Thanks again everyone for the great responses. Your information gives me a lot to work with at next practice. Just to be clear, the tone is awesome just no real volume. I realize a 1x15 cab may not be optimal but when I connect my Markbass to the 1x15 there is much more overall volume. On the Markbass gain is set to 10 o'clock and master set to 1 o'clock. With the D800+ I adjusted both the gain and master to 2 o'clock and still the volume was much lower overall than the Markbass. I did not go over 2 o'clock as I saw the Limit LED flashing and thought I was pushing the amp too much.
Regarding the EQ, it is set pretty much set flat with the Voicing set to around 10 o'clock. I have a Fender Bassman Neo Pro 6x10 4 Ohm cab I normally use and will try using the Fender cab next practice. I really want to make this work as the tone is just what I am looking for. Even my band mates love the tone