To be honest, I always thought the sound quality was pretty good before and after.
I reviewed this phone fairly well before I purchased it. Most of the reviews regarding audio quality ( during video recording ) were pretty good. Even compared with some HIGHER END PHONES... which I will not name lol.
Your opinion might be more critical than mine though, as you film stuff for your business. I just take random videos every now and then, but I have thought the audio quality was good before and after the update.