Clipped Amplifier Signals: What's correct and incorrect about this Video? - Page 3 - AVS Forum
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post #61 of 116 Old 08-08-2014, 09:20 PM
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Originally Posted by Garidy View Post
A pure AC square wave in and of itself, has nothing to do directly with driver failure - Nothing! The failure is merely a result of exceeding the sustainable thermal input level. Like all other waves, when it's clipped, will increase the rate at which the thermal limit is reached.

An AC square wave is not a DC equivalent! The square like wave that is often produced during heavy clipping is a hybrid AC/DC signal, it's not just one or the other. The percentage depends on how wide spread the clipping is. A Coulomb is a Coulomb, the delivery method doesn't change this fact. It is over Coulomb-ing, if you will, that kill's VC's.

So the absolutely correct answer to your question is: in the 1970's, just as today, VC's only burned from being over powered; therefore, if the VC's didn't burn, they weren't pushed past the edge of the thermal tolerances (Wattage vs. Time) of a given VC. There is no 'splaining' for Lucy or anyone else to do. It's just time for people to start learning and applying the most rudimentary understandings, of circuit design.

All this nonsense about fundamentals and harmonics, it's irrelevant, during heavy clipping, which is our context. All the signals get pushed to the limit of the Voltage rails. A Voltage and it's accompanying Coulombs, cannot distinguish between either of them. During heavy clipping many of them and some cases almost all of them (harmonics) are elevated to match the clipped Voltage of their respective fundamentals, only those at the fringe of the onset, partially escape (I have now repeatedly explained this). When an amplifier has no more Voltage to give, it has no more Voltage to give. When a waveform is being clipped, it's fundamental and harmonic signals get the maximum Voltage that a given amplifier is able to slew, in said condition of operation, the Voltage in this state, has become regulated to be more of a steady stated delivery of Coulombs, on, so on, and so on...

When a driver is in heavy clip, say better than 50% of the wave, heck let's even say 80% of the wave, the Wattage hasn't increased, like I read many state in here, but rather, it gets applied equally across the parentage of the waveform that is experience clipping. The perceived increase in loudness is due to the presence of more of the wavelength being amplified at the same amplitude, as apposed to being amplified as prescribed, in a dynamic relationship to each other. In other words, all of the energy within a waveform is being presented at the amplifiers maximum voltage, which also accounts for the tonal shift that occurs from the onset and throughout the progression of clipping. If your goal is to produce the highest SPL possible, use one tone and clip it against the rails and you will amplify almost every last transient, at the same amplitude (this will sound very poor). If your goal is musicality, stay miles away from even the slightest onset of clipping.
Pointless to discuss further. Look at amp tests. Find me one where fifty percent of the wave is clipped whatever you think that means. In the end folks who say clipping damages speakers just don't understand what they are saying.

if an actual square wave doesn't kill speakers, then an amp clipping at a point that it looks close to a square wave, which does not ever happen, does not kill speakers because of the harmonics added by the distortion. The speakers cannot see or feel or smell or taste whether the harmonics they receive are from the last amp in the chain or straight from the instrument being recorded.

I guess I failed to state the very painfully obvious so here it is. The added harmonics ARE the distortion. Total harmonic distortion measures the added harmonics. You cannot escape this even with a very fine wand from Ollivander. There is no magic. If it is distortion it adds harmonics. If it doesn't add harmonics it is not harmonic distortion. Nobody suggests that phase distortion kills speakers. A fella can imagine that distortion is a magical thing but it just is not. Dream on dude.

Btw there are a lot of people who have spent kilo bucks on 300B amps who fiercely believe their distortions are highly musical. And of course millions if guitarists and at least hundreds of thousands of keyboardists. Or maybe Elvis and the Beatles and Cream and Led Zep and Hendrix and the Allmans and Deep Purple and jimmy Smith and all those fools at Motown and Sun Studios and everybody who came after them is not musical.
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post #62 of 116 Old 08-08-2014, 11:34 PM
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Originally Posted by Garidy View Post
The square like wave that is often produced during heavy clipping is a hybrid AC/DC signal, it's not just one or the other.
Wrong. It's ALL AC.
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post #63 of 116 Old 08-08-2014, 11:51 PM - Thread Starter
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Originally Posted by A9X-308 View Post
Wrong. It's ALL AC.
Yes, actually you're correct, I misspoke. Thank you for quickly pointing that out.

