8 Best Reference VST Plugins for Mixing and Mastering

The best reference VST plugins help you compare your mix or master against professional releases without being misled by loudness. The most useful tools provide fast A/B switching, automatic level matching, loudness metering, frequency analysis, dynamics information, stereo checks, and focused comparison options.

My top overall choice is ADPTR AUDIO Metric AB because it brings listening, level matching, spectrum analysis, dynamics, stereo imaging, correlation, and loudness information into one practical interface. Mastering The Mix REFERENCE 3 is another strong option if you prefer guided visual feedback and a straightforward referencing workflow.

However, no reference plugin can decide what your mix should sound like. The plugin can reveal that your vocal is too quiet, your low end is oversized, your midrange feels hollow, or your master has lost punch. You still need to decide whether that difference is a problem or an intentional part of the song.

In this guide, I will compare the best reference plugins and supporting analysis tools I would consider for serious mixing and mastering work. I will also explain which ones perform true A/B comparison and which ones focus more narrowly on tonal balance, loudness, streaming translation, or final quality control.

For the complete listening method behind these tools, read my guide on how to use reference tracks in mixing and mastering.

What Is a Reference VST Plugin?

A reference VST plugin lets you compare your current mix or master with one or more professionally released tracks inside your DAW. Instead of moving between your session, a media player, and several metering tools, you can manage the comparison from a controlled monitoring path.

The best reference plugins do more than play another song. They help remove the listening biases that make comparisons unreliable.

The most important bias is loudness. When two tracks sound different in level, the louder one often appears fuller, clearer, wider, and more exciting. A proper level-matching function reduces that advantage so you can judge tonal balance, punch, width, depth, and dynamics more fairly.

Useful reference-plugin features include:

• Automatic or manual loudness matching
• Fast A/B switching
• Multiple reference-track slots
• Loop and section matching
• LUFS, peak, and true-peak metering
• Spectrum and tonal-balance comparison
• Stereo width and correlation analysis
• Dynamics and crest-factor information
• Frequency-band soloing
• Blind listening tests

You do not necessarily need every feature. What matters is whether the tool helps you hear the problem and make a better decision without slowing down your workflow.

Best Reference VST Plugins: Quick Comparison

1. ADPTR AUDIO Metric AB

ADPTR AUDIO Metric AB is my top overall choice for detailed reference-track comparison. It combines fast A/B listening with loudness matching, spectrum analysis, stereo information, correlation, dynamics, and several ways to isolate the part of the mix you want to examine.

I find this type of workflow more useful than switching between a reference track and several separate meters. You can hear a difference, inspect it visually, then return to listening without breaking concentration.

Why Metric AB Stands Out

• Automatic level matching creates a fairer comparison between your mix and mastered references.
• Multiple reference slots let you organize several tracks inside one session.
• Spectrum analysis helps identify broad tonal differences.
• Loudness and PSR information helps you compare level and punch.
• Stereo and correlation displays support width and mono-compatibility decisions.
• Frequency filters let you focus on the sub, bass, mids, or high end.

How I Use Metric AB

I prefer to compare one quality at a time. I might first isolate the low end and check whether the kick and bass carry a similar amount of weight and control. I then compare the vocal range, upper-mid intensity, stereo width, and dynamics separately.

This prevents one impressive characteristic of the reference, such as loudness or brightness, from controlling the whole decision.

I also recommend loading references with specific roles. One can represent the overall tonal direction, while another can help with vocal balance or drum impact. Avoid loading several unrelated songs and trying to match all of them simultaneously.

Best for: mixing engineers, mastering engineers, and producers who want a complete reference system inside the DAW.

2. Mastering The Mix REFERENCE 3

Mastering The Mix REFERENCE 3 is a direct A/B comparison plugin designed to help you hear and visualize differences between your track and professionally released references.

The plugin is a strong choice for producers who want a guided workflow without opening several separate analysis tools. It combines level-matched switching with visual feedback that can draw attention to tonal, dynamic, and stereo differences.

Best Features

• Instant level-matched A/B switching for more reliable listening.
• Multiple reference tracks for comparing different sections and sonic qualities.
• Visual analysis that supports tonal and dynamic decisions.
• Looping options for comparing similar parts of two songs.
• DAW-based workflow that keeps the comparison close to the mix.

