I had the same 2nd Mic problem with my ZR. It came with the 10.3.1.a.2.67 firmware out of the box. I went ape trying to find a solution since January. Luckily i found a post from user "nigoc" in Sonymobile forums who said downgrading the phone to 10.1.1.A.1.310 (JellyBean 4.1.2) solves the problem. I did it, and heck he was right. My camera now works as expected. All those "streaming-like" sounds in my video recordings are gone and the sound quality is very good.
I'm attaching the /etc/system/snd_soc_msm/snd_soc_msm_2x_fusion3 file from my phone. Hope it works in 4.2.2
i guess maybe cm/fxp devs used yuga (xperia z) config on zr, and that's causing a problem???
anyway, too tried to try now, later... later...