RMS Level for Mastering: Optimizing Audio Through RMS and Plugins

RMS Level for Mastering: Optimizing Audio Through RMS and Plugins

Achieving the perfect loudness can be very challenging for a mastering engineer. Elements such as peak volume, dynamic range, LUFS, and RMS challenge the mastering process. This article will cover the individual and collective relationship between these factors.

What is RMS?

Root mean square or RMS is a tool that measures the average loudness in audio within 300 milliseconds. The average value shows the level of distortion in loud music and how a listener would perceive the audio. In addition, RMS shows the average audio signal value that the mastering engineer needs to control to improve the quality of the music.

Since music sounds different to every ear, RMS alone does not give a very accurate benchmark for loudness. It has to be integrated with LUFS, and the mastering engineer has to make sure that both the tools are not peaking simultaneously. If both RMS and LUFS are within the standard limit, it can be said that a good music mix has been created. RMS shows the average, while LUFS gives a more accurate representation of how the music would sound to an ear.

The Optimum Level of RMS:

Depending on the music and its purpose, adjusting the RMS can be tricky. There is no fixed standard of RMS, and it mainly depends on the music. For example, loud, dynamic, and energetic music should be in -7dBFS to -12dBFS, while calmer and slow music can be in -16dBFS to -18dBFS.

The real challenge is managing the peak audio levels in a mix when different tracks compete for the same space. Level meters are used to ensure that the audio mix is adequately managed. Reducing the distortion is significant in maintaining the perfect mix of RMS levels of different audios at the optimal level.

How is RMS Different from Peak Value?

RMS shows the audio level over a short period, usually 300 milliseconds. Although this snap is very short, still it is a considerable time for the mastering engineers. On the other hand, the Peak Value instantly shows the noise level. Combining the two gives an accurate reading of where the engineer needs to work and how the quality of the music can be improved. The musicians need to utilize both tools to manage the music mix better.

Peaking Mix and the Issues:

We need to understand that loud music is not necessarily good or bad. It depends on the overall mix, and it is the job of the mastering engineer to make sure that the music is pleasurable for the ears. While the musicians want to capture the highest possible notes and pitches, there is a very thin line between pleasure and noise.

The frequency spectrum is a valuable tool as human ears cannot listen to different pitches and levels of sound. Still, when they are combined in the form of music, these different pitches can cause problems for the listeners.

When different sounds are mixed, pitches fighting for the same slot usually cause difficulties for the engineers. As a result, different elements of music are allocated different slots, which eventually become a refined final version without causing distortion and noise. The musician’s discretion also plays a significant role in this peak analysis as everyone has a different taste in music.

It is essential to adjust the dynamic range of each soundtrack using these tools and adequate knowledge of mixing techniques so that the final music does not cause problems for the human ears. The readings of RMS can help in this regard along with LUFH, and the EQ is stabilized and managed to reach a reliable fix in the music.

Range of Frequency and Perception:

The human ears are designed to listen to sound waves between 20 Hz and 20k Hz. Although this may decline over time as aging effects can reduce the hearing capacity of the people, mastering engineers need to understand this concept when developing music. Since the music cannot be adjusted according to every ear, the engineers and musicians plan the frequency on a generic level that is audible and enjoyable for the majority of the people.

A proper balance is needed across the frequency spectrum to make a desirable music mix. Although it is safe to say that the frequency should fall within the range of 20-20k Hz, depending on the audience, the EQ needs to be adjusted. In addition, as people grow older, they cannot hear the extreme ends of the frequency range; thus, an optimum balance is needed to make the music pleasurable.

RMS and Limiters:

Both these tools need to work together to achieve the desired loudness level and remove the possible distortion. The limiter sets the minimum and maximum range of the loudness, and RMS identifies the areas which can be worked on to improve the quality of the music. Limiters can instantly boost the music, so the limiters must be used appropriately.


Different plugins are used by mastering engineers such as BUTE Loudness Analyzer 2, which allows the musicians to manually switch between RMS readings, LUFS, and the True Peak. The interface of this plugin is easy to use, and the user can see the playback logs to optimize the music further.

iZotope Insight 2 is another plugin used by many music composers as its customizable interface allows the users to see multiple screens and optimization levels simultaneously. In addition, RMS and variable LUFS is integrated into the plugin for better monitoring and management of loudness and peaks.

LEVELS is a very easy-to-use and self-explanatory plugin usually recommended for beginners and amateurs. It allows the user to work on six different levels: stereo fields, LRA, bass pace, dynamic range, peak, and LUFS.


The musicians need to understand that the human ear is a complex organ. To make the music meaningful and pleasurable, loudness and frequency have to be managed appropriately. There are a lot of tools available for musicians these days that can help them produce high-quality music. Limiters, RMS and LUFS, should be used by music composers to refine the music to its maximum potential.


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