It is a wave that is now delivered with a hybrid / cross of current deliveries, to a given VC, comprised of both alternating, non-alternating Voltages; with the latter transferring a greater amount of current, during it's presence, in place of alternating currents.

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post #64 of 116 Old 08-09-2014, 12:01 AM
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Originally Posted by Garidy View Post

It is a wave that is now delivered with a hybrid / cross of current deliveries, to a given VC, comprised of both alternating, non-alternating Voltages
There is no 'non-alternating voltage'. It's ALL AC. Study up Fourier.
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post #65 of 116 Old 08-09-2014, 12:50 AM - Thread Starter
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Originally Posted by JHAz View Post
Pointless to discuss further. Look at amp tests. Find me one where fifty percent of the wave is clipped whatever you think that means. In the end folks who say clipping damages speakers just don't understand what they are saying.

if an actual square wave doesn't kill speakers, then an amp clipping at a point that it looks close to a square wave, which does not ever happen, does not kill speakers because of the harmonics added by the distortion. The speakers cannot see or feel or smell or taste whether the harmonics they receive are from the last amp in the chain or straight from the instrument being recorded.

I guess I failed to state the very painfully obvious so here it is. The added harmonics ARE the distortion. Total harmonic distortion measures the added harmonics. You cannot escape this even with a very fine wand from Ollivander. There is no magic. If it is distortion it adds harmonics. If it doesn't add harmonics it is not harmonic distortion. Nobody suggests that phase distortion kills speakers. A fella can imagine that distortion is a magical thing but it just is not. Dream on dude.

Btw there are a lot of people who have spent kilo bucks on 300B amps who fiercely believe their distortions are highly musical. And of course millions if guitarists and at least hundreds of thousands of keyboardists. Or maybe Elvis and the Beatles and Cream and Led Zep and Hendrix and the Allmans and Deep Purple and jimmy Smith and all those fools at Motown and Sun Studios and everybody who came after them is not musical.
Without math to support your claims, I'm sorry, but I cannot be swayed. Much of what you have posted seem to have been composed in hast. It's clear that you haven't carefully read, and re-read every word that I have posted. Harmonics and Fundamentals are just signals, signals that all get pegged to the limit of the Voltage rails output, during their propagation within a clipped portion of the wave... I've said this over and over. Distortion is just another name / adjective to describe the qualities of a part of a waveform, a whole waveform, or even an envelop, etc.. It's just energy, it all gets the same treatment when it's in the throws of clipping, if you will.

We are still at step one:

A VC burns only from exceeding the thermal wattage tolerances. Wattage can be produced by either Pure AC energy delivery, Pure DC energy delivery or a mix of the two. AC and DC are not energies- just the delivery types for electrical energy. Think back to Edison end Tesla, they were both selling Power - Coulombs. They both charged by the Kilo-watt, or some such scale; however, one used DC to deliver their energy and the other used AC. So, to a VC, current is current - it's all just coulombs, DC or AC - just coulombs. When coulomb are directly applied to a circuit the voltage and current are locked in phase, in a steady state of delivery. Because the power delivery is absolutely pure (P) not reactive (Q), and non-varying, it can produce more work than AC of the same Voltage and load, if you will. Now, a VC can only handle so many coulombs, for a given period of time, before it will fail - thermal tolerance overrun. DC is able to transfer more current than an alternating current, of the same Voltage, for a given period. The divide between them is based on the frequency and phase angle of the AC carrier. It can be mathematically calculated. In any event, current applied directly, without any gaps, intervals, pauses etc., will heat up a VC faster than any delivery method that spreads the delivery out, over time, and who's power (P) isn't absolute, but rather determined by subtracting the reactive power Q, produced by the presence of inductance and capacitance (which produces phase angle errors). An equivalent AC Voltage will always contain less potential, to perform work, when all other factors being equal, such as load.

