Eminent Technology LFT-8b in Harry's system

Yes, the "a" update addressed issues with the ribbon tweeter's x/o (but not the tweeter itself), the "b" the 8" dynamic woofer.. You’ll notice that the LFT (Linear Field Transducer) magnetic-planar driver itself---which handles frequencies 180Hz through 10kHz, with no cross-over---has remained unchanged for over 30 years!

BTW, Harry Weisfeld now has Apollo 12 loudspeakers in his home in his reference system. Apollos are an AMT based line array.

With the Covid stay at home order in MI I decided to play around with the .6MH inductor.  I tried the new Jantzen copper foil in wax 14 gauge, which is all the rave.  Sadly, it thinned out the mids with maybe a slight increase in detail.....btw I hooked them up in both directions and they were worse than Bruce's stock 18 gauge magnetic wire air cores which are very good. I debated on ordering the 12 gauge copper foil in wax but decided to go with the Erse XQ 14 gauge perfect lay air coiled inductors.  I'm glad I did as the moment I hit play the mids sounded rich and full like a good tube amp.  The detail was all there and so were the highs.  I did A/B Bruce's inductors and easily identified the Erse's every time.....by the fat juicy midrange.  If you have a large room and are looking for more meat in the midrange than the Erse's are the ticket.   Funny how the change in wire gauge(DCR) can make such a big difference in the mids.  I think the inductor switch is just as significant as changing the 470uf and 4.7uf cap.        

Great thread !!!!

Thanks @brucefrederick. I myself am considering sending the LFT-8b x/o schematic to Danny Richie at GR Research, seeing what he recommends as an upgrade. One can send him a loudspeaker for a free complete evaluation (he measures the speaker, including spectral decay---aka waterfall plot, phase relationship between drivers, frequency response, both on-axis and off, etc.) but the ET doesn’t require that, just upgraded x/o parts.