MetricAB lets you A/B your mix against a reference track in real time, with loudness matching and spectrum overlay — for $79. MixDiagnose compares your mix to genre-matched references for free and tells you, in plain English, exactly where you differ and how to fix it. One is a listening tool; the other is a diagnostic tool. Here's how they compare.
Both MixDiagnose and MetricAB compare your mix to a reference — but they do it differently. MetricAB is a real-time A/B plugin. You load a reference track, put MetricAB on your master bus, and switch between your mix and the reference with matched loudness, spectrum overlay, and phase alignment. You use your ears to hear the difference. MixDiagnose is an automated analysis. You upload your mix, it compares your frequency balance to genre-matched references automatically, and tells you — in specific dB values per band — where you differ and how to fix it. One is a controlled listening test; the other is an objective measurement. They solve the same problem from opposite directions.
| Feature | MixDiagnose | MetricAB |
|---|---|---|
| Real-time A/B against a reference | ✗ | ✓ Instant switching in your DAW |
| Loudness-matched comparison | ✓ Automatic (LUFS-normalized) | ✓ Real-time gain matching |
| Spectrum overlay (visual) | ✓ Static report | ✓ Real-time, live |
| AI mix analysis | ✓ Automatic issue identification | ✗ |
| Genre-matched references (built-in) | ✓ Auto-selected per genre | ✗ You supply your own reference |
| Frequency balance with dB offsets | ✓ "You're +4 dB at 250 Hz" | ~ Visual overlay — you interpret |
| LUFS / loudness measurement | ✓ Integrated, true peak, streaming targets | ✓ LUFS, dB, peak |
| Dynamic range / crest factor | ✓ | ~ Limited |
| Stereo width per-band | ✓ Measured and reported | ✗ |
| Phase / mono compatibility check | ✓ Measured and reported | ✗ |
| Frequency masking detection | ✓ | ✗ |
| Specific fix recommendations | ✓ "Cut 250 Hz by 3 dB on bass" | ✗ You interpret and decide |
| Severity grading | ✓ Critical / Moderate / Minor / Ideal | ✗ |
| One-click auto-fix | ✓ Corrective EQ on uploaded file | ✗ |
| Runs as a DAW plugin (VST/AU/AAX) | ✗ Web app | ✓ |
| Phase-aligned reference playback | ✗ | ✓ Auto-aligns timing |
| PDF reports | ✓ | ✗ |
| Platform | Any browser, no install | Windows / macOS DAW |
| Price | Free for 3 analyses/mo · $19/mo Pro | $79 one-time |
| Best for | Objective mix diagnosis with specific fixes | Real-time A/B listening against a reference |
MetricAB (by Mastering The Mix / Plugin Alliance) is a reference-comparison plugin. You load a reference track — a professionally mixed song in your genre — put MetricAB on your master bus, and it lets you switch between your mix and the reference in real time, with loudness automatically matched so you're comparing tonal balance, not volume. It overlays both spectrums so you can see where your mix differs, and it phase-aligns the reference so you can A/B specific sections precisely.
This is a genuinely useful workflow. Loudness matching matters — if your reference is louder, it'll sound "better" even if it's not, and you'll chase the wrong fix. MetricAB removes that trap by gain-matching, so you hear tonal and dynamics differences only. The spectrum overlay shows you where your mix has more or less energy than the reference. For an engineer who trusts their ears and knows what they're listening for, it's a fast, controlled A/B.
The limitation: MetricAB doesn't analyze anything — it gives you a controlled listening test and a visual overlay, but you still have to interpret both. It won't tell you "your low end is 4 dB too hot" or "your stereo collapses in mono" or "you're 2 LUFS short of the Spotify target." It also requires you to supply your own reference track, and it doesn't measure phase or masking. And because it's a listening tool, your room and ears still affect the result — if your monitoring is off, your A/B is off too.
MixDiagnose takes the comparison a step further. Instead of requiring you to supply a reference, it automatically compares your mix to genre-matched references — built-in profiles for pop, rock, hip-hop, electronic, metal, and more — and tells you, in plain English, exactly where you differ: "Your low end is 4 dB too hot at 60 Hz relative to the rock reference. Cut 3 dB on your kick and bass." Every band, every offset, with a specific fix.
It also measures LUFS, true peak, dynamic range, stereo width per band, mono compatibility, and phase — all in one report, with severity grades (Critical / Moderate / Minor / Ideal) and a one-click auto-fix that applies corrective EQ to your upload. Because the analysis runs on the file itself, not through your monitors, your room and ears don't affect the result. It's an objective measurement, not a listening test.
The trade-off: MixDiagnose isn't real-time and doesn't run in your DAW. You upload, wait ~30 seconds, and read a report. You can't switch back and forth between your mix and the reference while you EQ — you get a static diagnosis and apply the fixes in your DAW. For continuous A/B listening during a session, MetricAB is the better tool.
MetricAB and MixDiagnose are complementary — one gives you ears, the other gives you answers. MetricAB is the tool you use during a session: load a reference, loudness-match, A/B back and forth while you EQ. It's a listening workflow that depends on your ears and your room. MixDiagnose is the tool you use before or after: upload, get an objective report with specific dB offsets and fixes, and know exactly what to change — no interpretation required.
The best workflow uses both. Run MixDiagnose first to get the objective diagnosis — fix the Critical and Moderate issues it identifies. Then load a reference into MetricAB and A/B while you apply the fixes, using your ears to confirm. MixDiagnose tells you where to cut; MetricAB confirms it sounds right. At $79 one-time for MetricAB and free (or $19/mo) for MixDiagnose, the combined cost is under $100 to start.
If you can only pick one: choose MetricAB if you have good monitors, trust your ears, and want a real-time A/B against a specific reference. Choose MixDiagnose if you want an objective AI diagnosis of your whole mix — with genre-matched references, specific dB offsets, and fixes across loudness, dynamics, stereo, and phase — for free.
3 free analyses a month. No signup, no card.