Apple Music’s Streaming Audio Quality ⇥ slashgear.com

Chris Davies of SlashGear got a preview of Apple Music following Monday’s keynote. This little thing intrigued me:

Apple Music will be at 256 kbps. In comparison, Beats Music uses a 320 kbps bitrate, as does Spotify, while Tidal offers a high-bitrate option.

This isn’t quite the even comparison it seems to be because all of these services — and Rdio — use different encoding formats. Beats Music is, or was, using the MP3 format, along with Rdio. Spotify uses Ogg Vorbis, while Tidal is unclear about what file format its lossy tier uses (FLAC is used for its premium offering). Apple Music will be in the same 256 kbps AAC files used on the iTunes Store.

What’s important to note about comparing these services is that the AAC format is generally better at preserving sound quality than the MP3 format. This has something to do with a smaller block size for a more accurately-detailed compression, and better handling of higher frequencies. A good rule of thumb is that the bitrate of an AAC file sounds approximately equivalent to the next level up in MP3, so a 256 kbps AAC file sounds as good as a 320 kbps MP3. But, at that end of the audio encoding spectrum, you’re really going to have to squint with your ears to tell the difference.

Update: Bruce Houghton over at Hypebot added a particularly stupid comment to this news:

Apple Music will stream at 256kps or 20% below the 320kps industry standard usually delivered by Beats Music, Spotify and other music streamers.

First of all, as discussed above, comparing different codecs on bitrate terms alone is idiotic. Second of all, comparing bitrates by percentage is meaningless. The implication seems to be that Apple Music streams are 20% lower quality than other services, but bitrate quality is not linear. It’s not even wrong; it’s just irrelevant.