my system required me to connect the wireless subs via Bluetooth to the bar.
most subs have a knob on the back to turn it up.
your audio system my have the sub turned off or set very low.
in my experience tv shows or tv programming in general do not have much bass. for full effect play music or movies.
your system is highly regarded. seems as if a bit of trouble shooting is required.
is the blue light on, on the back of the sub? this indicates Bluetooth connection with soundbar.
What content are you playing on your tv? Can you test with something that has 5.1 audio? Maybe with Amazon or Vudu app?
Since you already have the sub at +6, can you also set the front L/R and center to -2? Also try the Pop equalizer setting on the Samsung app if you use that.
With the soundbar directly connected to the tv and using ARC, the sub should be active with apps like Amazon or Vudu when playing movies with 5.1 audio.
Also, if you haven't already, try connecting your cable box directly to the soundbar.
If just playing mono or stereo, like for broadcast tv shows, try switching the sound mode on the N950 between standard, surround, and smart, to see if any of the upmixing features help.
My N950 died, and I can't recall how well the sub worked on the upmixing modes. Definately got bass with 5.1 content.
Sub location in the room can affect bass frequencies. Check at the sub speaker when playing known 5.1 to see if it is even moving. If it is, try putting the sub in one of the room corners. That helps reinforce the bass. If the speaker is not even vibrating slightly, the sub is probably defective. Return it for refund.