My gripe with most speakers is that they are just unable to even acknowledge the presence of some bass notes. I use a audio spectrum analyser between my DAC and my power amp in order to track the audio excursions on the analyser display versus the speaker cone excursions. I have a wide range of tracks that clearly indicate the presence of sub bass, but are impossible to detect with anything other than a subwoofer. In my mind, that's both a loss in quality and quantity of the bass when 'ordinary' speakers can't even register those missing frequencies.