JBL is absolutely killing this part of the market right now. I was never much of a JBL fan (the original L-100s were magnificently built but horrible sounding) until I heard the 4367 and S3900. Where Klipsch are nasal, harsh and have no low bass, these JBL's are neutral, dynamic and easily handle bass below 40 Hz. (Check out Klaus Voorman's unwinding his Low E string bass solo on Nilson's 'Jump Into the Fire ' or the sub-bass synth line on Stevie Wonder's 'I Believe When I Fall in Love', for true low bass power, then Pat Metheny and Charlie Haden 'Beyond the Missouri Sky' for pitch definition and bass detail. My jaw truly dropped.
Very few companies have the resources to develop, test, and build their own drivers. JBL's new dual voice coil and diaphragm designs, as well as their mastery of horn design, are simply beyond the reach of their competition.