The essence is the Borresen line uses a patented material in the drivers.
Lars Christensen gave a 6 minute explanation at RMAF one year that I videoed.
Read up on line for a more accurate explanation.
Borresen X3 at Axpona
I listened to these speakers at Axpona and thought they were amazing for the price..Very open,forward midrange. Any opinions out there on these? We listened to Jonny Cash and his voice was incredible.l would highly consider buying a pair of these for 11K