Shown are the step responses, measured in the nearfield, of the Wilson Alex's lower midrange unit (solid trace) and and upper midrange unit (dotted trace). Both were taken with a 1kHz bandwidth, which is why the upper-midrange step is smaller than the lower midrange step. (It rolls in at a higher frequency than the lower unit.) Contrary what I originally wrote in the review, the upper-midrange unit is connected in inverted acoustic polarity.