Wired Headset Mic Unusable
I'm using CarbonRom is both HD and HD+ and this problem is the same for both. Today, I made a phone call and the person wasn't getting enough volume and the words were garbled. I tried the headset with Google Voice search and VoiceToText in other apps. It is evident that the mic isn't working correctly. I tried a different wired headset and the result was the same. For reference the headsets are a Klipsh S4A and stock that comes with Galaxy S3. The onboard mic works as expected. I paired a Bluetooth headset and, surprisingly, that worked the best of all.
Sometimes this is a kernel issue. I reflashed the rom without the fstrim kernel and that made no difference.
I am thinking that this is a bug that may be in the various Android, custom roms and that's why I didn't post only in CarbonRom thread. It may even be a problem with stock. I don't think there are many people that use a wired headset with mic. I make phone calls with MagicJack.
Maybe a few people that have a headset with mic can try and report back if this is a problem for the particular rom they are using.