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Last edited by Garidy; 08-09-2014 at 01:37 AM.
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post #66 of 116 Old 08-09-2014, 01:16 AM
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Originally Posted by Garidy View Post

If you cannot bring the math...
I did, only I expressed it in English. The following makes the conundrum of the parts of the post I removed quite clear,

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Originally Posted by Garidy View Post
Crest factor calculations / formulas vary in accordance with the type of waveform.
No they don't. There is one equation for calculating the crest factor of any wave. The math says it should, and IME years of applying it shows that it applies very well to any wave:

http://en.wikipedia.org/wiki/Crest_factor

"
Crest factor is the peak amplitude of the waveform divided by the RMS value of the waveform:

C = (|x|{peak} / x{rms}).
"

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Originally Posted by Garidy View Post
During music, and especially during short incidents of clip, many wave forms are present. Your attempt to overlay a universal equation by means of suggesting that merely one, normalized waveform type is present, is contemptuous toward truth.

The above completely ignores the simple and obvious fact that the Crest Factor of varying waveforms itself varies.

What a concept!

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Originally Posted by Garidy View Post
Lastly, when an amplifier is in a wide state of clip, the crest factor is 0dB, because at a minimum the waveform is closer to that of a square wave then any other waveform (leaving aside DC for now, to make clear this one point) and all square waves have a crest factor of 0dB.
Finally, in the midst of confusion and errors, a true statement! Huzzah!

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But again, only when they're normalized...
False claim. If one understands the definition of Crest Factor one understands that it is in some sense, self-normalizing.

If the overall waveform is amplified or attenuated, both the Peak and RMS values increase or decrease proportionately, and their ratio which is AKA Crest Factor remains the same as long as the shape of the wave remains the same.


Hey, the post did get one thing right in the midst of a cascade of misunderstandings and misapprehensions. Thanks for that! ;-)
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post #67 of 116 Old 08-09-2014, 01:19 AM
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Any experimental data that you can link to where someone tested this hypothesis?
Too obvious to bother to test.
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post #68 of 116 Old 08-09-2014, 01:27 AM - Thread Starter
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There is no 'non-alternating voltage'. It's ALL AC. Study up Fourier.
No disagreement... a wave is a wave, truncated or not...

However, the nature of the current delivery is predicated by the shape of the waveform and the ability of all of the amplifying devices, within the signals chain, not to change the waveform geometries, prior to the onset of clipping. Once waveforms start to get pegged to the voltage rails, the voltage is no longer alternating for the whole length of the wave (yes, one can increase the magnification on a scope to see some fluctuation; however, if I was to run through the RMS for a given clipped portion, the Voltage spanning the clipped portion of the wave, would not typically vary by even a volt, but rather a portion of a volt, therefore making the voltage delivery decidedly constant, which is tantamount to DC deliveries; ultimately, these calculations would produce a higher RMS wattage, due to more of the waveform receiving the peaked voltage. So the presence of direct current deliveries within the waveform, do in fact increase the wattage input into a driver, therefore heating up the VC more rapidly, but not necessity past up to or past a drivers thermal limits. This wattage increase isn't due to an overall increase in on output Voltage, but is due to the harmonics being elevated to the same output voltage of their respective fundamental, and simply because more of the wave form is receiving the maximum voltage that the amplifier can slew, during it's railed state. I know that I am now repeating myself, with great frequency.). It's still a wave, coulombs are still being delivered via a frequency carriers; however, coulombs are also being delivered throughout the wavelength more directly, which more rapidly applies wattage to the VC, which in turn causes it to more rapidly reach it's thermal tolerance limit.

I'm not here to sell the idea that a clipped signal has become DC, or a square wave (at least not intentionally, thanks again for pointing out my clumsy error).

Thanks again

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post #69 of 116 Old 08-09-2014, 01:33 AM - Thread Starter
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Originally Posted by arnyk View Post
I did, only I expressed it in English. The following makes the conundrum of the parts of the post I removed quite clear,



No they don't. There is one equation for calculating the crest factor of any wave. The math says it should, and IME years of applying it shows that it applies very well to any wave:

http://en.wikipedia.org/wiki/Crest_factor

"
Crest factor is the peak amplitude of the waveform divided by the RMS value of the waveform:

C = (|x|{peak} / x{rms}).
"




The above completely ignores the simple and obvious fact that the Crest Factor of varying waveforms itself varies.

What a concept!



Finally, in the midst of confusion and errors, a true statement! Huzzah!



False claim. If one understands the definition of Crest Factor one understands that it is in some sense, self-normalizing.

If the overall waveform is amplified or attenuated, both the Peak and RMS values increase or decrease proportionately, and their ratio which is AKA Crest Factor remains the same as long as the shape of the wave remains the same.


Hey, the post did get one thing right in the midst of a cascade of misunderstandings and misapprehensions. Thanks for that! ;-)
Hey Arny thanks for your reply, it's 4:32 am where I am, so I got to call it at night/morning.

I will reply to you over the coarse of the weekend.

Good night, to all...

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post #70 of 116 Old 08-09-2014, 07:19 AM
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Originally Posted by JHAz View Post
If you had an amp that distorted with only odd harmonics and you could get it to issue odd harmonics at the right levels to mwke a square wave,the harmonics from distortion would be a litte less than 16 percent of total power. Look it up. All these things are well defined. What does that mean? Imagine what you want. Reality will be what it is.

Alternatively why didn't everybody's speakers melt in 1970 when the minimoog made square waves accessible to almost everyone? I musta spent an hour with the square wave in the store and I could never afford one. No speakers died, either from me or keith emersom or rick wakeman, although the minimoog gets way closer to a perfect square wave than any clipping amp. Got some splaining to do, Lucy.
Were you playing these square waves at full volume? How about half volume? At half volume you would be using about 1/20th (or much less) of the amps power, so if it was a 100wpc amp, you would be using about 5 watts (or again, much less) on a sine wave, and not much more on a square wave.

Heat kills speakers (and obviously physical damage will too), and I'm pretty sure everyone is arguing over semantics, as the term "over powering" is often mis-used and/or misinterpreted. Again, a 400w amp will not kill a 100w rated driver (assuming marketing wasn't involved heavily on either side) under normal use, even with electronic music with I don't care what shape waves being used. People are so scared to put their 100w rated speaker on a 110wpc home receiver because they just hear that they are going to "over power" their speakers, and that simply isn't true. The point isn't arguing over semantics, it's getting good information out there for real world use, not lab conditions with test tones that people don't listen to, let alone at full volume.

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post #71 of 116 Old 08-09-2014, 07:28 AM
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Too obvious to bother to test.
It clearly is not or we would not have these arguments.

So I ask more broadly, are there a set of tests where a sampling of speakers were used with a few power amps at differing power to see which can damage which speaker?

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post #72 of 116 Old 08-09-2014, 03:02 PM - Thread Starter
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Originally Posted by arnyk View Post
I did, only I expressed it in English. The following makes the conundrum of the parts of the post I removed quite clear,



No they don't. There is one equation for calculating the crest factor of any wave. The math says it should, and IME years of applying it shows that it applies very well to any wave:

http://en.wikipedia.org/wiki/Crest_factor

"
Crest factor is the peak amplitude of the waveform divided by the RMS value of the waveform:

C = (|x|{peak} / x{rms}).
"




The above completely ignores the simple and obvious fact that the Crest Factor of varying waveforms itself varies.

What a concept!



Finally, in the midst of confusion and errors, a true statement! Huzzah!



False claim. If one understands the definition of Crest Factor one understands that it is in some sense, self-normalizing.

If the overall waveform is amplified or attenuated, both the Peak and RMS values increase or decrease proportionately, and their ratio which is AKA Crest Factor remains the same as long as the shape of the wave remains the same.


Hey, the post did get one thing right in the midst of a cascade of misunderstandings and misapprehensions. Thanks for that! ;-)

Good day Arny,

I’m a little concerned that we’re needlessly miscommunicating with each other, which in turn is most likely confusing those desiring to learn from us. Perhaps we can help each other get on the same page, and others with us. I am quite certain that your knowledge and experience is greater than my own; however, at these current levels of discussion, my education and experience are more than sufficient. That doesn’t mean that as I revisit some of this stuff, that I my memories will be perfectly intact, or that I won’tmake a clumsy mistake or two along the way. I’d rather have you and others ofyour caliber, come alongside and work with me, to get the message/education straight, for those gaining their first exposures, etc.

I suspect that we are not as many degrees apart, as we appear to be to others, and potentially each other. I developed this belief as I was reading through your replies to me. What I discovered was more gamesmanship and miscommunication than anything else.

