CarPlay wired or wireless – which sound quality is better?

Music and navigation are among the most frequently used CarPlay features. Before switching from a wired CarPlay system to a wireless CarPlay system with a "wireless CarPlay Box," many drivers ask themselves the following questions: Is the sound quality of wireless CarPlay as good as wired CarPlay? Which version offers better sound?

The sound quality of wired CarPlay is better than wireless CarPlay!

CarPlay Smart Box Limited was founded in 2014, when Apple first introduced CarPlay. At Apple's WWDC 2016 conference—two years later—Apple explained the difference between wired and wireless CarPlay:

Wired CarPlay uses LPCM (Linear Pulse Code Modulation), an uncompressed audio format that ensures lossless sound transmission.
Wireless CarPlay, on the other hand, uses AAC-LC (Advanced Audio Coding – Low Complexity) – a compressed format with little loss of quality.

What formats are LPCM and AAC-LC?

LPCM (Linear Pulse Code Modulation) is a method of digitizing audio without compression. It provides lossless reproduction of the original sound and is widely used in professional audio and video applications. AAC (Advanced Audio Coding), on the other hand, is a compressed audio format designed specifically for efficient audio data storage. Compared to MP3, AAC uses more modern coding algorithms that provide better sound quality at smaller file sizes. AAC-LC (Low Complexity) is a variant of AAC and is primarily used at medium to high bitrates. It is a lossy compression method that can cause significant differences in sound quality compared to lossless formats such as APE or FLAC. AAC is supported by Apple iPods and many Nokia phones.

That's why wired CarPlay sounds better than wireless.

In addition to transmission technology, other factors influence sound quality, such as the sound source, the vehicle's sound system and signal processing.

Announcement:

CarPlay audio is divided into "main audio" and "backup audio."
As you can see in the picture, CarPlay as the main audio source supports a maximum audio quality of 48 kHz, 16 bit, stereo.