So it's been working fine louds as hell but out of no where the sound threw the usb is really low unless I fast forward it a little and then it's back to Normal but in FM or XM ITS NORMAL. Its really annoying having to fast forward it to hear it loud.

 

how did you wire it?..

 

Line converter

 

That is weird, same thing happen to me this past Friday. I had my iPhone 6+ hooked up through usb, the song started and I realize I was at volume 20 and it sounded like it was at 10. So I restarted the song and and it went back to loud/normal sound, If I skipped to the next song it would start at really low volume again but if I let the song continue to the next song the volume remains normal. I ended up getting to my destination, shut car off, ran my errand, re-started the car again and it all went back to normal.

I also have a powered sub, using a LOC.

 

Thought I was the only one and now it's working fine lol

 

why hook-up your phone via usb when you can just use bluetooth?

 

1. Charge the phone
2. Quicker response changing songs
3. Probably better quality audio as well

 

the bluetooth sounds so bad

 

This ^

 

Are you guys with low volume using an iPhone? Its a known issue that certain apps (with Facebook being the most prevalent) will "dim" the output volume of your phone regardless of how its connected (headphone jack/usb cable). This is somewhat random, too.

Quitting the app in question will restore normal output volume.

Just a thought.