Perception and Watts: Doubling of power

Erik:

The early NAD PE's used class G.

I demo'd a few of those integrated amps and SQ improved, IMO, when the Power Envelope circuitry was defeated.

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

I had a Carver MXR-130 hooked up to single driver speakers (Stephens 80FR) and the meters showed them to be pulling quite a bit of power on musical peaks.

There are two meter settings (low/high) and it only showed up on one of the settings (forget which).

This said, I do not notice clipping/compression when running them with my 3 watt 2A3 amps, but I doubt that I ever listen louder than 80 dB (probably much lower, but with unknown peak levels).

DeKay

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.

Here's a blurb on meters.

I recall a few vintage pieces with fast/slow meter settings, but the Carver switch is marked low/high.

The Carver has not been used for @ least 10 years (afraid to power it on).

http://www.cordellaudio.com/instrumentation/power_level_meter.shtml

DeKay

How can any of us really tell what half as loud, or twice as loud is?

Using music as a test signal for determining half or twice loudness is indeed difficult. Music varies in pitch and loudness and so is a moving target. The bel scale was developed by Bell Labs using steady tones on multiple test subjects and determining an average estimation of half or twice as loud. The difference in acoustic pressure called a bel. Decibel, of course being 1/10 of a bel. So a bel is what the average human perceives as twice of half as loud.

The actual acoustic pressure between the threshold of hearing and the threshold of pain is more than a million to one. The human ear/brain compresses this range in a logarithmic manor so as to be manageable. This is why the objective acoustic power must be increased by 10x to be perceived as twice as loud.

To answer the original question: there is generally no reason for us to worry about what is half of twice as loud. But, it is good to understand that a 200 W amp will only play 3db (21.9%) louder before clipping than a 100 W amp.  

I believe a 3db increase in volume is perceived as twice as loud, not 10x power....that is what I’ve always read...anyhow..

https://www.logison.com/blog-article_/17588/blog-entry-19256/sometimes-change-isntgood#:~:text=A%203%20dB%20change%20yields,a%2023%25%20increase%20in%20loudness.