What is True Peak vs Absolute Peak (dBFS) and Why is it Important in Mastering?

Recommended True Peak Meters:
YouLean Loudness Meter
youlean.co/you...
DPMeter
www.tbproaudio...
iZotope Insight
www.izotope.co...
True Peak Digital Limiters
iZotope Maximizer
www.izotope.co...
Brainworx bx_limiter True Peak
www.plugin-all...
ITU BS1770-4 True Peak Specifications
www.itu.int/dm...
What is True Peak, when it comes to audio mastering levels and metering? And why is it
important? I’m Lorne Bregitzer, The Audio Professor, and I’m here to explain why.
There’s been a lot of misinformation spread, even from prominent producers on social media,
regarding how loud your peak or true peak should be on your master, and why. Well, I’m here
to clear that up with SCIENCE!
Why does it matter? Well, you’ll see in this video that when your True Peak is too high, your
streaming audio, once converted to MP3 can clip, potentially creating audible distortion, even
when the uncompressed master sounds clean.
First off, what’s the difference between Peak and True Peak?
The Peak is the absolute highest level of your audio in decibels Full Scale. Basically that meter
you see in your digital audio workstation.
True peak is different in that it is calculated utilizing 4x oversampling and measuring the peak of
the interpolated data. The whole process is listed out in the ITU BS.1770-4 document.
When you use a meter that reads the True Peak, you’ll see that the True Peak is at least as high
as your dBFS Peak, or Absolute Peak. It’s usually higher, maybe much higher depending on the
average loudness of your track.
The higher the LUFS or, perceived loudness of your track, the higher your True Peak will be.
Even exceeding 0dB Full Scale. Yes, the True Peak level can be a positive number.
Well, you may wonder why this matters, since the actual absolute level of your track isn’t
clipping. Some people will say that it’s because the amplifier of the D/A converter could distort.
D/A converters usually have enough headroom nowadays, so this really isn’t the issue.
The big issue is with streaming services and listening to MP3s. If you have a track that has an
Absolute Peak of -1dBFS, when the streaming services convert it to MP3, Ogg Vorbis, or AAC,
the audio will potentially clip when being transcoded from PCM to MP3 and back. Basically, a
typical music listening or streaming situation.
You can see here with this track that’s mastered to -1dB Absolute Peak, the MP3 is clipping
and distorted. That’s because the True Peak has reached a positive .2dB.
The Mastered WAV file is not clipping, but once it’s converted to MP3, you can see that the end
result IS clipping due to the transcoding of the lossy audio.
If I mastered this track to the recommended -2dB True Peak, the final MP3 is not clipping.
So when you’re mastering a track, even though the WAV file may sound fine, the streaming or
MP3 version can ultimately be distorting, unless you pay attention to the recommended True
Peak recommendations of each streaming service.
Some digital limiters actually have a True Peak setting that will limit the output at a specific True
Peak. A couple of limiters that do this are the iZotope Maximizer and the Brainworx BX Limiter
True Peak. If you don’t have a digital limiter with a True Peak function, you’ll have to adjust the
output of the digital limiter, manually.
If you’re looking for a good True Peak meter, I highly recommend the free YouLean Loudness
Meter, the free dPMeter, or the iZotope Insight that comes with many iZotope products. I’ll post
links to those in the description.
So what are the recommendations? Spotify recommends a True Peak of -1dB if your LUFS is
about -14dB, and a True Peak of -2dB if it’s higher. All the other streaming services have
approximately similar recommendations. In my experience, I’ve found that you can go up to
-1dB True Peak if the LUFS of your audio goes up to around -12dB LUFS, but your milage may
vary with that.
Hopefully you’ve found this helpful and as always, thank you for watching, like and subscribe.
If you have any questions, feel free to drop them into the comments section.