So when we're testing them, we're focusing on their ability to deliver exquisite audio, using extremely high-quality audio files, as well as the highest quality from the best music streaming services that deliver hi-res files, such as Tidal. But wired is preferable, because even fancy Bluetooth doesn't have the bandwidth to fully do justice to hi-res music.
They're meant to be paired with the best wired headphones, though many players have Bluetooth too (including higher-res aptX or LDAC versions) for those who want the convenience of the best wireless headphones. The best digital audio players are the tool of choice for those who would rather listen to studio quality sound through a hi-res audio download, on a device that can handle a higher sampling frequency and bitrate to eke every drop of detail from these lossless downloads.
