Spotify Album mode?
It seems like if Spotify silently implemented an album mode to their loudness compensation algorithm!
I was doing some online loudness experiments when I happened to notice that the volume varied on a track in Spotify depending on how I listened to the track. If I browsed my way to the album it was quieter than if I were listening to the same track from a playlist.
Spotify has been criticized for not taking the inherent dynamics within an album into account when compensating for loudness so I was quite happy with my findings. Especially since I just finished master an album for a movie that had huge dynamic differences and I had done some crazy edits to trick Spotify to interpret the loudness in a way so it wouldn’t totally ruin the dynamics of the album and even if it worked it may have sounded better without those edits.
Test it yourself
I made an album with three versions of the same song. The masters are pretty much the same except that they have different loudness targets. The tracks are named with the original files LUFS value, the True Peak value (dBTP) and the Sample Peak value (dBFS). After uploading it to Spotify I created a playlist with just the quietest and the loudest version (if I included all three Spotify handled it as an album play). I played the same part of the track from the Playlist followed by the Album version and measured it all with IzotopeRX and here’s the result.
Note that the original LUFS value is the whole track while the Spotify measurement is made from just the loudest part of the track. I choose to save me some time since what’s matter is that it measures differently and not the values themselves. If I would’ve measured the whole track from the Spotify stream it probably ended up at about -11 (the Spotify target) and not -9LUFS.