One of the best I've owned was the ADS 1530, with an efficiency rating of 95 db. They could play loud, could handle 500 watts,and sounded great. They were Telarc's studio monitors for years, until they updated and went to Waveform Mach 7's. Their only drawback was their immense size, being 2" wide, 52" high, and weighing over 100 lbs. Sometimes I still wish I had them back. I'm currently using their 1590's, not quite as efficient as the 1530's, but only 12" wide towers.