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Topic: Audible symptoms of amplifier clipping (Read 52249 times) previous topic - next topic
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Audible symptoms of amplifier clipping

Reply #100 –
Quote from: Rich B on
It's people like you who piss me off the most. You're a fucking arrogant asshole who thinks his answer is the only valid answer.


Among rational people personal attacks like that are almost worthy of framing and putting on the wall. Trouble is, people who say things like that are like toilet paper - use once and flush!

Quote
*To add, I have been more than respectful in the past. You are the one who thinks I'm too dumb to comprehend anything. You and others put me down on several occasions.


Rich, if you could just show a real world example where you actually comprehended anything of significance. I've challenged you to show evidence of this several times and each and every time you run away.

I think one of the problems is that the very idea of reliable evidence has escaped you, never to return.

Audible symptoms of amplifier clipping

Reply #101 –
Quote from: Arnold B. Krueger on
Quote from: Rich B on
It's people like you who piss me off the most. You're a fucking arrogant asshole who thinks his answer is the only valid answer.


Among rational people personal attacks like that are almost worthy of framing and putting on the wall. Trouble is, people who say things like that are like toilet paper - use once and flush!


Yeah, because you convinced yourself that you're rational, and wow is me, you believe in a supernatural deity. Rational my ass.

Quote
Rich, if you could just show a real world example where you actually comprehended anything of significance. I've challenged you to show evidence of this several times and each and every time you run away.


I don't need to prove anything to you. I don't owe you anything. You belittle people nearly all the time, that's what you're good at. Your posts over at usenet are an excellent primer.

I may not know everything that has been posted, but I know somethings. I don't pretend to be an expert, and I don't pretend that my answers are absolute. You think you know it all.

Audible symptoms of amplifier clipping

Reply #102 –
Quote from: Rich B on
Quote from: Arnold B. Krueger on
Quote from: Rich B on
It's people like you who piss me off the most. You're a fucking arrogant asshole who thinks his answer is the only valid answer.


Among rational people personal attacks like that are almost worthy of framing and putting on the wall. Trouble is, people who say things like that are like toilet paper - use once and flush!


Yeah, because you convinced yourself that you're rational, and wow is me, you believe in a supernatural deity. Rational my ass.


I have convinced myself that I am 100% rational?

In what alternative universe was that? ;-)

I know that rational thinking is a good trick for human beings to do reliably and far from being how they operate most of the time,  myself included.

If I were rational all of the time or even just most of the time why would I need to do DBTs?

One of my operational assumptions is that I'm making irrational decisions early and often, every day.

As usual Rich, you make up Phactz in your little mind and then entertain the world by posting them in public places.

For the record, being 100% rational about even a narrow little area like audio is beyond me, or anybody else that I know.

Audible symptoms of amplifier clipping

Reply #103 –
Quote from: Rich B on
This is what is so confusing about these subjects.

Expert 1 chimes in and says that it's not the distortion, it's the excess power that does the damage. Expert 2 chimes in and says that the added distortion can result in speaker damage.

Expert 3 chimes in and says that the added distortion together with excess power does the damage, but depending on the conditions, may be a mix of the two.

Expert 4 (Jneutron) who is Arnolds biggest nightmare opponent has a completely different argument and I can't even begin to understand it, but it's a lot more technical than any of the explanations provided thus far.



Jneutron, like Amir, will spend pages and pages posting about cases that eventually are admitted to be typically inaudible.  He's happy to go way,way down the rabbit hole.

Audible symptoms of amplifier clipping

Reply #104 –
Quote from: krabapple on
Jneutron, like Amir

No. John knows what he's talking about and is not stricken with any audiophile disorder that I'm aware of.
Please, no.
Loudspeaker manufacturer

Audible symptoms of amplifier clipping

Reply #105 –
Quote from: Arnold B. Krueger on
I have that paper right here before me, and the above interpretation of it seems to tax  my imagination:

"I found the newer and better sounding amplifiers (including amplifiers with soft clipping circuits) had an even
greater occurrence of blown tweeters than amplifiers with lower power. And, amplifiers with higher power
were having fewer incidences of blown tweeters.


I don't have access to this paper. But does anyone have real data regarding how often tweeters blow wrt to the "headroom" (for lack of a better word) of the amp?
Or is everyone just operating on a hunch created by endless repetition of the "clipping causes harmonic distortion and thus a disproportional increase in power sent to the tweeter" dogma?