I offer the following Reponses to your cited conundrums; noting firstly, that I personally believe that you will be surprised, by how many contradictions you put forth, as I don’t think they were intentional, but the result of gamesmanship:

1. You start off by quoting a small part of my reply: “If you cannot bring the math”.You dropped the balance of the sentence, which is “then it makes it harder for either of us to guide one to correction.Leaving me only able to respond in kind (English).”

a. Your reply: “I did, only I expressed it inEnglish. The following makes the conundrum of the parts of the post I removedquite clear,”
i. Without math, nothing is clear in electrically!

b. Arny, without math, nothing is clear electrically, because we can’t see it, to properly verbalize it without math and related measurement devices, and graphing of the results.

c. Stating that math and English are interchangeableis a contradiction, to the truth.

d. I would also add that an intentional perversion of context is a pretense for diversion, and most probably subversion, etc. (gamesmanship).


2. Secondly, you quote the opening sentence of one of my paragraphs: “Crest factor calculations / formulas vary in accordance with the type of waveform.” Leaving my supporting text, for this statement behind (evidence, context and framework).

a. Your reply: “No they don't. There is one equation for calculating the crest factor of any wave. The math says it should, and IME years of applying it shows that it applies verywell to any wave:”

i. http://en.wikipedia.org/wiki/Crest_factor

ii. “Crest factor is the peak amplitude of thewaveform divided by the RMS value of the waveform: C = (|x|{peak} / x{rms}).”

b. Arny, in your reply you clearly stated: “No they don't.” And that there is only one equation for calculating the crest factor of any wave. Then you went on to evidence your position by citing IME, etc., and then posted a link to Wikipedia. The data in the link contradicts what you claimed it up held, it supported my statements:

i. The linked page, clearly reveals several formulas, and makes a qualifying statement,which I will now quote: “This table provides values for some normalized waveforms. All peak magnitudes have been normalized to 1.”

ii. Peak Voltage is Peak Voltage, whatever’s signals touch peak, are in fact at the max Voltage,meaning that they all have the same crest factor (1), which computes to 0dB, nullifying the central theme of your arguments.

c. You went on further, in the same reply to actually provide some math. Thank you. Math doesn’t lie. It clearly states what one believes, correct or otherwise.

i. The formula that you posted was for the determination of a crest factor, for a normalized sinewaves, or full-wave rectified – sine; pre clipping.

d. In the electrical, reproduction of music there are all manners of waveforms present, some as litigate representations of a musical instrument(s), and some as distortive additives. Many shapes, many frequencies,many sizes, during non-clipped conditions, not just sine waves.

e. When a waveform(s) is experiencing clipping,the fundamentals and harmonic frequencies (signals) receive the same Voltage and in essence, become normalized. On a scope, we see the evidence of this fact, as we view the crest of the waveform, which should be round, and dynamic, become flat, and steady. Within the affected degrees of a given signal(s), the formula for determining the crest factor is not the same, because RMS determination can no longer be applied, due to the fact that the current has no appreciable deviations / alternation in its delivery. Please note I have repeatedly expressed these truths, and that in my last posting to you, I further summarized that both DC, and Square waves, have 0dB of current/voltage headroom; which has now, just been verified by the data contained in the link that youreferenced. Bring about another contradiction, to your own claims.


3. Thirdly: you went on to quote me further: “During music, and especially during short incidents of clip, many wave forms are present. Your attempt to overlay a universal equation by meansof suggesting that merely one, normalized waveform type is present, is contemptuous toward truth.”

a. Your reply: The above completely ignores the simple and obvious fact that the CrestFactor of varying waveforms itself varies.” - “What a concept!”

b. Arny: Your reply supports the central theme of my point. You are agreeing with me, even though you start your statement intimating that you’re not; by saying that I am ignoring the very fact, that I have indeed posted above, to which you yourself, rebuked, just a little before (Point -2 above); making this a contradiction, within a contradiction.

c. You appear to be arguing with me and yourself. This is why I prefer math over English; numbers don’t lie, words do, and take far too many letters to express a simple truth, which often results insome clumsy typo’s, gramo’s and context drift etc. (no one is immune). If you mix in a little gamesmanship, the truth typically, becomes proportionally distorted.


