Just got a new Bluesound Node. Very disappointed!

Subwoofer setting was a good suggestion.   Bluesound is actually pretty good for the money in my experience.    You need to spend two or three times the amount to better it.

Good to hear you sorted it out.  Bluesound is good for the money,  you need to spend a good amount more to better it in my opinion.   My next move will be something like a Lumin or Aurender , but that will have to wait until next year as I went a little overboard with upgrades this year.   

Check the Audio settings, there are Bass and Treble adjustments.    Maybe they were invoked by accident.   I have a Vault 2i and it sounds ok with it's internal DAC.  Should not sound as you described 

Something weird is going on....  my Vault 2i ( pretty much the same as Node) was connected to a NAD M51 and it sounded fantastic.   I would do a hard reset on the Node.  The BS / M51 combo was very balanced top to bottom.    Subterranean bass and smooth on top.   It should sound great with that DAC.