PS: I am very new to this app, so I can't say that I have found the best settings, but so far these settings worked wonders with Cozoy Astrapi + B3Pro1!
EDIT: Just tried direct headphone out again (without the Cozoy Astrapi DAC attachment), the effect is very minimal from this application without the DAC.
Noozxoide app when used with the external DAC makes the biggest difference for LG G3)
On my Samsung Tablet which is running 4.4.2 (Kitkat), under the "Sound" settings is "Music effects", and I have that switched from "MusicFX" to "Noozxoide". This definitely affects the sound output (from Neutron music player).
I had the same rigged up on my S5 when it was on Kitkat. But now that it is upgraded to Lollipop, I can't find that "Music effects" option, and I don't think that Noozxoide is having any effect.
Gotta love upgrades!