Are You Listening? S2 Ep. 3 | Loudness Metering and Visualisations in Mastering

Are You Listening? S2 Ep. 3 | Loudness Metering and Visualisations in Mastering

Matthew Vere
Matthew Vere

Table of Contents

Mastering With Your Eyes

Meters help us confirm or validate what we’re hearing. Sometimes they may show us things that are right at the edges of our hearing.

Loudness Meters Explained

Peak Level = Instantaneous measurement of peak amplitude using a concise time interval.

Our brains don’t evaluate pitch, or loudness according to instantaneous measurements. Our brains need a little longer to understand what the sound is that we’re hearing.

RMS =  Root Mean Square meters display the average level calculated over a short window of time (around 300ms). This more closely matches the way our brains work, as it’s the window of time we need to evaluate loudness.

If you’re thinking about how loud your song is when compared to every other song in the universe, the RMS is the level you’re interested in.

Oasis — (What’s the Story) Morning Glory — One of the loudest records ever made (-5 RMS — little to no crest factor)

Beyoncé — Partition (Wide peak to average relationship/crest factor)

LUFS/LKFS Explained

LUFS/LKFS = Interchangeable

LUFS = Loudness Units to Full Scale — a measurement of perceived loudness by analysing the average level over time.

LUFS takes the idea of the RMS measurement and brings forth the concept that our ears/brains are not equally sensitive across the spectrum. If you take 1 kHz tone and play it back at -20 dBFS and then a 50Hz tone and play it back at the same level on the meter, the 1kHz tone will sound louder by somewhere in the magnitude of 10 — 12dB. LUFS metering reflects our perception of sound across the frequency spectrum.

If you’re always mixing to the same level yet some tracks sound louder, it may be to do with one mix having more low end than another.

LUFS isn’t the perfect system for evaluating level from a technical perspective, but it is an excellent way of evaluating level according to how we perceive sound.

There are three kinds of LUFS measurements:

Short term is an average measurement that takes place over 3 seconds.
Momentary is an average measurement that takes place in less than 3 seconds.

Integrated measurement history:

Have you ever noticed while watching TV that adverts can be much louder than the program you’re watching? This can be jarring and is a ploy by advertisers to grab your attention. The loudness discrepancy became such a problem that the US and EU passed laws to prevent this from happening. Thus, the integrated loudness measurement was born. Now, the level across a whole program and any advertisements must accord to a particular level.

US Standard for Broadcast associated with video = -23 LUFS
EU Standard for Broadcast associated with video = -24 LUFS

Most streaming services now implement this idea of measuring the integrated loudness across a track and conforming the level to their playback standards.

Don’t mix/master to a target, mix/master to where the music sounds and feels good. Ensure you have the right amount of contrast from one section to another, a chorus should be louder than a verse, for example.

Adjusting Levels According to a Meter

Johnathan’s mainly looking at the peak to average ratio (crest factor), as he wants to understand how much headroom he has. He’ll pay attention to the average level and ask: if the track needs pushing, by how much? If the average isn’t high enough, you might experiment with a limiter. If you need to apply more limiting than would be ideal, it’s worth looking at what you can do downstream to alleviate that.

Other Important Visualisations for Mastering

A crest factor meter is a helpful tool for monitoring the relationship between the kick drum and bass. If a kick drum rises high in the low-end, it will eat up a lot of headroom on the master, and make it challenging for you to hear the bass.  If the opposite occurs and the kick drum becomes buried beneath the bass, then you lose that sense of drive from the low-end transients.

If the crest factor is high, showing a track is dynamic, this may give you cause to pull back that kick drum in the low end.

Viewing the track in RX can give you an accurate picture of what’s happening in the low end. RX can also reveal noise issues like clicks and pops that we’re unable to detect. Having this insight can help us address problematic areas in our music that may have otherwise gone unnoticed.

You can often remove energy happening below 20 Hz which frees up headroom that you can use to make your track louder. But, a high pass can create their issues (phase distortion). Because of this, it’s worth experimenting with a low shelf — which is gentler on the phase.