Well, let's see. KraKen isn't designed for stock-based ROMs. Less designed for stock-based Lollipop.
I've heard about that issue when folks would use an AOSP/CM kernel on CloudyG3 LP, like Nebula for instance. I don't remember if anyone got around the sound problem.
Simply put, you're trying to use a kernel that (I assume) targets Marshmallow. The fact that it partially works is nice. However, if a kernel not designed for a particular Android/ROM doesn't work properly it wouldn't be a surprise and falls under the category of "too bad".
Since you're running stock-based Lollipop it makes more sense to try kernels targeting that (if you haven't already). Far as I know the Lollipop versions of Xceed, Solid, and Gabriel are still available for download.
LG G3 D851, OctOS-M ROM, Tapatalk 4.9.5