Can I improve the sound quality from the aux input?

[Sepanger]

I've recently fitted a Bavarian Automotive carplay box to my car. This uses the aux input for its sound via the intermediate wiring used for its installation. (The external aux in plug has to be used to enable this, though it's not connected to anything)
It all works, but the sound quality is poor, and I've had to crank up the input setting to get sensible volume settings. The sound from the jukebox and SD card inputs is just fine.
Does anyone have any suggestions, or is aux in just generally poor?
Thanks.

[Elansear]

Hi, think you will find that the aux input is analog, whereas the others, SD card or USB socket are digital. Therefor aux will be a poorer quality.

[Sepanger]

Thanks for clarifying.
Is there any way around this?
The carplay unit is good but spoilt by the crappy sound.


Edited to add that I found the setup menu for the device, not Android Auto, and I was able to boost the output and reset the equaliser to flat. It was supplied set as 'pop'.
The sound is better now.