For decades I used about 27 watts per channel. It was enough with efficient speakers for neighbors to complain.
But...that system just caved when confronted with more modern music with ridiculous bass levels. It was enough for Vivaldi...not enough for the Matrix soundtrack. My over 400 watts per channel is very economical compared to my old Pioneer rig and being Class D it probably uses less power on average at normal levels.
That being said...sometimes I like to rock very hard and 27 watts does not cut it. My new amp laughs at demanding bass notes. That being said, with efficient speakers ([email protected] [email protected]
meter) 100 watts per channel
run wide open will enable you to meet the neighbors and the police.
When all else fails...putting on a pair of Sennheiser HD600's will destroy most speaker/amp combos...and the room they are in. So many people forget how important the room is. I still do not have a correct one.
Almost no one does! Phones...the route taken by the very picky...and the most economical too!