How many watts do you really need?

its all about headroom.  

@polkalover

Yea sir, it is all about headroom and the power to EXPAND THE SOUND without KILLING THE AMPLIFIER when using it to PUSH POWER HUNGRY SPEAKERS.

Good day and Peace to All

Dave Wilson’s original WHOW woofer (back in 1986) had a 15" driver and Dave used Rowland Research 300W amplifiers for it.

Also, as others as pointed out, power in reserve is a good thing. If, for example, one is listening to Wagner’s Der Rings des Nibelungen, a soprano going all-out could use every bit of a 600 watt amp’s power when Brunnhilde (Birgit Nilsson or Kirsten Flagstad) is singing. So, for the really big moments, 300 watts is a good power rating, but 600 watts, for that genre of music, would not be wasted.

For typical pop/rock/jazz music, a good  50-100 watt amp with good power supplies will suffice.

@polkalover 

"its all about headroom."

A good 5 watts per channel amplifier, efficient speakers in an average sized room, all the headroom you'll ever need.

Even if an amp is ONLY in Class A up to 40 wpc, that is so much power for ANY speaker that it will be playing at such a high volume level there is no way anyone can hear the subtle difference between Class A and Class AB operation; your own ears will be employing muscles to restrict motion of moving parts to protect the ears.

I personally favor amps that prioritize operation at less than one watt.  My 5 wpc amp has plenty of reserve for my purposes.