Music and navigation are the two most commonly used CarPlay functions. Many car owners ask the following questions before converting their car's wired CarPlay to wireless CarPlay using a "Wireless CarPlay Box": Is the sound quality of wireless CarPlay the same as that of wired CarPlay? Which one offers better sound?
Wired CarPlay offers better sound quality than wireless CarPlay!

Let's go back to 2014: Apple had just released CarPlay, and the company that owned the CarPlay Smart Box Limited was created. At Apple's Worldwide Developers Conference WWDC2016 two years later, Apple announced the difference between wired and wireless CarPlay.
- The wired connection uses LPCM encoding
- The wireless connection uses AAC-LC encoding

What are LPCM and AAC-LC formats?
LPCM (Pulse Line Coding) is a technology for digitizing uncompressed audio and reproducing the original sound in its original form. It has a wide range of applications. AAC (Advanced Audio Coding) is a file compression format specifically designed for audio data. Unlike MP3, it uses a newer, more efficient encoding algorithm with a higher cost-effectiveness. Using the AAC format can give the impression that sound quality is not significantly reduced, and it is more compact. Apple's iPod and Nokia phones support AAC audio files. AAC-LC is an encoding derived from AAC, primarily used for medium and high bitrates. It is a lossy compression format. Compared to popular lossless formats like APE and FLAC, there is a significant difference in sound quality.
That's why wired CarPlay sounds better than wireless CarPlay.
Furthermore, sound quality is also affected by factors such as the audio source, the car's audio system, etc.

Advice :
CarPlay audio is divided into "primary audio" and "backup audio". As can be seen from the information in the figure, CarPlay as primary audio supports up to 48 kHz, 16-bit, and stereo.
