The most powerful feature in REFERENCE, the reference-track plugin by Mastering The Mix, is the Level Line. It shows how the tonal balance of your mix compares with a professional reference track, so you can see exactly where your mix has too much or too little energy across the frequency spectrum. Once you understand how to read it, it can speed up your mixing and mastering decisions.
What Is REFERENCE?
REFERENCE is a plugin that lets you load several commercial tracks and switch between them and your mix inside your DAW. It focuses on fair comparison, and its key tools include:
- Level Match: removes loudness bias by matching levels. You can match to the original, match to the quietest track, or set all to -14 LUFS short-term.
- Trinity Display: visual comparison of tonal balance (the Level Line), stereo width and punch.
- Multiple references: load up to 20 reference tracks.
- REFSEND: a companion plugin to send audio from anywhere in your session to REFERENCE.
What Is the Level Line?
The Level Line is part of the Trinity Display. It shows the perceived tonal balance difference between your mix and the selected reference across the frequency range.
- Where the line is above 0 dB, your mix has less energy than the reference in that region, so a boost may help.
- Where the line is below 0 dB, your mix has more energy than the reference, so a cut may help.
In other words, the Level Line works like an EQ suggestion curve. It’s shaped by how we perceive loudness across frequencies, rather than raw measurements alone.
EQ Match vs EQ Difference
REFERENCE lets you toggle how this information is shown. One view shows the EQ move needed to match the reference (EQ Match). The other shows the difference between your mix and the reference (EQ Difference). Both describe the same comparison from different angles, so choose the view that makes the most sense to you.
How to Use the Level Line
- Choose suitable references. Pick well-mixed tracks in a similar genre, tempo and arrangement.
- Turn on Level Match so loudness doesn’t bias your judgment.
- Play similar sections. Compare chorus to chorus or drop to drop, not intro to chorus.
- Read the Level Line and identify broad areas where your mix differs.
- Make gentle EQ moves on the relevant tracks or bus, then recheck.
- Use your ears to confirm. The display guides you, and listening makes the final decision.
For more on choosing references, read using reference tracks whilst mixing.
Fixing the Mix vs Fixing the Master
If the Level Line shows a large difference in one area, such as too much low mid, it’s often better to fix it at the source. Cutting low mids on the guitars or pads usually sounds cleaner than one big cut on the master. Use the Level Line during mixing to catch problems early, then again at mastering for fine adjustments. Our guide to using reference tracks when mastering covers that stage.
The Other Trinity Display Tools
Stereo Width
Shows how the stereo width of your mix compares with the reference in different frequency bands. It helps you spot a mix that’s too narrow or too wide in the lows or highs.
Punch Dots
Show how the dynamics and punch of your mix compare with the reference. This is useful for checking whether you’ve over-compressed or need more impact.
Common Mistakes With the Level Line
- Chasing a flat line. Your mix doesn’t need to match the reference exactly. Different songs need different tonal balances.
- Using a mismatched reference. A sparse acoustic track won’t be a fair reference for a dense EDM drop.
- Making large, narrow EQ moves. The Level Line shows broad trends. Respond with broad, gentle EQ.
- Skipping level matching. Without it, louder audio sounds better and comparisons are misleading.
Using Several References at Once
A single reference can mislead you, because every commercial track has its own quirks. Loading three or four references in the same genre gives a better picture of what a good tonal balance looks like. If the Level Line shows your mix is short of energy in the same region against all of them, that’s a strong sign to make a change. If only one reference disagrees, it may just be that song’s style.
It also helps to switch between references regularly while mixing, so your ears don’t get used to your own mix. Short, frequent comparisons are more useful than one long check at the end.
A Practical Example
Imagine your mix sounds muddy next to a reference. The Level Line dips below 0 dB around 200–400 Hz, which means your mix has more energy there. Rather than cutting on the master, solo a few likely culprits, such as rhythm guitars, pads or the low end of a vocal, and make small cuts there. Recheck the Level Line and, more importantly, listen to whether the mix sounds clearer.
Frequently Asked Questions
What does the Level Line show in REFERENCE?
It shows the perceived tonal balance difference between your mix and a reference track, as an EQ suggestion across the frequency range.
Should my Level Line be completely flat?
No. Use it as a guide to spot large differences. Small deviations are normal and often intentional.
Why do I need Level Match?
Louder audio tends to sound better. Level Match removes that bias so you compare tone and dynamics fairly.
Can I use REFERENCE for mastering?
Yes. It’s useful for both mixing and mastering, especially for checking tonal balance, width and punch against commercial releases.