The Importance of Headroom: A Before and After Example of Mastering Audio

I often get emails from new clients who ask what levels I prefer mixes to be at prior to mastering and my answer is somewhat the same all the time. It’s all about making the mix sound good to you first; getting the feel of all the elements of the mix sounding right to your ears while keeping enough headroom so that when it comes to mastering the mix (for the sake of translation to all systems) you’ll have plenty of room to explore different options when you decide to maximize the output later on, whether you are doing it yourself or will have someone else master it for you. This article will give you an example of what I consider an optimal mix ready for mastering, and then what I was able to do with it, which I consider an optimal master (see small rant at the end of this article). Shout out to Melbourne’s Saki for letting me use one of the cuts from his upcoming EP, “The Silent Son” which I mastered recently. The track we are using is “Sounds Around Us”, Produced and Mixed by Arkiv.

As you know, sonic decisions are best made by listening, but that doesn’t mean that visual tools are useless. When looking at the before and after waveform shots, focus on the black areas – that’s headroom. When looking at the differences between the original mix and then the master, notice how much of that headroom has been used, but how you can still “see” some of it between the red parts (which is signal). A lot of that is “crest”, or Peak-to-Average Ratio that you can actually see. Often times I see heavily maximized masters that look similar to a solid brick when looking at it in Waveform view and that means very little crest factor.

Saki – Sounds Around Us
Produced and Mixed by Arkiv

Before (original mix)

Peak (max): -1.69dB
Average RMS: -18.65dB
Max RMS: -9.32dB

After (mastered)

Peak (max): -0.9dB
Average RMS: -13.72dB
Max RMS: -5.06dB

Leaving a little bit of headroom even after mastering is important for hip hop releases. There are tons of rich transients in the lower, lower mid and middle frequencies that are too often squashed because people think their album should compete in loudness to everything else out there, killing what a lot of people perceive as “warmth”. I hope that when listening to the above master, you noticed the subtle overtones from some of the background instruments, and how the sax towards the end is able to breathe and sound smooth while there’s plenty of punch on the output.

A lot of the hip hop records I consider classic (from both east and west coast artists) from the late 80’s and 90’s have similar loudness levels to this example (many even lower). If you crank the volume on your system while playing some of those classics, you can see how much the drivers are working back & forth (more crest, bigger distances between the positive & negative signals) which, if you listen to on a nice full range system, results in a helluva lot more punch than records that are maximized too much and don’t have anywhere near the same amount of crest that cuts like the above have when you turn up the volume a few dBs to “catch up” to the loudness of the heavier-maximized record. Props to Saki and Arkiv for realizing the importance of levels. Thankfully, I’m seeing a bit more clients with similar levels in their source mixes but there are still a lot of artists, producers and engineers who need to perhaps realize how important it is to have headroom in their projects.

You can read more on what I think about loudness and how to improve your mixes by reading part five of my series on mastering at:
http://www.redsecta.com/pdf/RedsectaMasteringSeriesPartV.pdf

For more on Saki, check: sakiaus.bandcamp.com, @SAKI66 on Twitter
For more on Arkiv, check: soundcloud.com/arkiv, arkiv.bandcamp.com, @_Arkiv on Twitter