The Proper Way To Measure Loudness

Achieving commercial loudness is an important step in making a great song. Without it, your songs might sound weak and underwhelming compared to the competition.

The first step to achieving commercial loudness in your songs is to measure it. There are many ways to measure loudness. By using the right methods, you can quickly and confidently determine how loud your songs really are.

An Artistic Decision

Loudness is not just a technical specification. It’s also an artistic decision. 

Just like writing a melody or choosing a sample, loudness contributes to a song’s identity.  Some songs will benefit from being louder, like in EDM and rock. Others will benefit from being quieter, like an acoustic ballad. 

There is a wide range of possibilities when it comes to your song’s loudness. Choosing the right level is key.

Measuring Loudness

There are many ways to measure loudness, but some of them are more effective than others. Most DAWs come with stock tools for collecting this data. If you DAW doesn’t, there are plenty of free options available too.

Peak Level is the loudest individual moment of a song. It is measured in decibels relative to full scale (dBFS), which means decibels relative to 0 dB (clipping).

The benefit of measuring peak level is that it determines if distortion occurs at any point (over 0 dB), which should be avoided if possible on your master bus. However, it only measures the loudest peaks, not the overall loudness. 

Your song may have loud peaks, but the rest of it may be relatively quiet.  

True Peak Level is the loudest individual moment in a song with intersample peaking factored in. This measurement is similar to peak level, but it extrapolates the volume of the song between digital samples (what make up a song file) to find the true loudest points, which may be louder than the peak level. 

Simply put, true peak measurements are a more accurate form of peak level measurements.

RMS (Root Mean Square) Level is a measurement that determines an average signal level (measured in decibels) across an entire song. RMS level is a better way to measure loudness than peak or true peak level since it takes into account the entire song and not just the loudest moments.

LUFS (Loudness Units relative to Full Scale) is a specialized measurement of loudness that takes the nature of human hearing into consideration when determining an average volume.  

To reflect the imperfect nature of our ears, certain frequencies are weighted higher or lower when calculating LUFS to get a more accurate loudness measurement. Like the decibel measurements discussed, LUFS is measured relative to 0 Loudness Units (LU).

There are three ways to measure LUFS:

• Momentary: the average signal level over a 400 millisecond period
• Short term: the average signal level over a three second period
• Integrated: the average signal level for a longer duration of time, usually an entire song

LUFS is not a perfect measurement of loudness, but it is a measurement that has become increasingly popular in recent years. Integrated LUFS is the best numerical way to evaluate the loudness of an entire song.

Perceived loudness is how we experience and interpret sound with our ears and our brains. Unlike the previous methods, there is no way to correlate what we hear with a specific number.

Our ears are imperfect and do not work like our digital measurement tools, so measured and perceived loudness do not correspond perfectly with each other. Two songs may have the same numerical loudness, but to our ears, one may sound noticeably louder than the other. The ability to determine relative loudness is still very useful. 

Perceived loudness is the most important measure of loudness because it is exactly how we experience sound. Certain decibel or LUFS measurements may indicate that a song is a certain loudness, but our ears are always the final test. 

How Do Commercially Released Songs Stack Up?

Evaluating your song’s loudness with each of these methods has its pros and cons. The reality is, there isn’t a set of values that will magically help you achieve loudness. Different songs require different levels of loudness.

To test this, I collected a random set of song files (in WAV and MP3 format) to test all of these measurements. I pulled each file into a DAW project, listened to each track individually, and measured them with each method.

To measure perceived loudness, I ranked each song based on how loud each sounded compared to the rest. My ears are by no means perfect at judging loudness, but it was interesting to observe the differences in loudness and to see how my ears performed in comparison to the numerical  measurements. 

Here are the results, in no particular order:

Artist	Track	Year	Genre	Peak (dBFS)	True Peak (dBFS)	RMS (dBFS)	Integrated LUFS	Perceived Rank
Beyonce	Foundation	2016	Pop/Hip Hop	-0.2	0.4	-6.7	-8.9	4
The i.l.y’s	Stop Yelling in The Museum	2016	Noise Rock	0.0	3.0	-7.2	-6.1	1
Dr. Dre	Talk About It	2015	Hip Hop	0.0	1.3	-7.7	-8.2	2
Billy Joel	You May Be Right	1980	Pop Rock	0.0	0.4	-11.9	-12.2	12
SBTRKT	Pharaohs	2011	UK Garage	0.0	1.3	-10.5	-10.8	9
Queens of the Stone Age	I Sat By The Ocean	2013	Alternative Rock	0.0	0.2	-6.7	-6.4	5
Nas	Halftime	1994	Hip Hop	0.0	0.3	-11.3	-11.2	11
Kanye West	On Sight	2013	Industrial Hip Hop	0.0	0.5	-7.5	-7.2	3
Janelle Monae	Givin’ ‘Em What They Love	2013	R&B	0.0	0.3	-9.1	-11.0	10
Haim	The Wire	2013	Pop Rock	0.0	0.3	-6.0	-7.9	7
El-P	Deep Space 9mm	2002	ExperimentalHip Hop	0.0	0.5	-6.2	-9	6
Disclosure	When a Fire Starts To Burn	2013	House	0.0	0.4	-6.3	-8.1	8

Let’s break down the results by measurement:

• The peak level of almost every song was exactly 0 dB, but the true peak level varied from sitting just over 0 dB (minor clipping) to 3 dB (likely intentional clipping). Despite all of these songs clipping to some degree, these technical imperfections never got in the way.
• RMS levels varied from -11.9 dB to -6 dB. These levels only somewhat correlated with the true peak level of each song.
• Integrated LUFS varied quite a bit as well, from -12.2 LUFS to -6.1 LUFS. Notice that not a single track was mastered to -14 LUFS (a common myth), including the oldest song tested, 41 year old “You May Be Right.” 
• My Perceived Loudness rankings were unsurprisingly not aligned with any single measurement, but they did seem to correspond best with LUFS. It was difficult to precisely order every song on the list, but the differences between the loudest songs and quietest songs were obvious. Despite these differences, I found that each track sounded appropriately loud.

As you can see, loudness is not a standard set of numbers to hit. It is a highly variable trait that differs as much as the creative choices of each song.

The Right Way To Evaluate Loudness

Now that you’ve seen some examples, the biggest question remains: how should you measure the loudness of your songs? 

The answer is simple: use a reference track.

By taking a professionally released song with a similar genre and style as your own, you can evaluate how loud your songs are and determine if they need to be louder, quieter, or stay the same.

To compare your song to a reference track, get a file version of it and put it into your DAW next to your song. Listen back and forth to them by muting and soloing the reference track. 

Pay attention to the two track’s relative loudness. Is your song louder than your reference? Quieter? About the same?

If you want to use a numerical measurement, use Integrated LUFS, since it is the closest representation of what you can hear with your ears. How close are these values? They don’t have to be identical. 1 LU or less of separation is a good target.

If your song has louder and quieter sections, use short-term LUFS as well. The loudness of different sections should be considered independently. 

How Loud Are Your Songs?

Loudness is an artistic choice – not a metric to hit and forget about. If you’re not taking control of that choice, there’s a chance your songs might suffer.

With the right tools, it’s easy to determine how loud your songs are. You don’t have makes guesses or wait until they have been released to see what the final results are.

Now that you understand how to evaluate your song’s loudness, do this with some of your finished songs. Are they loud enough?

Want to learn how to make a great song?

• Category: Mastering
• Tag: Loudness