I responded to you in another forum. I had same call quality issues, followed these easy steps, now problem gone. Once lg sends out fix I will try it. Here is the workaround for calll issue. Here is the work around from eyeisdasteve XDA
Go to the Dialer
Type in ##3282#
Tap More
Tap Advanced
Tap Edit and enter the handset MSL
Tap EVRC_B
Set the option to Disable
Tap the Back Key and the device will Power-cycle
You can get your msl by type in ##443336772#
Crackling and popping noise disappears after I disable the EVRC B .So far so good