available in Final Cut Pro as filters.

Nowadays I usually find myself turning to compression first when I want to help an audio track--especially a clean track, like one recorded in a VO booth or a quiet studio. I'm pretty conservative on compression. I think it's overused on a lot of TV and radio, especially when annoying white guys are yelling to be the loudest person in the world. But even in milder forms, it can give a voice some punch. So for example, this article Taming Your Audio Signal with Compression recommends compression ratios of 2 to 4, whereas I usually keep my ratio at below 2. BTW, a ratio of 1 does nothing. Of course, this is the default setting, so if you're not familiar with compression then the first time you use it, you might think it does nothing.

Final Cut Pro does compression, but Soundtrack Pro's multipressor effect is even more powerful. I use multipressor to have a little noise gate in the effect, and I like the graph display so I can the audio levels where the noise gate is working and where the compressor is working. If I have the time then I'll often take a track to Soundtrack Pro. If it's shot in our studio, then I'll want to do some noise reduction first, then I'll do a multipressor, and then I'll apply the limiter in Soundtrack Pro. Soundtrack Pro's limiter works much better than FCP's. I like how you can see how much the limiter is working in the filter settings window. The limiter works similarly, but more crudely, than the compressor in that it can be used to give your track more punch.

I found these articles over at FreshDV. These articles are part of the B&H Pro Audio Newsletter, which you can subscribe to on their homepage. Most of what I have learned about audio I learned from the writings of a guy called Jay Rose . I keep a copy of his "Audio for Post Production" around the office, which I recommend for both beginners and experienced editors who want to dig deep into sound issues.