vair68robert - I susepect it's they guy who makes aftermarket 'fixes' for various speakers. when I spoke with him a few years ago he said his units 'fixed known abberations in the Thiel's upper midrange'. Rob Gillum bought one to measure and said he was reducing amplitude across the upper midrange and introducing phase-shift. Parts quality was significantly below Thiel's standards. These units are 'pre-crossovers', not replacements. They pre-shape the signal before it goes to the internal crossover.
Again I'm speculating what's up, could be something else.
