ZMan2k2
1000+ Head-Fier
I had a Sony Z5 Compact and though it was not as bad as say a LG G4 they were not good either. I am currently using a V10 (single Sim German version) and my old iPhone 5. Its pretty hard to get good android phones with good sound quality.
The V10 is pretty good but the problem I have with it is that I listen to a lot of old recording of classical music from the 70s and 80s (the Karajan box for example). And some of these recordings are just not very loud. As a result I cant really enjoy them outside on busy streets with my V10. The old iPhone 5 on the other hard is very loud.
I unplug the left earpiece on my IEM's right now, and it put's the amp into high output mode. I have a short, 6" cable, coming from China soon, that I will plug in, trick the amp into high output mode, then plug my IEM's into that cable. It's short, fits in my IEM's case, and will solve my problem of fear of wearing out the connector on my left earpiece.
Check your HiFi DAC button when you plug in. If it says it's in "Normal" mode, you're not using the built in amp. You have to get it to either the "High Impedence" setting, or the "External device" mode, to gain use of the built in amp. There was a post in the V10 thread, if you're rooted, on how to boost the volume by going into the "mixer_paths.xml" file, and changing a couple settings in there.