[Q] Use Earpiece as second speaker?

So I'm coming from the Nexus 5 and it's speakers weren't the greatest but with the "Surround Sound Mod" (enabling the front earpiece as a second speaker) it definitely helped out. The method to do this is to edit the mixer_paths.xml file in /system/etc. Unfortunately though, I can't find that file anywhere in that directory. Is this file somewhere else on the phone? Or is there another way (app, mod, etc.) to achieve this. It would really help out the output volume of our phone