Metric AB

The Ultimate Mix Reference Tool

The Ulitmate Mix Reference Plugin
The go-to plugin for mix referencing.
Instantly hear how your mix compares to commercially released tracks, mixes and masters with a click of the “A/B” button.
Get deep insights into critical metrics like loudness LUFS and dynamics PSR and a complete suite and analysers including spectrum, stereo and correlation.
Loudness matching levels the playing field and gives you an even comparison volume between all tracks in the playlist and your mix.
It’s the one plugin every producer must have.



Streamlined A/B comparisons

ADPTR AUDIO’s Metric AB is the go-to reference plugin for seeing and hearing how your mix compares to commercially released songs with the click of an “A/B” button.

Streamline your workflow

All the reference meters you need for mixing and mastering. Insert Metric AB on your master channel, key bind the “A/B” button, and quickly toggle between mixes using your keyboard.

Instant loudness matching

Drag and drop up to 16 reference tracks into Metric AB. Match the loudness of your mix and every reference track at once. There are four different loudness-matching modes to choose from.

Precise playback options

Sync the playback of reference tracks with your DAW. Set cue markers to play references at the beginning of different song sections. 


Metric AB’s world-class FFT spectrum analyses features multiple graph types, to provide you with exactly the right visual vantage point to deconstruct the whole audio spectrum, Hertz by Hertz. The innovative zoom link feature works seamlessly to enable maximum viewing space on the UI.


Going beyond traditional Correlation metering, Metric A|B presents a deeper, multiband view of the phase relationship throughout the whole frequency spectrum. This enables us to see which parts of the signal are producing the wider stereo information and which parts are in or out of phase. 

Stereo Image

Metric AB provides a new concept in Stereo Image metering; the Spectral Pan display. This metric allows us to check the comparative left-right gain of the track over the whole frequency spectrum to make sure the mix is balanced. It gives you a visual view of the sonic movement of your track in the horizontal plane and offers insight into how spatial enhancement processors are affecting the signal.



Get tangible information for the dynamic range of your audio with the PSR metric. PSR is the measurement of Peak to Short Term Loudness, and it provides an insight into how compressed the audio is. High PSR values represent a wide dynamic range, whereas low PSR values indicate music is squashed and has a low dynamic range.


Use the real-time meters to compare loudness, Integrated, Short-term and Momentary Loudness alongside Loudness Range, PLR, RMS and True-Peak metrics. Switch to the History graph to see how the loudness metrics play out through the entirety of a track. This enables us to identify problem spots that could be missed when using just the real-time meters. Use the loudness targets to help guide you to achieve the ideal balance of density and dynamics.




A-B Button

Compare your audio with a click of a button. The colour coded button always tells you which stream you are listening to and matches the analysis graphs. Blue for your mix and Orange for reference tracks.

Big playlist

With 16 tracks per preset, there’s more than enough space for an album’s worth of reference tracks. Drag and Drop tracks to load or rearrange the playlist.

Monitor the Mix

Your mix needs to translate on all kinds of systems. Use the monitor section to check the integrity of the mix under all conditions including mono, individual left and right channels and Solo in place. As an extra insight, we also included the “Sides” signal extracted from M/S (mid/side).

Cue and Loop

With four cue and loop points per track, you can quickly jump to the important parts of each track. Drag or Needle-Drop cue markers into position, add a loop marker. Zoom in using the scroll wheel to fine tune the markers for perfect loop lengths.


Isolate the key frequencies of the mix and focus on the details. Use the presets to audition the essential ranges such as bass, mids and highs. Drag the high and low filters to find the exact spot to work on.

Playback modes

Four playback modes designed to suit all your workflow needs. Whether you want to latch to the DAW transport, restart cue points automatically, compare your own mixes or go manual, we got your covered for every eventuality


Select the critical frequency range and fill the screen with a simple toggle action. Or Link the Zoom to the filter range to automatically resize the display area to fit the high and low range. Works for both the Hz and dB scales.

