Fixing Problem Frequencies in Audio Mastering

All musical instruments’ frequency ranges overlap. There is a fantastic chart which illustrates how different instrument’s ranges span across different areas of the frequency spectrum available to buy on Bob Katz website – Digital Domain.

The mix is usually made up of quite a number of different elements, each spanning its own individual group of frequencies. Not surprisingly, almost all these frequencies cross the midrange areas, even the kick drum can go right up into the high mids.

When you consider the reverbs, delays and any other FX, you can appreciate that the midrange can become quite busy, which is one of the reasons why it is so important that good definition has been created here during the mixing stages.

The busyness of the midrange areas can contribute to an uneven build-up of layered sounds across the spectrum. Where there is a lot happening may cause an audible lift in a certain area, or it may sound like resonance. These areas, or specific frequencies can be problematic and can be known as problem frequencies. Where there is little happening, you may find a dip, or a ‘hole’. Even the instruments themselves are not likely to produce each frequency at the same volume, or there would be little expression in the way the musician plays. You can start to understand why the whole spectrum can end up being a little un-even when we get to the mastering stages.

We know that good translation to the consumer’s hi-fi and environment has the best chance with a relatively even spread across the spectrum, but our goal isn’t just to level it out like a bulldozer levelling an old garage. We have to have a clear view of both the music, and the artists’ intentions. The real art of EQ is very much being able to define the intentions of the music. Then make an informed decision, whilst being aware of the limitations, variations and imperfections of the consumer’s player and environment. The track could be rich with varying tones and changing levels, expressing beautifully the feelings of the musicians. Levelling it all out might be damaging to the expressive nature of the track. On the other hand, what would be the point of playing the track if it can’t be enjoyed, or even heard down to the challenging elements of the consumer’s player and environment? We don’t all sit in a quiet, neutral room and listen to music on good quality speakers like we do when we are recording, mixing and audio mastering.

Audio Mastering EQ Technique

That aside, I am going to show you a little mastering EQ technique on how to obtain a more even frequency spread across the spectrum when mastering audio. This will help you distinguish the problematic areas. I’ll also share with you a little tip in deciding whether these problem frequencies should be reduced, or not, or by how much. This technique is very simple, anyone can do it. Although how easily you find it will depend a great deal on the functionality of your EQ.

Below you will find a downloadable piece of music that is in need of some EQ, and on the next page is a step by step video of the technique. Having watched the video, try the technique using the downloadable track. In a short while you will arrive at another video which demonstrates this mastering technique using the downloadable piece of music, revealing where the adjustments needed to go.

Download track here… Maria Sins-Changes.wav

Next Page… Linear Phase EQ Mastering Technique