I compared what you wrote to this article: http://www.samsung.com/us/support/supportOwnersHowToGuidePopup.do?howto_guide_seq=7538&prd_ia_cd=N0000463&map_seq=50122
It sees like you've done everything correctly, but can you verify that for me by looking through the steps and trying any that you're not sure whether they've done?
I am trying to connect a samsung PS-WE8200 wireless subwoofer to my HW-D450 soundbar.
When I press the ID SET button for 5 seconds the blue light starts blinking.
With my soundbar off I hold the mute button until the power light on the soundbar flashes.
When I turn the soundbar back on, the link light on the subwoofer just constantly flashes.
After a minute or so, I get a "subwoofer link check" message on the soundbar.
I am also getting the same results when doing the ID SET, with my sound bar next to my sub.
All help is appreciated,