I am puzzled. No, really. I know you find it hard to believe that we sacerdotes of the golden-eared persuasion could ever be perplexed, but I have been pondering the imponderables of ports. Ever since the classic work of Richard Small and Neville Thiele in the early '70s showed how the low-frequency response of any box loudspeaker can be modeled as an electrical high-pass filter of some kind, with the relevant equations and data made available to all, there would seem to be very little reason why all loudspeakers with the same extension should not sound alike (or at least very similar) below 100Hz. Yet after reviewing 20 dynamic loudspeakers (and using 24) in the same room over the last seven months, I am led to the conclusion that speakers vary as much in the quality of their mid-to-upper bass as they do in any other region. A few are dry, more are exaggerated in this region; some are detailed and "fast," most are blurred, with the upper bass "slow" (by which I mean that the weight of bass tone seems to lag behind the leading edges of the sound).