Probably many or most of the models mentioned in this thread about high efficiency speakers, although the power capability of your MA1's may be overkill for some of them.
Coincident and Devore would undoubtedly be good choices to consider, as would Daedalus. The Daedalus Ulysses, which I own, are nominally only 6 ohms, but are a very benign 6 ohms in terms of the flatness of their impedance vs. frequency curve, and also, I'm fairly certain, in terms of avoidance of significantly capacitive phase angles, especially with the all-poly crossover option that is offered. See the comments near the end of that thread by Jazdoc, Atmasphere, and others.
Regards,
-- Al
Coincident and Devore would undoubtedly be good choices to consider, as would Daedalus. The Daedalus Ulysses, which I own, are nominally only 6 ohms, but are a very benign 6 ohms in terms of the flatness of their impedance vs. frequency curve, and also, I'm fairly certain, in terms of avoidance of significantly capacitive phase angles, especially with the all-poly crossover option that is offered. See the comments near the end of that thread by Jazdoc, Atmasphere, and others.
Regards,
-- Al