Not merely my "take" Micah; simple principles of physics. Listening distance is the key.
Ok so simple principles of physics would go like this... Listening distance + desired decible output = AVR/external amp.
In other words for JohnK,
10 foot (listening distance) + 86 db's (desired decible output) = AVR (sufficient for the job).
for Micah,
16 foot (listening distance) + 120 db's (desired decible output) = external amp (necessary to achieve goal).
This is correct, yes? Personal preference for volume certainly comes into play in this equation. How loud you wish to play movies/music on your speakers is the biggest part of the equation when figuring out if you'll need external amplification. Room size and listening distance are also important, but it's the decible level you are trying to achieve that ultimately decides this debate.
The simple physics discribed demand more power to achieve higher db levels. If my Denon can achieve 120 db's in my room at my listening distance, then that number is in error in my example, and it should be higher. Because what ever the db level is that the Emotiva drives my M80's to, it's higher than the Denon is capable of. So what ever that number happens to be, replace 120 db's with it, and this will be my equation.
It really is simple physics after all.
