Im very new to this, I just got a Nexus 5 and wanted to fix this sound issue.
I have read alot posts from this thread and I see that this doesn't fix the call issue (thought I only had 1 friend complaining he could not hear me, other people said it was perfect) but I have some questions.
No, this mod does not fix the low TX level issues reported by many. I suggest you read the section labeled "Thoughts on in-call voice quality" in the OP. While there is no true fix (which needs to come from Qualcomm and/or LG) there are some suggestions that may help lower the occurrence of low TX levels.
So this is a mod for camcorder, but does it also fix other recorders ? For example, in Watsap I sometimes speak in a message, or when I use skype, or another recording app like IgCamera.
The "simple fix" has an effect on any app that requests the "CAMCORDER" audio device. Unfortunately, there is no a-priori way to know what device an app developer selects as the app's recording front-end.
The "advanced fix" has an effect on any app that records audio and requests a single audio effect called "Noise Suppression". I have not yet come across an app (other than Google's camcorder with this mod) that requests this setup.
Have you come across another app whose recording quality is poor?
I also read alot of types like aroma, or L review, so how do I know what I am using ? I just bought this and didnt mod anything, all I know is it uses version 4.4.4.
The term "Aroma installer" refers to an easy way to flash software/mods via custom recovery.
L Preview refers to Google's developer preview of their upcoming ROM, which will be called Lollipop (5.0) once it becomes generally available.
Since your phone runs 4.4.4 you are on KitKat.