I was always amazed when I got my Macintosh amps $100,000 and I could watch the meters. Most times I am listening at half of watt. When I really wanna listen it’s pushing 6 W the biggest transient I’ve ever seen made the meter go up to approximately 600 W. I also asked myself the same question.
Hooked up an old realistic power meter
Not sure if anyone remembers the Realistic APM-300 and I've had one from years ago and decided to hook it back up for fun. According to it, for most music and volume I listen to, it says I'm using barely a watt.
My speakers are 87db for one watt, amp pushes 225. My sounds level meter confirms the approx. 88 decibels I listen to and I did crank it up to around 90+ decibels and was still only using a few watts.
For some reason I though I would be using way more power than that and wonder why if everything is correct, why I need such a big amp?