I have previously owned Martin Logan Prodigy biamped by Antique Sound Labs Hurricanes 200wpc and Crown K2 on the bass. In the beginning of 2009 I became interested in building a pair of Fostex 206 based back loaded horn. Not knowing what to expect, fired them up and since then never turned the Martin Logans on again. Next step I got Air Tight 300B amplifier as 8 watts were more then enough. The ASL Hurricanes were sounding too bright and 200w were overkill.

This Fostex 206 back loaded horn is the most transparent & detailed speakers with tightest bass I have ever heard. The midrange shout was initially a concern but mostly tamed by the 300Bs and later to a non-existent level using my Accuphase C-200V preamplifier's tone control.

Overall it was an eye opening experience. High efficientcy speakers and the magic of SET are in a different league compared to high powered SS amplifiers & giant in-efficient speakers IMHO.