Ineed some help with a simple math equation

Also important to understand how they eat power. Are they low impedance ? Difficult to drive due to high phase angle or low Z in the bass?

You may indeed need a very solid amp, but not necessarily need all those rated watts at 8 ohms.

Best,

E

Better measurements IMHO are distortion and noise in the actual usable range. If you have spec sheets, look at the THD+N in the 30-100 W range.

However, inefficient speakers are less sensitive to noise, and many doubt we can hear anything below 0.5%, so absolute numbers below that may e meaningless.

Best,

E