How I Would Use REFERENCE 3

I would use REFERENCE 3 when I want to check whether my mix belongs in the same sonic space as a professional release. That does not mean matching every curve or visual indication.

If the plugin suggests that my low end is much heavier than the reference, I first listen to the kick, bass, sub sustain, and low mids. I do not place an EQ on the master automatically. The actual problem may sit inside one instrument, the arrangement, or the interaction between several elements.

The same principle applies to width and compression. Visual differences should tell you where to listen, not what setting to use.

Best for: producers who want a clear, modern reference workflow with useful guidance.

3. MeldaProduction MCompare

MeldaProduction MCompare takes a more analytical approach to A/B testing. It lets you compare your audio with external files and with different stages of your own processing chain while compensating for loudness differences.

This makes MCompare useful for more than traditional reference-track listening. You can use it to answer questions such as:

• Did this EQ move improve the mix?
• Does the limiter sound better, or is it only louder?
• Which master revision has more impact?
• Did the new processing chain improve clarity?
• Can I identify the processed version in a blind test?

Best Features

• Automatic loudness compensation reduces level-related bias.
• Blind comparison tests whether you can hear a real improvement.
• External file comparison supports traditional referencing.
• Processing-stage comparison helps evaluate changes across a chain.
• Detailed MeldaProduction control suits technical users.

How I Use Blind Comparison

Blind testing becomes valuable when I have spent too much time making a change. The more effort you invest in a decision, the easier it becomes to assume that it sounds better.

A blind test removes the label and forces you to judge only the audio. If you repeatedly prefer the original or cannot identify the processed version, the change may not provide enough value.

Best for: engineers who want objective A/B testing, mastering-chain comparisons, and detailed control.

4. ADPTR AUDIO Streamliner

ADPTR AUDIO Streamliner focuses on what happens after a master leaves the DAW. It combines loudness and true-peak metering with streaming-platform checks, codec preview functions, target information, and A/B reference comparison.

This is useful because a clean WAV master does not always behave identically after lossy encoding. Codec conversion can change transients and create peak-related problems that were not obvious in the original file.

Best Features

• Platform codec preview helps reveal potential encoding artifacts.
• Loudness, dynamics, and true-peak meters support delivery decisions.
• Streaming and broadcast targets provide practical context.
• A/B reference comparison helps compare your master with released music.
• Loudness matching reduces the advantage of louder material.

How I Would Use Streamliner

I would use Streamliner near the end of mastering, after I am already satisfied with the tonal balance and dynamics. The plugin can then help me examine codec behavior, true peaks, and platform playback.

I would not force every song toward one loudness number. A successful master still depends on the genre, arrangement, transient structure, low end, and desired level of density.

For more context, read my guide explaining what LUFS are and why they matter in mastering.

Best for: mastering engineers and independent producers preparing releases for streaming platforms.

5. sonible true:balance

sonible true:balance is not a traditional A/B player like Metric AB. It is a spectral-analysis plugin that compares the tonal distribution of your track with genre-based targets or custom references.

It also provides information about stereo width, correlation, and mono compatibility. This makes it useful when a mix appears balanced in your room but becomes muddy, thin, or unstable elsewhere.

Best Features

• Real-time and average spectrum analysis shows short-term and overall behavior.
• Genre-based spectral references provide broad tonal context.
• Custom reference tracks create targets from your chosen music.
• Width and correlation information supports mono compatibility.
• Clear visual guidance makes the plugin approachable.

How I Would Use true:balance

I would use true:balance after hearing a consistent tonal problem. For example, if the mix feels hollow, I can examine whether the low mids and central midrange remain unusually weak over time. If the mix feels harsh, I can compare the upper-mid and high-frequency distribution with suitable references.

I would not force every frequency area into the middle of a target zone. Target curves represent broad tendencies rather than mandatory EQ shapes.

Best for: tonal-balance checks, mono compatibility, and producers working in imperfect rooms.

6. sonible true:level

sonible true:level focuses on the relationship between loudness and dynamics. It displays loudness, true peak, dynamic behavior, and reference guidance in a way that makes the trade-off easier to understand.

