Hands down the best bass I've heard from a panel speaker was from a pair of Sound Labs, followed closely by a pair of Apogee Divas. Admittedly, there was a + 6-9 DB peak centered around the 40 HZ region of the Soundlabs, but it was tight, tight, and did I say tight, which made the presentation quite visceral without mucking up the mid or upper bass. The Divas had noticably more grunt down under 30 HZ but lacked the sense of bass to midbass slam that the Soundlab's bump brought to the table. This made the Divas more menacing...in a good way though.
That being said, I've gotten truly excellent results using sealed subwoofers with system Q's ~.6. Normally, such a low Q would result in a rather lean and dry low end, but I just juice it up a bit (+4-6 DB)in the 20-40 HZ octave and actively cross it over to the bass panels of my Apogees at 70 hz (and yes, I do cut the lower octave out of the Apogee's bass panel). The result is, in a word, thrilling. In two words, "shock & awe".
