Just recently acquired the 2018 OB 3.6R and really like it so far. I have noticed many folks have expressed on many threads that the HK system is aweful. I do not really find it to be all that bad for my needs/wants - so far. However, I wouldn't mind adding a simple amp and single sub to give it just a little more low end for music. Has anyone successfully done this with the integrated HK system? I read on two threads that there is a proprietary signal structure within the HK system. I don't mind using the high inputs if it can be tapped from one of the three sub speakers or using the 600mv preouts which don't exist, lol.:grin2: