The unknowable black art of mastering
KeithHandy posted in Coding, Producing on December 9th, 2006
I don’t think mastering is really as subjective as people say it is.
I think it’s about providing a balanced spectrum to the ear, so that you can take a lot in without being fatigued. Having a poorly-mastered recording is akin to having a lot of potholes in the parking lot at an art gallery; the paintings are still intact, but you will enjoy them less because you’re worried about your car.
The ear adjusts to imbalances, or at least the brain does, so if you have a recording that’s bottom heavy, it can figure out that it needs to shift its attention to a weaker part of the spectrum. But this is work for the brain to do, and you’re putting more strain on yourself for no aesthetic advantage. If a listener is going to make any adjustments at all, consciously or otherwise, wouldn’t you rather they go from more strained to less strained as their mp3 player’s random shuffle leads them from someone else’s song into yours?
The visual equivalent of mastering is adjusting the brightness and contrast of a picture. I think there is rarely any advantage to not using the full black-to-white range — if you want it to be a “dark” picture, then yes, have larger dark areas overall, but at least one tiny area should hit full-on white (and vice versa for bright pictures). Gamma and similar adjustments are great for all the stuff in the middle, but there need to be points of reference at both of the extremes.
This brings my analogy back to mastering, sort of. What is the equivalent of “gamma” in mastering? Well, where in pictures we have colors (red, green, and blue being the primaries), in sound we have frequencies from low to high. (Think of frequency not as a simple tone, but as a thin slice of music that “rings” at that pitch.) For any given frequency, we really want it at some point to be loud and at some point to be quiet. To have a continuous full-volume tone at some pitch for the entire duration of a song would be torture. But to never have much energy in that part of the spectrum would leave the sound “hollowed out”, like there was a hole in it. So at any frequency you need to have things happening; you need to have a range of louds and quiets. “Audio gamma” would be how much or how little of the medium-volume sound is closer to full volume and how much is closer to silence. The maximum volume (for that frequency) isn’t really an aesthetic choice, it can be “loud enough to get your attention without hurting you”. The aesthetic choice is how much of the time to spend closer to that maximum.
As I go along, I’ll be using existing music as a model, to automatically adjust the overall sound of my own. Stay tuned!
