Why is my Bluetooth and USB volume so much lower than XMRadio.

 

Because your device volume is not turned up. In the future, it would help adding details like what vehicle you are referring to, if your system is OEM or aftermarket, what devices you are using to listen to your music, you know, little details we have no idea about....

 

Sorry. ... 15 Charger with factory uconnect. My device volume is turned all the way up. There is still a noticeable difference in volume.

 

What about normal FM or other sources? Did this just start or has it been this way since you bought it in 2015?

 

Fm and SD card about the same as XM. Have never used AUX. I Bought it 3 months ago. It has been this way since then. USB and Bluetooth are both being fed from Iphone.