Some thoughts on MP3 and mastering

There’s been a small discussion on Twitter lately about the loudness wars, dynamic range and distortion in mastering. Because Twitter limits your thoughts to a few characters, I figured I’d do a short post here instead.

Rather than get into the loudness war debate which has raged on for a decade, I’d like to touch on a subject that you don’t hear about much…MP3s.

It’s safe to assume that music is being listened to on MP3 more than WAV or even vinyl these days. They save hard drive space, quicker download times and let’s face it, most people can’t hear the difference between 320kbps MP3 and WAV anyway.

The thing is however, most people aren’t listening at 320, they’re listening at lower bit rates. Soundcloud has become somewhat of the standard for searching out new music and they are converting to 128kbps.

If you take a master WAV that’s been mastered to peak at 0dbfs and convert it to 128kbps MP3, it’s now peaking at least 2db’s over zero! That’s audible distortion and people are now accustomed to hearing it daily.

This is from Soundcloud’s own help section:

Just uploaded and my track is distorted

Sometimes our transcoding system can create audio artifacts, as we transcode all tracks to 128 kbps mp3 for streaming playback. Uploading a lossless or high-quality lossy file will usually reduce these to a minimum, but unfortunately there’s not much we can do for the handful of individual tracks that are…

And Spotify:

What bitrate does Spotify use for streaming?

We use the Ogg Vorbis format for streaming. There are three quality ratings that we use:
q3 (~96 kbps) Spotify mobile “Low bandwidth” setting
q5 (~160 kbps) Spotify Desktop standard streaming quality
q9 (~320 kbps) Spotify Desktop “High bitrate” setting available with Spotify Premium
 
Ok, so you have to pay Spotify monthly to not hear distorted tracks, fair enough…
 
The only way you’re going to hear MP3’s that aren’t distorted is when the labels decide to account for it and either master quieter FOR MP3, or offer two versions.
 
To put things into perspective on how out of control things have gotten, think about your average bedroom producer who’s trying to match his levels to commercial masters and drives his limiter into distortion to get there, then uploads it to Soundcloud and gets more distortion on top of distortion…
 
The question I pose is, do people care? Is this the standard now? The only way anything will change regarding the loudness wars and internet playback distortion is when the consumers speak up and demand change. Labels will listen.
 
- Mike Bell @ Darkart Mastering