Perception and Watts: Doubling of power

@audioguy85  I believe @hertzhead  has correctly explained the issue.

3 dB corresponds to 2x the voltage at the speaker terminals, but we do not actually hear it as twice as loud.  We hear it as a noticeable increase, but not twice.  You can try this yourself with an SPL meter.  Use a test tone and try increasing/decreasing by 3 dB. 

The early NAD PE's used class G.

Thanks for the correction, @dekay 

Do the meters on your Luxman register "fast" peaks?

Not a tall, I don't think of them as very twitchy.

The there’s amps that can supposedly “increase instantaneous power, for effortless reproduction of musical transients.” Don’t know the science behind this, but it sounds like a good thing…

@anotherbob - Marketing hype for a couple of different things some amps do. There were some like NAD / Proton (back in the day) which famously used 2 voltage rails in the amps. The high voltage had no staying power, but for short transients could deliver more than the low voltage rails could do. I think this was Class H.

Bob Carver’s amps did something like this, using a linear amp which would float among multiple voltage rails. The NAD/Hypex hybrids do this also.

A lot of this has to do with federal regulations about how you rate a power amplifier. To combat outrageously useless amplifier specs of the day the FTS imposed regulations about not only stating distortion and power together but also your amp must be preheated. The preheating required a lot more heat sinks to achieve the same wattage rating. As a result, some amplifiers may have significant more headroom than they may show in the power spec alone.

To be honest, music is never steady state and a lot of audiophiles with 300 Watt amps never go beyond 30, so there’s a lot to be said about right sizing an amp to your needs. .

@dekay So weird how well that works.

To clarify a little, 3 dB is a moderate amount of change in volume.  Perceptible but not close to being perceived as double the volume.

It is however 2x the power.

Here's a question, @johnnycamp5  - Lets say you play some music.  Can you turn it down by half?  Or can you turn it up to be twice as loud?  How do you know??

I mean, I can, and I think you can too!  but... how do we know what half is?

Lots of interesting discussion here, of course, but I really did just want to ask, how can we tell what twice as loud is?  I mean, I think I can, and it happens to match 10 dB.  WHY?  Our visual systems however seem very good at seeing twice the length or half the length, or finding the mid point on a line. Kind of weird that we also have a sense for half or twice as loud.

Hey @fuzztone , based on you asking questions like "Why do I care" on another thread, it may be helpful to remind you that this is a community driven site and not one you pay for.  If you find threads you are not interested in feel free to ignore them.

You might also want to take a look at the number of others who have participated in these threads and think "well, others are having fun so I should let them."  Just a thought.