Good thing you are still within the generous return policy.  Sonos is not for everybody. 

I would think you hooked something up wrong as there is no way it should sound bad. I would check your TV settings and make sure your hdmi cabled aren't from the dollar store. Could be your firmware from your TV us not up to date. You never mentioned what other speakers you have hooked up. Just the soundbar is not quite the best sound by itself, it's what speakers you run off of the Ark. Try a set of 100s or for best sound purchase a set of 300s.  Check your TV setting first though and make sure you have a strong isp..