Question [Q] Terrible Call Quality

I'm on a rooted stock 4.3 Galaxy SIII (Sprint) - modem is MK3. I get good bars (not full, but 3 or 4 usually) and 4G in my house. But, with the update the actual call quality is awful. Anyone else getting this? Any fixes or workarounds? I've never had spectacular reception here, but this is the worst it's ever been.

Any advice? Anyone?