4. Fourthly: You quote me as saying: “Lastly,when an amplifier is in a wide state of clip, the crest factor is 0dB, because at a minimum the waveform is closer to that of a square wave than any otherwaveform (leaving aside DC for now, to make clear this one point) and allsquare waves have a crest factor of 0dB.”

a. Your reply: Finally, in the midst of confusion and errors, a true statement!Huzzah!”

b. Arny: A clipped signal, receives its current delivery directly (with zero or near zero delay), just like a Square wave, just like, straight-up DC, if you will. They all have a constant voltage/current delivery, making their crest factor calculations different from that of AC deliveries; but making their crest factor the same 1, which equals 0dB; which is to say, that there is no crest factor, available during incidents of direct current deliveries.

c. By agreeing with me on this point, you contradict the stances that you took against me, in all other points, because all of the points that I have made, are locked with each other mathematically, if ones true they’re all true, if one is false, they’re all, false.


I can go on, but I amgoing to stop here, because I believe that I have stated / evidenced enough to support what I am about say.

I don’t for oneminute, believe that you, or several others for that matter, don’t know and have a good grasp of the math and theory relating to the things that have been introduced thus far. Do I believe that some of this stuff will at times come back to us alittle bit fuzzy – I sure do! Do I also believe that in our rush to postulate in our replies, in the name of gamesmanship that we make clumsy errors in our typing, grammar and worse, our reasoning at times – I sure do! Do I believe that in and amongst all of this that we can communicate more effective – I sure do!

If we employ, less gamesmanship (not zero), more math, more consideration towards those making a clear,and legitimate effort, towards learning or teaching a subject; by gently setting them back on track, opposed to any alternative; I believe that there will be an increase in a meeting of the minds, if you will, and that on the whole, AVS will become a better place to hang out in.

I recently said in another thread that the biggest challenge in learning isn’t necessarily the collecting, sorting, and analyzing of data, but rather, how to effectively document and communicate it to varying audiences. There is no silver bullet approach, but I do think many of us can do better, myself included.

I’m going to take a pause and mediate on how I personally, can better communicate the knowledge that Ihave collected over the years. When I return, I will return with less gamesmanship (not zero), more math and a kinder spirit.

When I return, I hope many of you will engage with me, in like manner.
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post #73 of 116 Old 08-09-2014, 03:56 PM
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Originally Posted by Garidy View Post
Food for Thought:

The terms DC and AC are used to visually describe in the English language, the general nature of a 'currents' state in delivery, as opposed to using the numeric language of mathematics. These are in fact, general terms, not absolutes. DC has ripples, which can be visually perceived on many scopes,especially digital scopes, as having an AC component, at a particular level of magnification. Inversely, the same statement can be made about AC; however,viewing them at a correct level of magnification (one that’s in keeping withthe standard notation) reveals that they each have very different properties,relating to how the current is delivered. One is direct (0Hz) and another is on a carrier frequency.

The math that explains the applied wattage within a DC circuit is different from that of an AC circuit, due to the presences of the carrier frequency(s). DC calculations are not complex; however, AC calculations are extremely complex.

Moving away from the math, just for now, I’d like to return to the visual representation of 'current' as it appears on a scope. Using Amir’s measurement, we discover that both channels are clipped, one more than the other and at different Voltages (let’s not read into the quality of this product at thistime). Note: that the flat top of the Yellow trace resembles the delivery of 'current' in a way that is more direct (closer to DC) than alternating (AC).

During periods of more DC then AC deliveries, the wattage is no longer calculated using an RMS determination (for sine waves); it is determined using peakVoltage. Instead of developing a mean of 70.7% of peak, 100% of the Voltage is applied, respectively.

Now, for some math; but just before I get into that, please also note that for the duration that clip is occurring, for a give portion of a waveform, the impedance, becomes mitigated to a range nearing or equaling the total DC resistance of the voice coil (6.5-Ohms in most 8-Ohm Nominal products).

AC Wattage

RMS Wattage of an AC signal @ 90 & 270 Degrees = (Peak-to-Peak x .707) x Impedance (nominal 8-Ohms)

Peak-to-Peak clipped yellow 81.5 Volts AC x .707 = 57.62 VAC RMS

(Divide Peak-to-Peak score by 2) x Impedance = non-clipped RMSpower = 28.81 VAC x 8-Ohms (Nom.)