Loudness Matching

Level the playing field between mixes. Our loudness-matching feature is a one-click operation that matches the reference track volume to your mix. This way you can focus of the quality of the audio, and not be fooled by the quantity of volume.

Disk Streaming

Forget about RAM overheads with direct from disk streaming. Did you realize that a typical 5 minute MP3 track can use as much as 250 MB of RAM when working at 96k? Well with Metric AB, you don’t need or care to know because we use disk streaming instead of loading audio files into RAM. It’s harder to for us but easier for you.


Create presets for all music styles, influences and reference points. Export presets into an archive format that includes the reference tracks. This means you can easily move your project into another studio to mix or computer to do the final mix and take your references with you.

Compact GUI

Reduce the footprint and retain access to the essential functions including track selection, gain meters and faders, the monitor section and of course, the A-B button.

Display Modes

Multiple display options for the A | B visualisers. Choose from single, dual and layered modes. Single shows the currently selected stream. Dual shows both layers side by side. Layered shows both streams on the same graph.


Supported Plugin Formats


AAX Native, AU, VST2, VST3


Supported Operating Systems


Apple: macOS 10.11 ‘El Capitan’ through macOS 13 ‘Ventura’

    • Intel x64 or Apple Silicon CPU

Microsoft: Windows 8 through Windows 11

    • x64-compatible CPU

System Requirements


Display Resolution: 1440 × 900px or 1280 × 960px or higher

Memory: 4 GB+ RAM (8GB+ Suggested)

Version 1.4.1 (Nov 17, 2023)
– Added keyboard modifier for PDC sample editing
– Fixed: Crash when clicking Cue and Loop on an empty track
– Fixed: Latch mode behaves like Cue mode
– Fixed: Crash when loading audio files in Harrison MixBus on MacOS


Version 1.4.0 (Aug 4, 2023)
– Full native compatibility for Apple Silicon and MacOS 13 Ventura
– Resizable UI (S,M,L,XL)
– Make Current UI size default option (via UI menu)
Analysis Graphs
– Re-Optimised graphics drawing system – faster and smoother than ever.
Sync Mode
– Sync mode now allows you to place a Cue marker to set the start point for playback – this allows you to select anywhere in the track to start the sync from.
Sync mode now detects invalid song position info and prompts you to start transport to set sync start position. i.e. works in Wavelab etc.
New : PDC Mode – for Hosts which do not report the correct plugin delay compensation to plugins – e.g. Logic PRO when bus tracks are enabled
Method – Click PDC button to open window, you will hear both A+B streams merged – edit the PDC time until you hear the tracks flanging in perfect sync, close PDC window and restart the transport
Loudness Meter and Matching
– Loudness Match buttons now on Compact view (next to Mono button under output meter)
– 4 Loudness Match modes –
A to B,
B to A
Match to target Loudness (you can set the default in the preferences page) – default is -14 LUFS
Match to track with the Lowest volume
Keep meters running when switching between analysis pages (dynamics / loudness)
– (previously Meters restarted when switching between pages)
click transport icon ’latch to DAW transport to active this
Dynamics Meter
– Dynamics metering option to keep meters running when switching between analysis pages
Analysis Modes (Spectrum / Correlation / Stereo Image). – P29 – Video
– You can now select graph types independently for each analysis page – e.g. Plot for Spectrum / Octaves for Correlation / Multi-Band for Stereo-Image
File Compatibility
– M4a audio file compatibility for Windows (Mac has had it since v1)
Filter Bank
– Filters have been re-designed to be more accurate and powerful
– Drag the filter range area with the mouse (left-right motion) to re-position/sweep frequencies
– Use the scroll wheel to edit the size of the filter range (minimum 1 octave – max full range)
– Use the drag ball to move the range (useful for when the range is very small, and you can use the scroll wheel to resize)
– Filter presets now remember last used settings (no need to save as default when switching between presets e.g. bass / mid / high)
– Fixed – high filter band was not correctly calibrated
– Fixed – filters were reducing the volume of the audible range
Organisation –
– Folders for Preset organisation
– Create and save to presets from the preset menu.
– Create and browse presets in user folders.
– Remove Missing Files command on Missing Files menu
Settings and Behaviour
– Revert to A stream when closing plugin (Settings / Default)
MIDI parameters
– All automation parameters are now available to MIDI controllers (previously some parameters were not available in some DAWs)
Loop Markers
– Added – Reset marker to max – right click inside loop region and select
– Added – Delete loop marker – right click on loop marker and select
Text Support for Audio files
– All text now rendered for better clarity / resizing
– Global Languages Character support for audio file names
– Hover over track slot to scroll full name on display (great for long track names which are truncated)
– Fixed – Correlation Window gets stuck on Windows
– Fixed – Filter bank Filter slope does not update user preference / load user default
– Fixed – Youtube Loudness preset now -14 LUFS
– Fixed – Tidal Loudness preset now -14 LUFS
– Fixed – Incorrect Latency reporting of 1 sample (found on v1.3)
– Fixed – Spectrum dB/Hz popup on graph was not always visible (Mac only)
– Fixed – dB range on spectrum analyser can now be set to +36dB (was locked at 0dB on v1.4)
the default should be +36dB – Test – Drag edit Zoom dB between 0 and +36 dB –
– Fixed – Loudness Meters did not update when switching to Hi-Resolution mode (0-18 LUFS)
– Fixed – Cue Select buttons now transmit Automation data and Smart Controls
– Fixed – FFT Weighting now only changes Spectrum Plot mode (previously applied to all bar graphs)
– Fixed – Spectrum Bar Graphs callibrated flat to Pink Noise
– Fixed – FFT Weighting – now only applies to PLOT mode (previously applied to all bar graphs incorrectly)
– Fixed – Crashes due to ‘can’t locate missing file’


