Crossfading is a technique that creates a smooth transition from one sound to another. This audio effect works like a fader but in opposite directions, meaning the first source can fade out while the second fades in, and it all mixes together.
It’s often used in audio engineering to fill in the silence between two tracks, or even blend multiple sounds in the same song to create smooth changes rather than abrupt ones.
DJ’s often make use of the crossfading effect between tracks to enhance their music performance and to make sure that there aren’t any sudden silent gaps that could annoy the audience or the people on the dance floor.
Crossfading is sometimes spelled cross-fading and referred to as gapless playback or overlapping songs.
Note: Crossfading is the opposite of “butt splice,” which is when the end of the one piece of audio is joined directly with the beginning of the next, without any fading.
Analog vs Digital Crossfading
With the invention of digital music, it has become relatively easy to apply crossfading effects to a collection of songs without needing any special hardware or audio engineering knowledge.
It’s also much simpler to do compared to crossfading using analog equipment. If you’re old enough to remember analog tapes, crossfading required three cassette decks – two input sources and one for recording the mix.
Software Used to Crossfade Digital Music
Depending on what you want to achieve, there are several types of software applications (many free) that you can use to apply crossfading to your digital music library.
The categories of audio programs that often have the facility to create crossfades include:
- DJ Mixing Software – As well as gapless playback of your music files using crossfading, DJ programs also have other sound processing tools that you can use such as beat matching (BPM detection), time stretching, and sample looping.
- Media Players – Many jukebox software programs like iTunes, Windows Media Player, and others come with an automatic crossfading feature that can be used not only for music files, but also for your playlists too. For ease-of-use, software media players are probably as simple as it gets.
- CD Burning Software – Some DVD/CD burning software can be used to burn digital audio files to audio CDs that have crossfading. This is a type virtual crossfading that’s added to the music during the burning session. The process does not alter any of your original files, so they remain unchanged on your computer’s hard drive.
- Audio Editors – Audio editing software such as the free Audacity program can be used to create new mixes that have crossfaded tracks. This type of software is a bit different from the other examples above (excluding audio CD burning) – you are actually creating a new digital audio file, rather than just adding a non-permanent effect.
- Online Music Services – Some online music services provide free application downloads that can crossfade streaming audio using extra buffering. Spotify is one example (see how here) that provides this facility in both its desktop and mobile software.