RMS Wattage of a non-clipped AC signal equals – 230.48 Watts AC

Note that my Voltage calculations are in good agreement with Amir’s scope, which calculated 29.293 AC RMS – the deviation deriving from the truncating of decimal places and not the formula.

DC Wattage

The Total Wattage Applied for DC is the Voltage x DC resistance voice coil resistance (6.5-Ohms).

81.5 / 2 = 40.75 VDC x 6.5-Ohms DC = 264.875 Watts (delivered more as direct current than alternating), making them mathematically and inreality DC Watts.

Some summary facts (more to be addedalong the way):

1. The presence of DC causes a driver to ‘hang’ or alternate less, for the full duration of its presence (across all degrees of delivery), within a waveform.

2. When hanging occurs, heat increases, driver venting is lessened and therefore cooling decreases, and all manners of distortion increase, while further reducing MTBF scores (Mean Time before Failure).Increased heat weakens adhesives and burns voice coils, but kills sonic goodness's well before driver failure.

3. In Higher Fidelity applications, 0% of clip is acceptable – period.

4. One may crudely determine the % of DC wattage vs. % of AC wattage present within a measured signal, by means of adding up the number of degrees within a waveform that are derived from the delivery of DC, and subtracting them form 360-degrees. The balance will total the wattage derived from AC delivery.

5. Degrees and time are interchangeable – view thegraph.

6. In the presence of a clipped signal, most raw drivers cannot survive long term exposure of more than 25% of their rated RMS AC wattage.

a. I.e. a 200 Watt RMS AC driver is likely to fail with exposure to wattages derived in part or in whole, from 50-watts of DC and onwards, which is to say, that as a rule of thumb, drivers can only withstand approximately 25% DC of a rated AC RMS wattage.

7. If a signal is heavily clipped, say for 270-degree of a waveform, but the clipped voltage is under 25% of the rated RMS power handling of a raw driver, the driver will not fail due to thermal overrun. It will sound poor, and if ran in free air, may suffer mechanical failures.


So these are some truths to consider, before you develop yourfinal stance.


Once we debate through what I have posted above; I will post mathematical evidence, that DC, in the traditional/common sense use of the acronym, is in fact produced at all amplifier outputs and can become problematic to frequency response and become exacerbated during durations of clipping.

A few steps at a time as they say, opposed to one-step at a time, which they also say.
Quote:
Originally Posted by Garidy View Post
...

I'm not here to sell the idea that a clipped signal has become DC, or a square wave (at least not intentionally, thanks again for pointing out my clumsy error).

Thanks again
Then what were you trying to sell in the above post of your?

Also, I am still waiting for a follow up to your post 43, thanks.
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Then what were you trying to sell in the above post of your?

Also, I am still waiting for a follow up to your post 43, thanks.
LOL - Facts, what else.

I haven't forgot about you. You see something from me tonight.

Cheers..

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Originally Posted by Garidy View Post
Without math to support your claims, I'm sorry, but I cannot be swayed. Much of what you have posted seem to have been composed in hast. It's clear that you haven't carefully read, and re-read every word that I have posted. Harmonics and Fundamentals are just signals, signals that all get pegged to the limit of the Voltage rails output, during their propagation within a clipped portion of the wave... I've said this over and over. Distortion is just another name / adjective to describe the qualities of a part of a waveform, a whole waveform, or even an envelop, etc.. It's just energy, it all gets the same treatment when it's in the throws of clipping, if you will.

We are still at step one:

A VC burns only from exceeding the thermal wattage tolerances. Wattage can be produced by either Pure AC energy delivery, Pure DC energy delivery or a mix of the two. AC and DC are not energies- just the delivery types for electrical energy. Think back to Edison end Tesla, they were both selling Power - Coulombs. They both charged by the Kilo-watt, or some such scale; however, one used DC to deliver their energy and the other used AC. So, to a VC, current is current - it's all just coulombs, DC or AC - just coulombs. When coulomb are directly applied to a circuit the voltage and current are locked in phase, in a steady state of delivery. Because the power delivery is absolutely pure (P) not reactive (Q), and non-varying, it can produce more work than AC of the same Voltage and load, if you will. Now, a VC can only handle so many coulombs, for a given period of time, before it will fail - thermal tolerance overrun. DC is able to transfer more current than an alternating current, of the same Voltage, for a given period. The divide between them is based on the frequency and phase angle of the AC carrier. It can be mathematically calculated. In any event, current applied directly, without any gaps, intervals, pauses etc., will heat up a VC faster than any delivery method that spreads the delivery out, over time, and who's power (P) isn't absolute, but rather determined by subtracting the reactive power Q, produced by the presence of inductance and capacitance (which produces phase angle errors). An equivalent AC Voltage will always contain less potential, to perform work, when all other factors being equal, such as load.
Here's the math, as I understand it. Again.