Audible symptoms of amplifier clipping

Reply #106 –
Ok, I'll admit I don't peruse every RichB fishing trip, so I just saw this:

Quote from: xnor on
Well, a speaker dipping down to 3 ohms (sometimes even 2 ohms) in the bass area and a 45° phase angle can mean serious trouble for some amplifiers.


And you were asking me why I was posting impedance graphs in the "biamping AVR" thread?
WTH??
Loudspeaker manufacturer

Audible symptoms of amplifier clipping

Reply #108 –
Quote from: ajinfla on
Quote from: krabapple on
Jneutron, like Amir

No. John knows what he's talking about and is not stricken with any audiophile disorder that I'm aware of.
Please, no.



Sorry, I'd like to agree, and mostly do (the 'knows what he's talking about' part), but I've seen him go down exactly the sort of long, deep, rabbithole I've mentioned, complete with '...but it's unlikely anyone would ever hear it' sad trombone punchline.


And please don't make me go look up his theories on audibility of spatial localization due to cable difference.

Audible symptoms of amplifier clipping

Reply #109 –
Jneutron is the only poster on AVS who made Arnold look like he was a little clueless. I don't know if he's a rocket scientist or what, but he's probably the most knowledgeable EE on AVS.

Plus he knows how to debate.

Audible symptoms of amplifier clipping

Reply #110 –
Quote from: ajinfla on
Quote from: xnor on
Well, a speaker dipping down to 3 ohms (sometimes even 2 ohms) in the bass area and a 45° phase angle can mean serious trouble for some amplifiers.


And you were asking me why I was posting impedance graphs in the "biamping AVR" thread?
WTH??

So, what fallacious conclusions do you draw here that demand a "WTH"? I asked you a specific question that you evade(d) to this day.

You don't fix a bad speaker design and bad amplifier combination by adding another one of those bad amps... Only a fool would do that, heh.

Instead, you get a better designed speaker or amp.
"I hear it when I see it."

Audible symptoms of amplifier clipping

Reply #111 –
Quote from: krabapple on
Jneutron, like Amir, will spend pages and pages posting about cases that eventually are admitted to be typically inaudible.  He's happy to go way,way down the rabbit hole.


Agreed. Every forum seems to have at least one person who pulls this shtick.

They tend to be very impressive to the poorly informed and naive.

Audible symptoms of amplifier clipping

Reply #112 –
Quote from: xnor on
Well, a speaker dipping down to 3 ohms (sometimes even 2 ohms) in the bass area and a 45° phase angle can mean serious trouble for some amplifiers.

Now if all evidence you've got is some "vague feeling that the amp doesn't provide enough power" or something of that sort ... nobody can tell what's going on. Could be anything from imagination/bias to slight clipping.



The physics of both vented and sealed box speakers tend to position a region of minimal phase shift (as little as zero degrees) around the frequency where the impedance is minimized.

Stereophile Dynaudio Excite (vented and sealed) Speaker Review



Fig.1 Dynaudio Excite X12, electrical impedance (solid) and phase (dashed) with port open (2 ohms/vertical div.).

Note that impedance of this vented box speaker is minimized at 200 Hz, and which point the phase angle of impedance is zero degrees.



Fig.2 Dynaudio Excite X12, electrical impedance (solid) and phase (dashed) with port closed (2 ohms/vertical div.).

Note that impedance of this sealed box speaker is minimized at 200 Hz, and which point the phase angle of impedance is zero degrees.

Audible symptoms of amplifier clipping

Reply #113 –
[from Rane, limiter sellers]
Quote from: Arnold B. Krueger on
And, amplifiers with higher power were having fewer incidences of blown tweeters. This appeared to reinforce the theory that tweeter blowouts were occurring because of clipping. One thing was clear, when clipping occurred, tweeters blew. It takes a lot more than this to cause major failure 8o what's happening?  Compression is what's happening [3].

Now we turn up the amplifier to clip the signal (3dB overdrive- See Fig'3). Notice that only the Iow frequency burst portion of the waveform clips but the high frequency portion increases in level. The clipping, of course, produces harmonics but not nearly as much as the square waves discussed earlier. The amplitude of the high frequencies went up by 3dB in relation to the low frequency fundamental. "  ..and so on..


So tweeters fail, right at that point of sustained clipping, whereas stronger amps at the same level don't fry them, yet it has nothing to do with the weaker amp being overdriven? Riiiiiiiiight.

So there's some, let's say "condition" which happens which causes the amplifer to modify its normal clean signal output [in his view the change is compression, but what it is exactly doesn't really matter to a consumer blowing their tweeters] which then damages the tweeters. Hmm. if only there was a way to keep the amplifier from entering this changed state so its output stayed clean at that same level. I wonder if that would add a modicum of tweeter protection, at least for that particular volume setting, with normal, dynamically changing music?.. 

What was it Rane said? Oh yeah:
Quote
And, amplifiers with higher power were having fewer incidences of blown tweeters.


Yes, and limiters would be one way to go too, probably the best and safest, but it is basically having a nanny which refuses to allow you to crank it up the way you like it. [And I have nothing against Rane, BTW].

Audible symptoms of amplifier clipping

Reply #114 –
Quote from: Gecko on
But does anyone have real data regarding how often tweeters blow wrt to the "headroom" (for lack of a better word) of the amp?


You can refer to it as "reserve power" instead of "headroom".

JBL, a very big company, has been making both professional and consumer speakers since 1946. I don't think they've conducted any formal surveys on speaker failures out there in the field, but they use rigorous IEC testing methodologies to make their power handling claims. Might you trust their conclusions? Have you read their white papers [see its summary] and FAQ pages on the numerous speaker failure modes? It is not just due to one thing, although here's one of them:

JBL: " If budget                  restraints or legacy equipment force you to use an amplifier                  with less power, extreme care should be taken to see that the                  amplifier is not driven into clipping. It may surprise you to                  learn that low power can result in damage to your speaker or                  system."

Audible symptoms of amplifier clipping

Reply #115 –
Sean Olive mentions using the limiter approach to prevent clipping, here:

"Consequently, the measured dynamic compressions shown below were largely related to the behavior of the electronic limiters in the Music Stations, designed to prevent the amplifier clipping, which could otherwise potentially damage the transducers."

Wait, what was it he said might potentially damage the speaker's transducers?

Audible symptoms of amplifier clipping

Reply #117 –
Quote from: mzil on
So tweeters fail, right at that point of sustained clipping, whereas stronger amps at the same level don't fry them, yet it has nothing to do with the weaker amp being overdriven? Riiiiiiiiight.


Excluded middle argument. Not all tweeter failures are the same.

Even at the mechanical level some tweeters fail due to mechanical fracturing of the voice coil lead wires, and others fail due to literal cooking of the enamel and former that holds the voice coil into a helix.

One of the problems with clipped sound is that it is muddy sound, so it does not reward the listener with the perception of greater clarity that he often obtains when he turns up the volume at lower levels.

A larger amplifier will address that loss as long as the tweeter itself can withstand the higher power levels without generating a lot of nonlinear distortion on its own.

The  matching of tweeter power handling to the size of the power amplifier in home audio systems varies all over the map because it is usually up to a non-technical person who tends to make more random choices than technical experts.

Rane's product marketplace is probably more heavily tipped towards audio professionals than say, Denon's.

Audible symptoms of amplifier clipping

Reply #118 –
Quote
Not all tweeter failures are the same
Gee, I seem to recall someone else made that point recently.

Quote from: mzil on
Have you read their white papers [see its summary] and FAQ pages on the numerous speaker failure modes? It is not just due to one thing, although here's one of them:  JBL: " If budget                  restraints or legacy equipment force you to use an amplifier                  with less power, extreme care should be taken to see that the                  amplifier is not driven into clipping. It may surprise you to                  learn that low power can result in damage to your speaker or                  system."

Audible symptoms of amplifier clipping

Reply #119 –
Quote from: mzil on
Quote
Not all tweeter failures are the same
Gee, I seem to recall someone else made that point recently.

Quote from: mzil on
Have you read their white papers [see its summary] and FAQ pages on the numerous speaker failure modes? It is not just due to one thing, although here's one of them:  JBL: " If budget                  restraints or legacy equipment force you to use an amplifier                  with less power, extreme care should be taken to see that the                  amplifier is not driven into clipping. It may surprise you to                  learn that low power can result in damage to your speaker or                  system."




JBL is a big company, and if you know how to work them from the inside you can find their various internal authorities singing somewhat different songs, especially over the >70 years that they have been big into speakers.

