Apple CarPlay

[Gorrillaas]

Does the audio quality improve while using Apple CarPlay to listen to music in your vehicle? Does use Bluetooth to stream music from your phone provide equivalent audio fidelity? Thank you!

Does Apple CarPlay also use Bluetooth?

[StartingWar22]

Wireless CarPlay uses Bluetooth for the initial setup of the connection, but then employs wifi to perform its intended functions.

I was contemplating doing some comparisons, mostly focusing on service comparisons rather than comparing Bluetooth and CarPlay. However, exploring the latter may also be intriguing. I would want to compare the audio quality of the same song on Apple Music, Spotify, Amazon, and via direct Bluetooth connection, since certain songs provide a really immersive experience.

[DivineStripe]

Given that the file available on streaming platforms is identical to the music file that has been mastered in the same manner, there will be no noticeable difference. To get high-resolution music (sampled at 192 kHz), you would need to use a service that offers such material. Apple Music and Tidal HQ are two platforms that provide a library of Dolby Atmos encoded high-resolution audio. When using carplay for streaming, the audio is restricted to a maximum sampling rate of 48 kHz.
Note that carplay supports lossless transmission at a sample rate of 48 kHz, whereas bluetooth typically compresses the audio stream in a lossy manner on the device end and expands it on the head unit. This means that even if you use a high-quality audio source, the compression of the stream will affect the final audio quality, except for the latest 2022 Quallcom codec which allows lossless compression at a sample rate of 44.1 kHz.

[newjimmy54]

I acknowledge the points you made. However, my comparison primarily focuses on how the automobile comprehends and analyses the music it is playing from different sources. I have performed a comparative analysis of a song on both Amazon and Apple Music platforms, and I have seen distinct variations in the surround sound impact experienced via the headrests. Similarly, both Amazon and Spotify were involved, but Amazon emerged as the victor. It is mostly a sequential analysis of each individual track. Not significantly distinct, but rather marginally altered.

Which codecs are compatible with the car? Will the content benefit from Atmos encoding, or is that feature disregarded and left to the Meridian system to choose the optimal playback method?

[Gorrillaas]

Thank you! It seems that all of you possess a comprehensive understanding of the subject matter being discussed. I just acquired a 2024 RR SE, which is the bigger variant. I have attempted to connect my iPod to the USB port in the central console (without use Bluetooth), but, the Media screen fails to acknowledge my direct USB connection. My iPod can only be linked to the media system via Bluetooth. The lack of a direct cable connection from the iPod to the automobile is frustrating since it would provide superior sound quality compared to a Bluetooth connection. Perhaps I am overlooking a crucial aspect? Perhaps I am connecting my iPod to an incorrect USB port in the vehicle. I would really value any direction or advice. Thank you!

[veroguittar]

JLR advises using USB mass storage linked to any of the USB connections for optimal playing quality.

[Gorrillaas]

Extremely helpful! Thank you to everybody!

[dontito]

Apologies for diverting the discussion, but I would want to inquire about the feasibility of using the Spotify native application inside the Pivi system. Will the same limitations as streaming over WiFi and the cellular network likely hinder lossless streaming?
Is there no option available to adjust the bitrate for Spotify?
Thank you.

[DivineStripe]

Intelligent reasoning, however, let us further explore the topic.
In order to achieve true lossless quality, beginning from CD quality, we would want Spotify to provide us with an uncompressed PCM stream consisting of 16-bit audio samples at a sampling rate of 44.1 kHz. This stream would need to be separate for the left and right audio channels. The music data is sent at a rate of 1,411,200 bits per second. When accounting for network overhead, the total data rate is slightly less than 2 Mbps, which is sufficient for a mobile network. Based on the current rate, the duration of Led Zeppelin's "Immigrant Song" being 2 minutes and 26 seconds will result in an approximate file size of 26 megabytes.
Spotify transmits a compressed file that is less than 2 MB.
Regardless of the proximity of the app to the headunit, our options are limited by the streaming service provider. If there were an application that offered high-resolution streaming and was compatible with the headunit...

[DivineStripe]

Spotify attempted but was unsuccessful in promoting the "HQ" streaming plan, which would automatically set the audio quality to 320 kbps.