Hello Carlos,
If I may suggest to you - I have published an article on the topic [its a bit simplify things, so I am sorry in advance...] where I use actual measurements of British engineer Keith Howard of the actual (peak) power consumed by difficult to drive speakers...during their reproduction of music and not on the test bench (what a revolutionary idea !):
http://www.enjoythemusic.com/magazine/manufacture/0708/index.html
I actually believe that real measure of POWER in power amplifier is in its headroom which is characterized not only by the peak current and peak voltage but also their duration and IMO, most importantly the level (and composition ) of distortions created by the amplifier.
So to answer your question you must know the power hunger of your speaker, room size, selected music and distance between speaker and listening chair...
Of course, for musical enjoyment (unless its hard rock) we need many more attributes which are beyond the questions raised in this thread.
All The Best
Simon
If I may suggest to you - I have published an article on the topic [its a bit simplify things, so I am sorry in advance...] where I use actual measurements of British engineer Keith Howard of the actual (peak) power consumed by difficult to drive speakers...during their reproduction of music and not on the test bench (what a revolutionary idea !):
http://www.enjoythemusic.com/magazine/manufacture/0708/index.html
I actually believe that real measure of POWER in power amplifier is in its headroom which is characterized not only by the peak current and peak voltage but also their duration and IMO, most importantly the level (and composition ) of distortions created by the amplifier.
So to answer your question you must know the power hunger of your speaker, room size, selected music and distance between speaker and listening chair...
Of course, for musical enjoyment (unless its hard rock) we need many more attributes which are beyond the questions raised in this thread.
All The Best
Simon