I didn't see the first series, but after reading how much it has been enjoyed here, I have been watching it for 45 minutes, and I have no idea what is going on.
Samuraisan - I use subtitles most of the time these days, and think you might find them helpful. The dialect used is quite broad, and I agree, can be difficult to understand. Give it a try.
I hadn't seen the first series either but will stick with it. For such high class writing and acting, I'm surprised the sound was so poor. Hope it doesn't continue like that for the whole series.
Sounds like a general issue. I've increasingly had to use subtitles for some TV but found it ok with my laptop right near to me on catch up. My couple of years living in Yorkshire might have helped too :)