Volume Matching, and Evaluating Your Master Recording
Here’s an in-depth article on why volume matching is a great way to more accurately evaluate your master recordings, and how to do this at home.
Before we begin, please note: any mastering engineer should always make your masters as loud or as soft as you would like them. If you’d like to hear something louder, just ask! It’s your music and your call, always.
But, they should also be telling you when it could be getting to a point where higher levels of loudness might not be in your best interest for best sound on a given playback medium, so you can make an informed choice on what loudness level is right for you. With that, here’s some more details on how loudness and volume matching works.
Fundamentals of Loudness and Hearing
Human hearing is incredibly sensitive, and is fully integrated with the rest of our bodily systems. If you’ve ever heard a very loud and very sharp sound, such as a gunshot, you might notice that it can immediately invoke a quite drastic and automatic response, usually one or more of the following:
Reflexively looking for the source of the sound
Eyes widening
A sharp and quick inhale
Muscle tension, jumping, or reflexively crouching
Heart rate increasing
Immediate feelings of apprehension or fear
These responses are evolutionary, and are designed to keep us alive in the wild where dangerous predators could kill us. They are still with us today, even though being hunted by a saber toothed tiger isn’t really an issue anymore.
A similar set of automatic responses takes place when we’re listening to music: the louder the music gets, the more our heart rate increases, and the greater feelings of excitement we sometimes experience. This is probably a good thing (in moderation) at a live concert, but it can be a real problem when evaluating a master recording given to you by your mastering engineer. That’s because these automatic excitement responses mean it’s always easy to confuse a louder sound with a better sound.
Loudness and Hearing Complications
Complicating things, human hearing is not linear. This means that your hearing sense changes, depending on the volume you’re listening at. The louder something sounds, the more it will appear to you to be thicker, bassier, and punchier. Since these are often desirable traits in certain styles of music, this once again means it’s easier to confuse a louder sound with a better sound. This is also the reason why I suggest checking your masters at both loud and soft volumes.
Loudness and Playback Medium Complications
Complicating things even further, different music playback mediums (streaming, vinyl, tape, CD, etc) all have different ideal loudness levels, i.e. levels at which the playback medium will show your music at its best. Streaming platforms in particular favor more dynamic music, which is a good thing. But, this also means that if you choose a master that is too loud, it can actually sound worse when played back through a streaming service. It’s very counter-intuitive, but you really don’t need to worry about your music appearing too soft on modern streaming services, even if a master delivered from one engineer is a little bit softer than another. Here’s why.
Loudness Normalization and Music Streaming Services
Most streaming services have algorithms on the backend that adjust the overall loudness of your music upon submission, to match a general loudness level. This is called loudness normalization, and it’s used by most (but not all) of the major streaming music platforms. Loudness normalization is really great: it’s the tech that allows you to play a jazz track recorded to tape in the 1950s right next to a modern track recorded digitally that’s much louder, and not hear an annoying volume jump when switching between the two.
But, the use of loudness normalization means that if you submit a really loud master to a streaming service, the streamer will just turn that volume right back down in submission processing. It’s not something optional, the streamer will just do it.
In doing so, this process will introduce distortions and artifacts that will make your music sound thinner, tinnier, squashed, less thick, and less punchy. This is probably exactly the opposite of what you were going for in trying to submit your master super loud, right?
Getting tired of thinking about all of this yet? Well, that’s why mastering engineers like myself have jobs. We’re experts on this kind of thing, and we specialize in helping put the finishes touches on your music to make sure it sounds amazing everywhere. You can check out my audio portfolio right here.
Challenges in Master Evaluation
It isn’t uncommon for a musician to approve a very loud sounding master, only to be surprised when it doesn’t sound nearly as good as they remember, after it’s released on a streaming service. This isn’t the fault of the streaming service necessarily, but it could be the fault of a mastering engineer who might not fully understand how modern streaming services work. Or, who doesn’t communicate exactly how these services work to their clients effectively.
This is a particularly challenging line to walk for the mastering engineer in styles of music that are intentionally meant to be experienced quite loud, such as metal, grindcore, etc. When in doubt, just talk to your mastering engineer, and ask how they approach the issue of loudness normalization on streaming services. They should be able to give you a convincing and well thought out response! If not, you might consider hiring someone else.
Solutions for accurate master evaluation
Mastering engineers compensate for all these different loudness effects by using volume matching at all points during the audio mastering process. However, it’s something equally important for the artist to consider as well when evaluating your masters, because you’re the one who has the final call on approval of them. You want your own evaluation of your work to be accurate, not biased by something appearing louder or softer. Remember, louder does not always equal better.
Volume matching means making sure that different audio is being played back at the same apparent volume when making any direct A/B comparison. This will prevent you from confusing louder with better.
If you’re comparing masters sent from different mastering engineers, they will sometimes be slightly different in apparent volume upon delivery. That’s ok, just be sure when comparing each master, that each version is being played back at the same apparent volume when comparing.
If one of the masters you get is a bit softer than the other, just turn it up a little to match the volume of the louder one, before you make a quality evaluation. Or, vice versa: if one master is louder than another, turn that loud one down a bit to match the other, before you make decisions about quality.
You can do this by ear and by simply working the volume knob during playback. Just get it sounding close, no need to get too fancy here. This is a simple step, but I think you’ll be surprised at how much of a difference it makes in making your master evaluations faster and more accurate.
Volume Matching When Mixing and Recording Your Music
You can also use volume matching when mixing or recording your music. Next time you get super excited about slamming the knobs on that compressor (or any other tool that impacts how loud something appears), try volume matching the input and output gain on the compressor by ear, and set your makeup gain to zero, before messing with things like threshold, attack, and ratio.
Taking this step will clearly tell you when you’ve compressed material in a positive way versus taking it too far. You are the final judge as to what “cool compression” and “too much compression” means for your music.
If you’re interested in learning more about this kind of thing, there is an entire field of study called psychoacoustics which deals with how our brains interpret sound, and how that connects with the physics of sound in the natural world.
And, for more information on mixing your music at home, I’ve laid out all the steps to a great mix in order for you in my mixing cheat sheet. Enjoy!
