Very low to no volume after upgrade to 6.0 marshmellow I recently upgraded to 6.0 and since then I have had very quiet volume on calls and even when listening to music. 

I have everything turned up to maximum but still very quiet like it is on low.

Has anyone experienced or heard anything like this or know of some ways on how to fix this and make the volume louder? 

I am also running a Droid Turbo 2.
Fixed it. 

You do need to go in and delete the cache after an update. Everything sounds correct now.

Get into bootloader


Power off phone
Press and hold Vol down , press power button until you seebootloader
(3 happy androids on skateboards at bottom of page). Release vol
down.


Open Recovery


Select Recovery by using vol down, press Power to select.
Wait. This takes a while.
You will now see a screen with a picture of a phone with a red
exclamation mark on it. Press in power button, keep it pressed, and
press volume up button shortly (do not keep it pressed). Release
power button.
You will now see a menu with yellow text on-top of it.
Select Wipe Cache partition with vol down. Press Power to select.
Now it wipes the cache partition. Done!
It should now have marked Reboot system now. Press Power to select.
Phone will now reboot to normal mode.