A very useful concept or idea put forward by Leoprello. I will explain with an example.

Anthem MCA 225, if you read the manual, max power output single channel driven is 550 watts @ 2 ohms. If we consider both channels driven simultaneously this measure is lower, namely, 370 watts @ 2 ohms.

In my medium sized room i listen at -26db, Max volume is 7 db. If we consider the net reduction in volume in db is 33 db. Then power output of power amp is halved 11 times. 33/ 3 = 11.

In stereo watts this is 360, 180, 90, 45, 22.5, 11.25, 5.5, 2.75, 1.4, 0.8, 0.4 and finally 0.2 watts at -26 db

7, 4, 1, -2, -5, -8, -11, -14, -17, -20, -23, - 26db.

0.1 watts at 4 ohms. This is all the power i need from MCA 225 to listen at moderate intensity or 96 - 26 = 70db in my medium sized room.

A very surprising conclusion if my calculation is accurate. What counts is quality watts not quantity for Classic ELS 9. A true 30 watts RMS @ 8 ohms class A amp should be more than adequate.