2. misc-audio
  3. 181369-20253

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?? 😁

erik_squires

Showing 1 response by petg60

petg60
1,486 posts
 

10db should be perceived as double loud by most people, so to understand double loud you would need a 500w amp instead of a 50w one on same speaker. On the other hand our ears are not measuring equipment, take some time to adjust and have self protection that would change how some things sound in loud volumes.

My preamp increases +3db on every 6 steps (0,5 a step), ha!

 

More to discover