Well, downsizing when stuff is exploding around you, may not be your best answer.
Also a single twelve might have a thermal rating as high as 300 watts but I would be interested to hear what its maximum displacement limited rating might be at say 50 HZ.
Sounds like you had better have a chat with someone about a
Fearful 12/6 at least then you can get a bit back with the horrifyingly long cone excursion of the Eminence 3012lf.