Audible symptoms of amplifier clipping

Reply #120 –
Quote from: Arnold B. Krueger on
Quote from: mzil on
Quote
Not all tweeter failures are the same
Gee, I seem to recall someone else made that point recently. 
Quote from: mzil on
Have you read their white papers [see its summary] and FAQ pages on the numerous speaker failure modes? It is not just due to one thing, although here's one of them:  JBL: " If budget                  restraints or legacy equipment force you to use an amplifier                  with less power, extreme care should be taken to see that the                  amplifier is not driven into clipping. It may surprise you to                  learn that low power can result in damage to your speaker or                  system."
  JBL is a big company, and if you know how to work them from the inside you can find their various internal authorities singing somewhat different songs, especially over the >70 years that they have been big into speakers.


And they prevent the better or at least contrasting "different song" version from being published by any of their employees anywhere for you to link us to, so others here reading your claim can verify this on their own, for what reason, exactly? Or is the reason itself also a secret and not published anywhere on the web?

Good to know you are aware of what their internal authorities actually think yet are forbidden to discuss publically though, thanks.

Audible symptoms of amplifier clipping

Reply #121 –
Quote from: mzil on
Quote from: Arnold B. Krueger on
Quote from: mzil on
Quote
Not all tweeter failures are the same
Gee, I seem to recall someone else made that point recently. 
Quote from: mzil on
Have you read their white papers [see its summary] and FAQ pages on the numerous speaker failure modes? It is not just due to one thing, although here's one of them:  JBL: " If budget                  restraints or legacy equipment force you to use an amplifier                  with less power, extreme care should be taken to see that the                  amplifier is not driven into clipping. It may surprise you to                  learn that low power can result in damage to your speaker or                  system."
  JBL is a big company, and if you know how to work them from the inside you can find their various internal authorities singing somewhat different songs, especially over the >70 years that they have been big into speakers.


And they prevent the better or at least contrasting "different song" version from being published by any of their employees anywhere for you to link us to, so others here reading your claim can verify this on their own, for what reason, exactly? Or is the reason itself also a secret and not published anywhere on the web?

Good to know you are aware of what their internal authorities actually think yet are forbidden to discuss publically though, thanks.


Anybody who has done tech work for or as part of a company of non trivial size knows that there are various opinions on various matters that are held by various people in the company. Technology tells you who has the best answers, and politics tells you whose word matters. ;-)

At JBL there are literally 100s of people with opinions on just about any audio matter. AFAIK there is no central clearing authority that controls which ones get published.

Audible symptoms of amplifier clipping

Reply #122 –
Quote from: mzil on
JBL, a very big company, has been making both professional and consumer speakers since 1946. I don't think they've conducted any formal surveys on speaker failures out there in the field, but they use rigorous IEC testing methodologies to make their power handling claims. Might you trust their conclusions? Have you read their white papers [see its summary] and FAQ pages on the numerous speaker failure modes? It is not just due to one thing, although here's one of them:

JBL: " If budget                  restraints or legacy equipment force you to use an amplifier                  with less power, extreme care should be taken to see that the                  amplifier is not driven into clipping. It may surprise you to                  learn that low power can result in damage to your speaker or                  system."

I've read the links. Might as well be that JBL, Rane and probably others have fallen victim to this forever-parroted myth (if it is one). Perhaps people who are aware of "get a bigger amp so you wont blow your speakers because of clipping" just don't crank their amps as much. Right now, all I see is conflicting opinions, where the link I provided earlier plausibly demonstrates that the power contributed by distortion products of clipping is small compared to the power without clipping. Whether that is actually negligible, I don't know. JBL on the other hand basically says: go buy one of our more expensive amps.

Audible symptoms of amplifier clipping

Reply #123 –
Quote
I don't know. JBL on the other hand basically says: go buy one of our more expensive amps.
Or...    Since JBL is mainly in the speaker business, they are saying, "It's OK to use a smaller speaker". 

I actually believe JBL is trying to give good-reasonable advice to their professional customers.
 

Audible symptoms of amplifier clipping

Reply #124 –
"Clipping is bad for loudspeakers because the amp may put out more power than you expect.
True. The real danger in clipping is that it could overpower the loudspeaker. Even an amp that may seem rated safely below the loudspeaker's power handling capacity might put out dangerous power levels if you are careless with allowing it to run into clipping.

In addition, severe clipping reduces the dynamic range because it quashes the peaks even as the average power in the output signal is elevated by excessive gain boost. Thus, there is often a temptation among inexperienced sound system operators to try to recapture some of the lost "punch" by pushing the levels even higher, which only makes the problem worse."

- Bob Lee
Technical Communications Developer
QSC Audio Products, LLC
Fellow, Audio Engineering Society

[Underlined text highlighted for emphasis by me, mzil.]