One of the problems with the older 3A MM’s is the soft dome tweeter sounds a bit wooly. This may be attributed to an inferior dome material or perhaps the 5.18uf Russian military capacitor used in the high pass crossover. A friend of mine is currently retrofitting a new pair of Morel Elite ET-338 tweeters into his De Capo i speakers. The big green Russian metal can capacitor is being replaced by an equivalent value Miflex copper foil capacitor. This should clean up the sound quite a bit. The hand coated Acuflex dome Morel tweeters from Morel sound amazing and are a tad less hot sounding than the Eminence ASD1001 compression drivers used in my Zu Omen DWII speakers. If Morel made a 97db acuflex dome tweeter, it would immediately be retrofitted into my Zu DWII’s. With regards to the impedance mismatch between Pass XA25 and the Omen DWII’s, Zu provides a guide for selecting snubber resistors to reduce any impedance mismatch. Gauging from the chart provided at the link below, perhaps a 20 to 22ohm pair of loading resistors would level up the impedance to match the Pass XA25 amplifiers 8 ohm output impedance to the 14ohm charcterisitc impedance of the Omen DWII’s. You can always call Gerrit or Sean at Zu. They are always helpful in answering any questions you may have. They are great ambassadors to this hobby!
https://www.zuaudio.com/diy/loading10r
https://www.zuaudio.com/diy/loading10r