This distinction matters because two masters can reach similar LUFS values while feeling completely different. One may retain drum impact and movement, while the other sounds flat because the limiter and compression have reduced too much transient contrast.

Best Features

• Real-time loudness and true-peak metering
• Dynamics visualization alongside loudness information
• Genre and delivery references
• Custom reference-track analysis
• Level Check guidance for identifying possible issues

How I Would Use true:level

I would use true:level while testing the final part of a mastering chain. As I increase limiting or clipping, I can examine whether the extra loudness still preserves an acceptable amount of movement and impact.

The meter does not decide when the track sounds ruined. It gives me another way to confirm what I hear.

Best for: producers who struggle to balance loudness, punch, true peaks, and dynamic range.

7. iZotope Tonal Balance Control 3

iZotope Tonal Balance Control 3 is designed to compare the broad tonal shape of your track with genre targets or custom references. It is particularly useful for iZotope users because it connects tonal analysis with compatible processing tools.

The current version expands the reference workflow with a larger selection of genre targets, custom referencing, metering, and integrated control options.

Best Features

• Genre-based tonal targets for broad frequency guidance
• Custom reference profiles based on your own tracks
• Clear tonal-balance display for lows, mids, and highs
• Integrated controls for compatible iZotope processors
• Useful overview for mixes made in difficult monitoring environments

How I Would Use Tonal Balance Control 3

I see Tonal Balance Control as a compass rather than an automatic correction system. It can reveal that the low end, midrange, or high end sits far outside the range of comparable music, but it cannot explain why.

For example, excessive low-frequency energy may come from the kick, bass, reverb, synths, or the entire arrangement. Applying one broad master EQ cut may reduce the symptom while weakening elements that were already balanced.

Use the display to identify the area, then return to the mix and diagnose the source.

Best for: iZotope users, broad tonal checks, and producers who need an additional visual perspective.

8. Mastering The Mix EXPOSE 2

EXPOSE 2 deserves a place in this guide because it supports the final referencing and quality-control stage, but it is important to classify it correctly. EXPOSE 2 is a standalone application, not a VST plugin inserted on your master channel.

You export the mix or master, open EXPOSE 2, and analyze the finished file for potential problems involving loudness, true peak, dynamics, tonal balance, phase, and stereo behavior.

Best Features

• Drag-and-drop file analysis for quick final checks
• Loudness and true-peak measurements
• Dynamics analysis for identifying excessive density
• Phase and stereo checks
• Compare EQ functions for tonal comparison
• Release-oriented presets for different delivery contexts

How I Would Use EXPOSE 2

I would use EXPOSE 2 after exporting the final master. If the application identifies a possible problem, I return to the DAW and investigate the mix or mastering chain.

I would not change a master only to make every indicator appear perfect. Some warnings may reflect an intentional artistic decision. The tool should help you catch mistakes, not standardize every release.

Best for: final quality control before uploading, sending, or delivering a finished master.

What Happened to iZotope Audiolens?

iZotope Audiolens previously allowed users to capture tonal profiles from audio playing outside the DAW and use those profiles with iZotope mixing and mastering tools.

iZotope has removed Audiolens from its current product catalog and moved its main referencing functions into Tonal Balance Control 3. Existing users may still have access to Audiolens, but I would not recommend it as a new purchase or a central part of a future workflow.

This is why Tonal Balance Control 3 replaces Audiolens in the current version of this guide.

Which Reference Plugin Is Best?

The best choice depends on what you want to compare.

Best Overall: Metric AB

Choose Metric AB if you want one detailed plugin for A/B listening, loudness matching, spectral comparison, dynamics, width, and correlation.

Best Guided Workflow: REFERENCE 3

Choose REFERENCE 3 if you want fast comparisons and clear visual feedback without building a large metering setup.

Best for Blind Testing: MCompare

Choose MCompare if you regularly compare processing chains, master versions, or subtle changes and want to reduce expectation bias.

Best for Streaming Translation: Streamliner

Choose Streamliner if codec behavior, platform playback, true peaks, and streaming delivery form an important part of your mastering workflow.

Best for Tonal Balance: true:balance or Tonal Balance Control 3

Choose true:balance for focused spectral and mono-compatibility analysis. Choose Tonal Balance Control 3 if you already work extensively with iZotope products.

