Is your mix ready for mastering?

A checklist and analyzer in one. Drop in your mix to see peak, RMS and crest factor, LUFS and true peak, mid and side, phase correlation and tonal balance, compare it with a reference track, and get a list of anything to fix before mastering. The file is analysed in your browser and never uploaded.

  • Free
  • No account
  • Runs in your browser
  • Nothing is uploaded
  • LUFS, true peak, mid/side
  • Reference track

  1. 1Peaks, RMS and crest factor

    Peak meters show the highest point on each channel. RMS is the average level you actually hear, what a VU meter shows. The crest factor is the gap between the two: it tells you if the transients are still alive or already squashed.

    Aim for: Some headroom and no clipping. Before mastering the crest factor is usually higher than on a finished master.

  2. 2Loudness in LUFS

    LUFS measures how loud a track sounds over time. It describes the track; it is not a score. Streaming services play everything at a set level and turn louder tracks down, but that is no reason to make a mix or master quieter: a club track at −7 LUFS is still a club track. Before mastering, what matters is that the mix feels right and the master bus is free of limiting.

    Aim for: No set number. Whatever the mix needs to feel right, with no limiter or clipper doing the work on the master bus.

  3. 3Stereo: mid, side and phase

    Mid is what left and right have in common, side is the difference. The side level shows how wide the mix is, the correlation shows if the channels work together, and the mono check shows what is left on a phone speaker or a club system that sums to mono.

    Aim for: Correlation above 0.3, kick and bass in mono below 150 Hz, and the width in the mids and highs.

  4. 4Tonal balance

    The average spectrum of the whole track, tilted 3 dB per octave (the slope of pink noise) so a balanced mix lies close to the flat line. Add a reference track you like, and the mix is compared with a real release instead.

    Aim for: Within a few dB of the line, or of your reference, unless the sound is meant to be dark or heavy.

  5. 5File: sample rate, bit depth and format

    Deliver an uncompressed file so mastering works with every detail of the mix: compressed formats like MP3 throw detail away, and 16 bit leaves less room under the noise floor. Check that nothing is cut off at the start or the end.

    Aim for: WAV or AIFF at 24 bit or 32-bit float, at the sample rate of your project (44.1 kHz or higher), with silence after the last note.

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Questions

How do I know if my mix is ready for mastering?

Leave some headroom, make sure nothing clips, and take the limiter off the master bus. Check that kick and bass are mono in the low end and that the mix still works in mono. The analyzer checks all of these and tells you what to fix.

How loud should a mix be before mastering?

There is no number to hit. LUFS tells you how loud a track is, not whether the mix is good. What matters is that the mix feels right and has some headroom, with nothing clipping and no limiter doing the work on the master bus. The levels streaming services play at are not targets either: a house or EDM track at −7 LUFS is not meant to be turned down to −14, and the services change their levels over time.

What is LUFS?

Loudness Units relative to Full Scale, the loudness measure in EBU R128 and ITU BS.1770. It weights the frequencies the way the ear hears them, so two tracks at the same LUFS feel about equally loud. Streaming services use it to even out loudness between songs.

What is true peak?

The real highest point of the audio signal, including peaks between the samples that appear when the file is converted to analogue or to MP3 and AAC. It can be a few dB higher than the sample peak a normal meter shows.

How do I compare my mix with a reference track?

Add a released track you like as a reference. The analyzer lays its tonal balance over yours, shows how much more or less you have in each range from sub to air, compares loudness, crest factor and width, and lets you switch between the two at the same loudness, so you hear the difference in sound and not in level.

What are mid and side?

Mid is what the left and right channels have in common, side is the difference between them. A mono signal has no side at all. The analyzer shows the side level against mid per frequency range, so you can see if the width is in the highs, where it belongs, or in the bass, where it can cause problems.

What is crest factor?

The difference in dB between the peak level and the RMS level. A high crest factor means sharp, punchy transients; a low one means the track is compressed or limited. Mixes often have a crest factor well above what they end up with after mastering.

Is my song uploaded?

No. The file is decoded and measured in your browser. Nothing leaves your computer or phone.

How accurate is it?

Loudness, loudness range and true peak follow ITU-R BS.1770-4 and EBU R128, and match the EBU reference signals. Tonal balance is compared with a gentle downward slope, which is a guide, not a rule: a dark or bass-heavy track can be exactly what you want.

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