I was never impressed by the HPM except for sweet-ish treble. Ok sounding midfi. Overrated "vintage" speaker. I have owned the JBL 4312A (bad imaging, bass rolloff at 60hz) L80t and L100t.

L100t/L80t
The strong points: The aquaplas midrange was very detailed and transparent.
The bass was tight, and controlled. Extended treble. Very strong into the 30's.

The bad points: The Ti tweeter sounded AWFUL unless you have no-kidding quality solid state or tube front end. The bass sounded boxy unless carefully positioned. The speaker REALLY needed a STRONG 200wpc + to shine.

IIRC, the crossover used mylar caps or electrolytics with mylar bypasses. I'd swap out all equal value metallized polypropelene.

JBL never made a tweeter that I liked, certainly not as praiseworthy as what Axiom is using now.

Last edited by Scottinwa; 08/20/14 05:11 PM.
Great Speakers start with great engineers.