Can someone explain db sensitivity?

My attempt to answer the original question "What it means and what is considered good? ":

From what I have seen and been told, speakers rated at 90db or so are considered to be of "average" sensitivity, perhaps of what's on the market right now. Speakers rated below 87db are considered "below average", and speakers rated above 93db are considered "above average". These are rough approximates of course.

From my listening experience, it seems that "highly efficient" speakers (above 96db) tend towards a brighter, more in-your-face sound. Klipsch, Cerwin, and some horns come to mind.

Bottom line though, IMO, the "db rating" has absolutely nothing to do with how good a speaker sounds, if the amplifier is up to the task. (2w amp on 80db rated speakers would sound bad). Having said that, I'm a fan of single ended, so I seek out speakers rated 93db or above, and more importantly, speakers that have a relatively flat impedence curve (which I think is actually more important in general).

These responses have helped me out in my quest to understand db and speakers.

Thanks,

Keith

I thought a 6dB difference is perceived as "doubly" loud
(4x power), not 10 dB. Someone clarify this? Isn't it a surface area, and therefore geometric (squaring) function for loudness, and not a logarithmic one?
Ern