Different frequencies consume different power so "twice as loud" would be frequency dependent in many cases. Paying for an additional 50 watts will improve low frequency performance -- you may not hear it louder but you will hear it cleaner with respect to transients and lower distortion from better controlling the woofer. It gets integrated into the music a little better.
Perception and Watts: Doubling of power
There's a curious rule of thumb, which to my ears seems mostly true:
- To double the perceived volume, you must output 10x more power.
10x power = 10 dB by the way. We've read this as we were buying amps and trying to decide between 100w/channel and 150w/channel. We are told, repeatedly that 50 W difference isn't really that much.
On more than one occasion I've tested this and found it's pretty much spot on. Here's my question:
How can any of us really tell what half as loud, or twice as loud is?
I mean, think about this for a bit. I cannot tell half as bright, or twice as bright, but it seems I actually CAN tell what half as loud is. How does this even begin to work in the ear/brain mechanism?? 😁