If you really want to boogie in a large room, you might want to consider and have access to the Classic Audio Reproductions line, you might want to give their T-1 a listen. If you fried the tweeters on your old speakers, you were probably driving the amp into clipping. The much higher efficiency of the Classic Audio line will require relatively little power to reach live spls, which in turn is likely to keep your amp from clipping. I've heard them in very large rooms at shows (maybe 40 x 40 or bigger) w amps that will deliver have much lower output than the JC-1s (of course they WERE tube watts). They sound fantastic and can reach very high spls.
Another possibility to consider would be a line-source speaker. They do not drop off as rapidly in volume w distance as a point source speaker. Pipedreams, Dali Megalines (maybe more of a quasi line-source) or Audience comes to mind.
Remember when trying to extrapolate from someone else's results, that a 30 x 30 room has almost 3x the volume of a 20 x 15 room. Maybe more if your large room has higher than normal ceilings.
Another possibility to consider would be a line-source speaker. They do not drop off as rapidly in volume w distance as a point source speaker. Pipedreams, Dali Megalines (maybe more of a quasi line-source) or Audience comes to mind.
Remember when trying to extrapolate from someone else's results, that a 30 x 30 room has almost 3x the volume of a 20 x 15 room. Maybe more if your large room has higher than normal ceilings.