most towers that can go low to 40hz or below will sound great with music and w/out a sub. ofc 1% of music out there goes really low...but my towers sound just fine without a sub and play over 100db. I only have some 4ohm maggie lrs which I can compare to bookshelves...they get to maybe 90db w/out subs.
Power: Marantz sr7008, NAD C 275Bee x 2, Video: Oppo 103, Samsung 75un6300 LG oled c9 77
Speakers: Focal aria 948, Focal cc900, Klipsch synergy KSF 10.5, Magnepan LRS, Audioengine A2+
Subs: Rythmik FV25HP, Rythmik FV15HP, Velodyne HGS 12, Velodyne VA1512