Version 1.3.0 (May 14, 2021)
– Fixed waveform calculation failing in Studio One 5
– Added OpenGL user setting for Windows version
– Fixed decibel zoom not working for some spectrum plot modes
– Fixed a potential crash during session launch
– Offline bounce now compensates for latency correctly (when graphics latency enabled)
– Offline boounce now passes A stream to the output when B selected


Version 1.2 (Feb 28, 2020)
– Added notarization support for macOS Catalina
– Fixed preset incompatibilities with 1.1.0
– Fixed default user settings being reset after launching a new instance of the plugin
– Corrected version number in plugin alliance Toolbar
– Settings window tidy up
– Fixed potential crash when validating the plugin in Logic


Version 1.1 (May 20, 2019)
– Fixed a host crash when moving files to a different location
– Fixed Metric AB crashes when starting playback of a song in Studio One
– Fixed Metric AB crash in Propellerhead Reason
– Fixed MP3s not getting loaded in Reference Track
– Added ‘Presets’ sub menu for quick access to user presets
– Added latency compensated graphics rendering option
– Added A and B stream master faders
– Added 36dB and 48dB filter slopes
– Added drag and drop track re-ordered in the playlist
– Added ‘Organise Tracks’ menu option
– Added ‘Apply Current Playback Mode Globally’ menu option
– Added infinite average mode
– Added current playhead position time readout
– Added cue and loop marker position time readouts
– Added ‘Import Folder…’ to load entire fodler of audio tracks at once
– Added frequency marker readout and cross hairs for mouse position on analysis graphs
– Added selecting B track toggles A/B button state
– Added large dynamics target PSR meter readout panel
– Improved compatibility with some MP3 files
– Filter parameters now exposed to host for automation purposes
– Cue points can now be clicked on the waveform overview
– Latch mode playback now starts from the active cue point after a preset or session has been loaded
– Analysis metrics are now computed with loudness match gain applied
– Analysis meter hold times now settable down to .1 second
– Expanded settings and default preferences page


Version 1.0 (Sep 4, 2018)
– Release version

* Please ensure that you have a Plugin Alliance account with an active license before downloading.