Guide · Mastering
Understanding loudness: LUFS, true peak and why −14 is the right number
Anyone who has put an AI song next to a chart hit knows the moment: your own song sounds quieter, thinner, somehow “smaller”. The reflex is to push the level up. That is usually the wrong move – and to understand why, you need two terms.
LUFS: how loud a song really is
LUFS (Loudness Units relative to Full Scale) measure the perceived loudness across the whole song. Unlike a peak meter, which only shows the highest spike, the measurement weights frequencies the way the ear hears them – mids count more than deep bass – and averages over time. The standard behind it is ITU-R BS.1770; our mastering tool measures exactly to it.
Typical values: a modern pop master sits between −9 and −12 LUFS, an acoustic ballad at −16, an audiobook at −18. A raw Suno export often lands between −12 and −16, but varies a lot from song to song – which is exactly what makes an unmastered album feel uneven.
True peak: the ceiling that must not crack
True peak is the highest level that actually occurs after conversion to an analogue signal – including the intermediate values between two digital samples. It can exceed what an ordinary peak meter shows. Lossy formats like MP3 and AAC add further overshoots. That is why distributors and streaming services demand headroom: −1 dBTP is the usual guideline, some services recommend −2 dBTP for very loud masters.
What streaming services do with your song
Spotify, Apple Music, YouTube, Amazon and Tidal normalise playback. Spotify pulls everything to about −14 LUFS, Apple Music to −16, YouTube to roughly −14. A song delivered at −9 LUFS is simply turned down by 5 dB. What remains is the reduced dynamics: after normalisation, the loud master often sounds flatter than a song at −14 LUFS, because the transients were lost in the limiter.
| Service | Target loudness | Boosts quiet songs? |
|---|---|---|
| Spotify (default) | approx. −14 LUFS | Yes, until the true peak reaches −1 dBTP |
| Apple Music | approx. −16 LUFS | Yes |
| YouTube | approx. −14 LUFS | No |
| Amazon Music | approx. −14 LUFS | Yes |
| TikTok / Instagram | heavily compressed, target unclear | – |
Guideline values that may change. What matters is the principle: all services level the loudness.
The right number for AI music
For almost all genres, −14 LUFS at −1 dBTP is the sensible standard: loud enough that nothing needs boosting, quiet enough that the dynamics survive. Two exceptions:
- Club and dance tracks may go to −11 LUFS, because that is how the genre is heard and because DJs do not normalise.
- Acoustic, classical, orchestral benefit from −16 LUFS – more air, more space.
What the number cannot give you: a better mix. If the vocals disappear behind the beat in the original, no mastering will bring them forward. For that you need a new generation run with an adjusted prompt, or stem separation.
Dynamics: the number everyone forgets
In the tool, below the loudness, you see “dynamics” – the distance between true peak and integrated loudness. For a lively pop song that is 10 to 14 dB; for a squashed master 6 to 8. If this number drops below 8 after mastering, the target was too loud. One step down, master again, compare.
How to check it yourself
- Load the song into the mastering tool. The analysis immediately shows LUFS, true peak and dynamics of the original.
- Pick a profile, master, and listen in the A/B comparison with loudness matching. Only then do you know whether the sound got better or merely louder.
- Export as 24-bit WAV for your distributor. MP3 only for preview links and social media.
Rule of thumb: loudness is a decision, not a competition. The streaming services ended the loudness war – you don’t have to keep fighting it.
All guides are deliberately kept general: which models and tools run on your machine depends on your hardware. Questions or corrections? Write to us.