Till now there has been not many sound MODs for Lollipop Z2. But you can give a shot at this http://forum.xda-developers.com/showthread.php?t=3067061.
If it helps, gr8! oter den that, you have to wait for the devs to come out with LP mods as I be...
1. reboot to recovery of ur choice(on reboot,green light appears with vibration,press either Vol+/Vol- (vol+=cwm;vol-=twrp)to boot to recovry while green light is on) and there wil b option for backup. Backup all by checkmarking(compression cn b i...
everything fine till now. been using for a month now. just to be cautious, do a backup b4 flashing.
Results may vary 4m ROM to ROM but it shud be fine. And if ur on stock based ROM, shud be fine.
Just give it a shot buddy!
Sent from my D6503
working gr8 on RomAur V8.. been waiting for 4K & TSvideo.. gr8 work choco!!:good::D