Best for Loudness and Dynamics: true:level

Choose true:level when you want a clear view of how loudness, true peaks, and dynamics interact.

Best Final Check: EXPOSE 2

Choose EXPOSE 2 as a final quality-control stage after you have exported the master.

How to Use Reference Plugins Correctly

Buying a reference plugin will not improve a mix unless you use it with a clear method. I follow a few practical rules whenever I compare my work with a released track.

Always Match the Loudness First

This is the most important rule. When the reference is louder, your mix may appear weak even when its tone and dynamics are healthier.

Use automatic loudness matching when the plugin provides it. You can also adjust the reference manually until both tracks feel similar in perceived level.

Bypass Your Master Processing on the Reference

A reference track should not pass through your mix-bus compressor, saturation, clipper, limiter, or mastering chain. Route it directly to the monitoring output or use a dedicated plugin that handles the routing internally.

Compare Similar Sections

Compare a chorus with a chorus, a verse with a verse, or another section with similar energy and instrumentation. Comparing a quiet verse with a dense mastered chorus tells you very little.

Compare One Quality at a Time

Do not ask why the reference sounds “better.” Ask a narrower question:

• Is the vocal more forward?
• Does the kick have more punch or simply more level?
• Is the low end tighter or lighter?
• Does the reference have more upper-mid presence?
• Is the width coming from instruments, effects, or mastering?
• Does the reference retain more movement at the same loudness?

Use One Primary Reference

I recommend choosing one primary track for the overall direction. You can add one or two secondary references for specific characteristics, such as vocal placement or low-end weight.

Do not move between many unrelated references with conflicting balances. You may end up chasing a different target after every comparison.

Do Not Copy the Graph

A spectrum or tonal-balance display can reveal a difference, but it cannot understand the musical reason behind it.

Your reference may use a different key, arrangement, kick, bass, vocalist, or sound palette. Matching its frequency curve exactly can damage a mix that needs a different balance.

Take Breaks

Reference plugins cannot prevent ear adaptation. After a long session, excessive bass, weak midrange, or harsh upper frequencies may start to feel normal.

Take a break, return at a low monitoring level, and check the comparison again before making major changes.

Can You Reference Without a Plugin?

Yes. You can import a professional track directly into your DAW, route it around your master processing, reduce its loudness, and switch between it and your mix.

A dedicated plugin does not make the comparison valid automatically. It makes the workflow faster and provides additional information.

A manual setup may be enough when you only need:

• One reference track
• Basic level matching
• Fast switching
• Simple listening comparisons

A dedicated reference plugin becomes more useful when you need multiple tracks, repeated loops, frequency isolation, integrated loudness metering, stereo analysis, or blind tests.

Reference Plugins Versus Match EQ

A reference plugin compares two tracks and helps you identify differences. Match EQ creates an EQ curve based on the spectral difference between a source and a target.

These tools do not perform the same job.

I prefer to use a reference plugin first. If I hear a tonal problem, I identify its likely source and correct it manually. Match EQ can provide additional information, but I rarely apply a complete suggested curve without adjustment.

The curve may reflect differences in arrangement and instrumentation rather than an actual error.

For a deeper explanation, read how to use iZotope Ozone Match EQ.

Final Thoughts on the Best Reference VST Plugins

Reference VST plugins can make mixing and mastering decisions faster and more reliable, especially when repeated listening has changed your perception of the track.

For a complete professional workflow, I would start with Metric AB or REFERENCE 3. MCompare provides excellent objective testing, while Streamliner, true:balance, true:level, Tonal Balance Control 3, and EXPOSE 2 solve more specific problems.

The plugin does not create the judgment. It gives you a controlled way to ask better questions.

Use references to check tonal balance, vocal placement, low-end weight, dynamics, width, depth, and loudness. Do not use them to erase the identity of your song or copy another production blindly.

If your mix still sounds inconsistent against well-chosen references, you can explore my professional online mixing and mastering services. I use reference tracks as part of a broader decision process that considers the source material, genre, arrangement, artistic direction, and real-world translation.

Frequently Asked Questions

FAQ About Reference VST Plugins