Ampdog
R.I.P. 23 June 2022
I was in two minds as to whether this should form an extension of the Kinosfronimos thread on 'Implications of underpowered Amplifier on Speakers'. Though that is a very informative thread, I finally decided that this topic is interesting enough in itself to stand separately without disrupting there (as I fear it is sure to do), and particularly in the light of a very persistent misconception which survived for decades now. That is that clipping of a signal by an underpowered amplifier can in itself generate enough (extra) harmonic power at frequencies not there before said clipping, to blow tweeters in particular.
It was for long an acceptable argument (also with me) to hold water, particularly when superficially looking at the logic.
Despite its logic it is untrue, as analysis of the factors involved will show. Plus an added bonus if you will, of the unexpected explanation of the origin of the idea, by someone who helped form it!
To keep matters brief and clear, I decided to refer readers to articles/posts elsewhere to save space; these are from experts, including graphs, which could hardly be bettered. ('A picture is worth a thousand words' and such . . .)
All the references are heavily copyright protected of which I would not like to run foul. I do quote the intro of the first reference, which I think is allowed to simply 'wet the appetite'. Further, I think it is fair to ask that readers go through (and understand!) all that is referenced before hazarding comments.
1. "Why do Tweeters blow when Amps distort". Copyright 2001 - Rod Elliott (ESP)
Hopefully I will be allowed to quote Mr Elliott's intro paragraph as stimulus:
"A vexing question, regularly asked and rarely answered properly - Why do Tweeters Blow when Amplifiers Distort? The answers are actually quite simple, but common misconception is that the distortion creates harmonics and the additional harmonic content destroys the tweeter.". Copyright: Rod Elliott.
2. Eye-opener! . "Clipping or too much Power" - Audiokarma. Copyright: Ken Kantor (EE), previously of AR and JBL loudspeaker manufacturers. [Go to page/screen 5 and scroll down to post #84 by Ken Kantor (the post number is given in fine print at the bottom right corner of each post.)]
Accompanying this in 'Audiokarma' are a number of other posts of interest on this subject. In addition, for those with enough interest/energy to investigate, there are several relevant threads in other forums. (Careful: It took this author >5 hours of reading through >300 posts in total to try and get a balanced picture - claims, counter-claims, beating-about-the-bush and occasionally plain 'strawmen', mostly with insufficient/total absence of any supporting science/evidence.)
Most of us do not have at our disposal enough instruments to check Mr Elliott's graphs. But knowing and having read his pronouncements over decades, I am confident of Mr. Elliott's prowess as an EE. His "ESP" site is well known and respected.
The eminent British mystery writer Dick Francis once said: "Entrenched beliefs cannot be altered by facts." Sadly, this writer is sceptical enough to reluctantly support that. But there are always exceptions!
Hopefully this was informative. If it could generate fresh interest in just one person, the purpose was served.
It was for long an acceptable argument (also with me) to hold water, particularly when superficially looking at the logic.
Despite its logic it is untrue, as analysis of the factors involved will show. Plus an added bonus if you will, of the unexpected explanation of the origin of the idea, by someone who helped form it!
To keep matters brief and clear, I decided to refer readers to articles/posts elsewhere to save space; these are from experts, including graphs, which could hardly be bettered. ('A picture is worth a thousand words' and such . . .)
All the references are heavily copyright protected of which I would not like to run foul. I do quote the intro of the first reference, which I think is allowed to simply 'wet the appetite'. Further, I think it is fair to ask that readers go through (and understand!) all that is referenced before hazarding comments.
1. "Why do Tweeters blow when Amps distort". Copyright 2001 - Rod Elliott (ESP)
Hopefully I will be allowed to quote Mr Elliott's intro paragraph as stimulus:
"A vexing question, regularly asked and rarely answered properly - Why do Tweeters Blow when Amplifiers Distort? The answers are actually quite simple, but common misconception is that the distortion creates harmonics and the additional harmonic content destroys the tweeter.". Copyright: Rod Elliott.
2. Eye-opener! . "Clipping or too much Power" - Audiokarma. Copyright: Ken Kantor (EE), previously of AR and JBL loudspeaker manufacturers. [Go to page/screen 5 and scroll down to post #84 by Ken Kantor (the post number is given in fine print at the bottom right corner of each post.)]
Accompanying this in 'Audiokarma' are a number of other posts of interest on this subject. In addition, for those with enough interest/energy to investigate, there are several relevant threads in other forums. (Careful: It took this author >5 hours of reading through >300 posts in total to try and get a balanced picture - claims, counter-claims, beating-about-the-bush and occasionally plain 'strawmen', mostly with insufficient/total absence of any supporting science/evidence.)
Most of us do not have at our disposal enough instruments to check Mr Elliott's graphs. But knowing and having read his pronouncements over decades, I am confident of Mr. Elliott's prowess as an EE. His "ESP" site is well known and respected.
The eminent British mystery writer Dick Francis once said: "Entrenched beliefs cannot be altered by facts." Sadly, this writer is sceptical enough to reluctantly support that. But there are always exceptions!
Hopefully this was informative. If it could generate fresh interest in just one person, the purpose was served.
