Watts! How many do we need?

Peaks are between 75 and 80db. I’m sitting and measuring about 8 feet from the speakers which are 7 feet apart. They are almost 3 feet from front wall and are 5 feet from side walls. Plenty of opportunities for sound absorption. The room is 17 x 15 and is carpeted and is not what I would call a live room as it has furniture as well. The peaks are as loud as I would want and doubling the loudness would apparently require 2 watts. When would I ever need 10 watts let alone 150? BTW these peaks I hear are produced effortlessly with a balanced presentation. No instruments or frequencies are emphasized. It’s a smooth delivery. 

The 1.5 watts of “audio magic” of the 45 tubes is plenty for me. My backloaded horns are 102 db efficient. Korneff integrated amp with Emission Labs 45 wire mesh tubes. Although I must admit that I cheat. With organ music I turn on a Velodyne 18GS subwoofer that has a built in 1500 watt solid state amp. Go figure…

I doubt those meters are able to measure actual peak power, it gets difficult to measure when a speaker is involved. 

The meters found on most amps are very rarely calibrated, and more often mislead rather inform.

Let’s assume the meters are not very accurate. How much off are they? By a factor of 10 so 10 watts peak? Or by a factor of 20 so 20 watts peak? And then we make the sound twice as loud (+3db). Now 20 or 40 watts.  Sill far below the amount of watts modern amps are offering.