low bass on Audio Research LS27

I had an LS26 for awhile. It had a magical midrange and lovely open highs, but for me the low bass was not weighty or extended enough (actually it was pretty anemic for my -3db at 28Hz speakers). I replaced the LS26 with a Krell KCT SS pre, and got the bass I wanted, but that magic on vocals is gone and I miss it. How is the bass on the LS27? Do I need to save for a used Ref 5 to get what I want? Thanks for your input!