What is loudness? Understanding loudness in music and mastering levels

Loudness refers to how we perceive sound and plays a crucial role in determining the amount of sound pressure a source is producing at any moment.

Often, we perceive loudness as the intensity of sound before it becomes distorted, especially in the context of audio mastering. In simpler terms, we can think of loudness as a signal that exists right before it starts to distort and clip.

Loudness can also be defined as the strength of a sound. It ranges from quiet to loud. The way we measure the scale relies on the individual, as it's a subjective process that takes into account the sound intensity, frequency, and duration of both acoustic and electronically reproduced sounds.

When we examine the loudness of a sound, we focus on how loud or soft it appears to someone listening from afar. When the decibel level rises, the sound waves become more intense, making the sounds louder.

What is the process of mastering?

The process of mastering includes

• Adding the final polish to the mix of the song

• Making sure that the sound is consistently perfect in any device, in a standard phone speaker, or in a big live sound system

• Balancing the sonic elements of the mix

So the process of mastering is the final stage in the creative process of music production. There is a lot of extra magic that unfolds, and that draws the listener closer to your music and creates a deeper sense of connection. In short, it can enhance the core reason you created this music in the beginning. It’s better to understand how you can prepare your music for the master format. When you know how, you’ll add an extra layer of magic to your creation.

Furthermore, the music listeners, industry professionals, and mastering engineers often see audio mastering as the work of one expert who fine-tunes, polishes, and fixes a set of recordings that are considered ready for release. We, as the mastering engineers, are responsible for preparing the metadata, arranging the sequence on the album, and adjusting the relative volume before distributing it in various formats.

Why is loudness an important factor in mastering?

There are some factors to consider when we dive deeper into the mastering process. Loudness is truly one of the important factors. It definitely makes the track feel more powerful and gives you a competitive edge when you play it alongside other, quieter songs. However, how can you dial in a loud master without losing the pure quality of your sound?

Metrics of loudness

Before we see how, now let’s explore the metrics of loudness and take a look at LUFS vs. RMS.

LUFS (Loudness Units Full Scale)

We can measure how loud the sound is perceived when we consider how our ears respond to different frequencies, thanks to LUFS. It helps us to maintain consistent loudness across various tracks and platforms.

Where is LUFS used?

Streaming services and broadcasting use LUFS levels to ensure a consistent listening experience.

We can understand a clearer picture of how loud something sounds through LUFS, so we don’t only just look at peak levels.

It’s important to meet the loudness standards. These are set by streaming platforms like Spotify and Apple Music. So it makes LUFS an important metric for loudness.

RMS (Root Mean Square)

When it comes to the other metric of loudness, RMS, it calculates the average power of an audio signal over time. The loudness normalization standard changes based on the criteria for each streaming service. 

RMS offers an important advantage, ensuring every part of the track maintains a balanced volume. So nothing sounds too loud or too soft. RMS becomes a tool for comparing the loudness of various sections in a track.

What does mastered mean in music?

Mastering engineers use the key processes taking place after tracking and mixing to bring the consistent sounds of mainstream and commercial music to life.

If we go back in time to the latter half of the 20th century, we can realize that engineers began to see timbral consistencies as more relevant to their creative choices. Those were especially when using specific combinations of digital software and analog hardware signal processing tools. 

From the history of mastering to today’s world, every practitioner follows a different path and takes a different creative approach. Each piece of processing equipment has its own contribution to the music, adding a distinct coloration to a recording. And this depends on many aspects, including the electronic circuit design, the components used, and how the electrical load is distributed among the devices.

Understanding Loudness Range in Mastering

Now, let’s talk about the Loudness Range (LR). What it does is that it describes how much the loudness changes over time. Through the Loudness Range, we can understand how loudness varies over a larger timescale, as measured in LU, dB scale.

Now we can also try to understand the Consistency descriptor, another essential term that is useful for understanding loudness in music. We can define consistency as the negative half of the estimated Loudness Range. In other words, it’s possible to say that they are equivalent.

You can measure Loudness Range based on the statistical distribution of loudness measurements. This way you can find a good balance between precision and robustness. If a brief but intense event occurs that won’t impact the Loudness Range of a longer segment. Likewise, the measured Loudness Range won’t significantly increase because of the fade-out at the end of a music track.

Why is LUFS the standard for streaming platforms?

As we’ve explained earlier in this article, LUFS, meaning Loudness Units relative to Full Scale, combines how we perceive sound with the intensity of electrical signals. It also helps set targets for normalizing audio in broadcast systems or music streaming platforms. 

