Purchased an xduoo x5 a year back as well as an Ifi black label....i have an old s7 which is used for only music transport and a V20 for daily....never noticed it i quess because most my listening sessions on the go were brief but i connect my dacs to either phone it will prompt me to select usb...

Ive soldered new plugs on various headphonese before and most typically have the common ground and lf and rt....however my bass editions upon stripping back the shielding have what appears to be four wires.....these have no mic so im at a loss to finish my project....google was no help so thus i...