I thought the volume setting was the same for all sound sources, and I was used to adjusting the volume whenever I switched from radio to USB, etc. I just noticed that the volume setting was different for my iPhone/Bluetooth connection than for AM/FM and USB. That's a good thing; I wish all sound sources could be independently set.

Did something change, or was it always that way?

 

Interesting. Id like to test this out later today. I know that on my Mercedes, the sound is the same on all sources, but the radio sound settings (Bass, Treble, etc) are independent

 

I know the EQ and balance are different for each source, never noticed the volumn changing while changing sources.

 

I also notice different sound levels on each source as well but I learn to live with it.