The M-909's were built with 2 8" drivers from Vifa (M21WJ-49), 1 5" mid-range from Vifa (C13MH-08), and 1 tweeter from vifa (D26TG-05). The speakers were rated to handle 100 watts of power. I have had my pair of M-909 since 1989. I use two Denon POA-6600 amps (360 watts each amp)to power them. The speakers can take a beating.