Let’s discover the loudness targets set for streaming platforms:

Platform	Peak	Loudness
Spotify	-2.0 dBTP	-14 LUFS
YouTube	-1.0 dBTP	-13 to -15 LUFS
Deezer	-1.0 dBTP	-14 to -16 LUFS
Tidal	-0.1 dBTP	-14 LUFS

The difference between dB and LUFS

dB measures the peak value of a signal. On the other hand, LUFS measures the average volume we perceive.

Audio Mastering Levels and Dynamic Range

Mastering dynamic range and why it matters

Dynamic range is described as the difference between the loudest and softest parts of a track in audio mastering. It is measured in decibels (dB). 

While discovering further, let’s take a look at a wider and a narrower dynamic range.

A wider dynamic range enables more contrast between these extremes and adds depth and emotional impact to the music.

A narrower dynamic range, on the other hand, can make a track sound more uniform and less engaging.

It’s essential to keep the right dynamic range during mastering. Since it influences how the listeners feel the energy and emotion in music. Over-compression might narrow the dynamic range too much while causing a loss of clarity and making the track sound lifeless. Nevertheless, if you want to make the track more expressive and keep the listener engaged, you may preserve transients and allow for dynamic variation.

The role of L and R mastering

In audio mastering, we aim to balance the left (L) and right (R) channels for creating a cohesive and immersive stereo image. Otherwise, an imbalance might make the mix favor one side. That may result in an uneven listening experience.

Therefore, keeping vocals, bass, and kick and snare at the center helps maintain balance while also evenly distributing panned instruments.

Best Loudness Metering Plugins for Mastering

There are various loudness plugins that may help enhance the quality of your master. Let’s see some of them below:

Youlean Loudness Meter

This one is a free plugin letting you make precise loudness measurements. It makes it easier to prepare your audio for different platforms. Youlean Loudness Meter also provides a thorough analysis to meet broadcasting standards.

iZotope Insight

iZotope Insight helps you make informed mastering decisions. It is a popular plugin that’s a complete metering suite providing real-time visual monitoring of loudness, frequency content, and stereo width.

Nugen Audio VisLM

Using this plugin makes it possible to provide accurate loudness metering along with history and logging features. Nugem Audio VisLM helps you ensure your audio meets industry standards.

MeterPlugs Loudness Penalty

MeterPlugs Loudness Penalty is a plugin letting you see how streaming services will adjust your music. You can fine-tune loudness and keep the quality intact.

Characteristics of a Good Mastering DAW

You can evaluate DAWs for mastering. Here are some of the features you can keep in mind:

The DAW needs to handle high-resolution audio (at least 24-bit/96kHz). The goal is to maintain sound quality during processing.

A range of metering methods, including peak, RMS, LUFS, phase correlation, and spectrum analyzers, are required for precise monitoring. Support for industry-standard plugin formats such as VST, AU, and AAX allows for easy integration of high-quality mastering tools, including EQs, compressors, and limiters.

A straightforward interface with adjustable layouts improves productivity and allows you to focus on the most important areas of mastering.

You have control over your audio thanks to precise editing features. With detailed waveform editing, automation, and clip gain adjustments, you can carefully control every nuance.

You may quickly export in several file formats and bit depths, ensuring that everything matches distribution requirements. 

5 Common Loudness Mistakes in Mastering

Mastering can be a tricky and challenging process. Even the experienced mastering engineers can sometimes stumble along the way. We’ve gathered some of the common mistakes to avoid during mastering:

Overly Loud Masters

Even though it might be tempting to crank up the volume, it can still squash dynamics and introduce distortion. Therefore, it is better to remember that streaming platforms often normalize loudness. So the super loud masters might get turned down.

Aggressive Processing

Using too much of any effect can harm your mix. Subtlety is key. If you find yourself making drastic changes, consider revisiting the mix instead.

Ignoring the Artist's Vision

It’s extremely important for a mastering engineer to respect the intentions of the mixing engineer and artist. You need to enhance their work and be careful if you’re imposing your own preferences.

Excessive Stereo Width

It’s better to be careful not to create a too wide master since it can create playback issues on certain systems, especially mono systems. To avoid this, you may keep low frequencies centered and use subtle widening techniques.

Unnecessary Compression

Many mixes you receive to work on the master arrive already compressed. If you add more, it can lead to a lifeless sound. So it’s advised to assess whether you need to add additional compression. 

We’ve talked about the top 5 mistakes you may encounter while mastering a track. There might be more, like improper gain staging or wrong genre references. As a mastering engineer, trying to embrace the whole aspect and look afar might help you avoid the mistakes and reach a good result with your mastering.

Conclusion

Throughout the article, we shared some of the important aspects of music to understand loudness. From LUFS to RMS, we’ve mentioned a couple of different terms and shared some insights into mastering audio.