App: iVolume
Developer: mani.de
Genres: Music, Utilities

Tired of constantly adjusting your music's volume?
iVolume ensures that all your songs play at the same volume level.

iVolume calculates the volume perceived by the human ear for each song of your Apple Music (formerly known as iTunes) music collection. Thereby iVolume gets the most out of the approved Replay Gain algorithm and adjusts your songs accordingly.

* Master of the Genius: iVolume is the perfect companion for your Genius Mixes in Apple Music / iTunes. No longer adjust the volume for background music on parties. No longer dig your iPhone out of your pocket just to modify the music's volume. iVolume takes your music listening experience to a whole new level.

* Compatible With Your Digital Life: iVolume integrates seamlessly with Apple Music / iTunes on Mac and PC, iPod, iPhone, iPad, Apple TV, and AirPlay (aka AirTunes). Most popular audio file formats like MP3, AAC/M4A, AIFF, and Apple Lossless are supported.

* Blazingly Fast: iVolume takes advantage of newest technologies to fully utilize every core of modern multiprocessor machines for optimal performance.

* Avoids Unnecessary Work: iVolume remembers all results ever calculated. Apply changed adjustment settings without the need for re-analyzing your songs.

* Keeps Albums Intact: By using a sophisticated album detection algorithm iVolume optionally adjusts albums as a whole to keep the intention of the artist. This method is particularly suitable for adjusting gapless live albums.

* Highly Configurable: Create groups to apply individual fine tuned settings to any specified subset of your songs.

* Awesome Usability: All the features above are fun and incredibly easy to use through a modern and clear user interface.

Frequently Asked Questions:

Q: How exactly does iVolume adjust my songs?

A: iVolume effectively repairs the built-in 'Sound Check' function of Apple Music / iTunes. Information about the loudness is stored by Apple Music / iTunes in a tag named iTunNORM inside your songs. This information is used for playing a song a bit louder or softer at playback time whenever Sound Check is turned on. Apple Musics / iTunes' loudness analysis is very fast but unfortunately not very accurate so that Sound Check is not satisfying out-of-the-box. That's were iVolume comes into the game: iVolume re-analyzes every song with a professional algorithm that's oriented on the acoustic perception of the human ear and iVolume then permanently replaces the information in the iTunNORM tag of your songs with perfect values.

Q: Is there any loss in quality to my songs?

A: No. iVolume does not re-encode your songs. It just replaces the information in the iTunNORM tag with perfect values. This information is used at playback-time to play a song softer or louder whenever Sound Check is turned on.

Q: Do I need iVolume to play my songs?

A: No, you just let iVolume run once (or every time you've added new songs) over your library. Then you play your songs as usual with Apple Music / iTunes, your iPod, iPhone, iPad, or Apple TV. You just have to make sure to have Sound Check turned on in Apple Music / iTunes or on your playback device so that the adjustments made by iVolume take effect.

Q: Are copy protected AAC songs bought from the iTunes Store supported?

A: Songs purchased before mid 2009 from the iTunes Store may be DRM-protected (file extension .m4p). Unfortunately there is no way for applications to read raw sample data from copy protected songs. If this would be possible, it would not be a copy protection anymore. But to calculate the perceived loudness of a song, iVolume needs to read the sample data of that song.
So copy protected songs can not be automatically adjusted by iVolume. However you can still manually adjust them by hand.
In the meantime all songs offered by the iTunes Store are in DRM-free "iTunes Plus" format. Songs purchased in this format can be analyzed and adjusted fine with iVolume.
Rented songs (Apple Music) are DRM-protected, though.

Release notes:
• Compatibility with macOS Big Sur
• Runs natively on Macs with Apple Silicon processor
• Design improvements
• Performance and stability improvements
• The headphones attached to the main window can be turned off