First question is what’s clipping? There’s actually not a settled answer. Frequent poster around here ArnyK would call it clipping at the point where the total harmonic distortion (THD) versus power curve tilts up - - the knee of the THD vs power curve. Different for every amp, not uncommonly somewhere around .01 percent distortion. On the other hand, Stereophile and its sister publication sound and vision use one percent, typically, as clipping. So for example, at 8 ohms, this Anthem receiver http://www.soundandvision.com/conten...ver-test-bench shows the knee of the curve right about 95 watts, at 0.007 percent distortion, and hits one percent distortion at 138.2 watts, according to the S&V tests. It hits 2% at about 145 watts and IMO unusually stays right around 2% out to 195 watts. More common to see the distortion curve either keep the same slope or become steeper as power increases, and others would have to opine as to what design gives the kind of result shown there (which is, BTW, beside the point).

On the other hand, AIUI, it’s not unusual for musical instrument amplifiers to be specified at a whopping-ish 10% distortion. They aren’t subject to FTC power rating rules, so they don’t often even state the THD at which power is rated in their specs.

Anyway, here’s the math of it. Let’s imagine 4 different amps. The first hits 100 watts at .001 percent distortion, the second hits 100 watts at 1 percent distortion, the third hits 100 watts at 10 percent distortion and the fourth exhibits 20 percent distortion at 100 watts.

1. at .01 percent distortion, the distortion products are, by definition, 80 dB below the fundamental, undistorted signal. Here’s a nice calculator for this http://www.sengpielaudio.com/calculator-thd.htm.

2. at 1.0% distortion, the distortion is 40 dB below the undistorted signal (using the same calculator)

3. at 10% distortion, the distortion is 20 dB below the undistorted signal (again, same calculator)

4. at 20% distortion, the distortion products lie a mere 13.979 dB below the undistorted signal.

From a power perspective, every 10 dB is a power factor of ten. This page has a handy table, although you’d have to interpolate a lot, if you scroll down a bit . . . called a dB to ratio conversion table http://www.rapidtables.com/electric/decibel.htm and it’s perfectly obvious that every minus ten dB yields an additional power factor of 1/10. So amp 1, at 100 watts and .001 % distortion, includes roughly .000001 watts of power in the distortion part of the wave form (that’s 0.00000001 times 100 watts). Amp 2, at 1% distortion, includes distortion products in the range of .01 watts (0.0001 times 100 watts). Amp 3, at 10 percent distortion, would have roughly one watt of power in the distortion portion of the waveform (.01 times 100). For amp 4 I’ll round up to 13 dB just because it’s easier math (3 dB is a fifty percent power factor-see the table), so you end up with 100 watts times .05 or 5 watts in the distortion part of the waveform.

See? If the hundred watts would cook a particular speaker, even at 20% distortion, the chances that it’s the extra five watts that really do the deed are just not that strong, IMO. And, from my general reading, in music reproduction , that one percent THD level is about where the distortion becomes noticeable with at least some normal content to at least some people. Distortion twenty times higher, like amp 4, will surely be generating significant ugliness, sonically, even though the distortion is a relatively small part of the power.

Of course, in any single real word amp, THD increases with power. For example, here’s a Bryston. http://www.soundandvision.com/conten...-labs-measures. At 8 ohms we see the knee of the THD versus power curve at a little over 95 watts and .001% THD. 0.1 percent distortion arrives at 133.2 watts, where the distortion lies 60 dB below the signal, or about .0001332 (.000001 times 133.2) watts will constitute distortion, and 1% distortion arrives at 151.3 watts, where .01513 watts of the power will be distortion, roughly (.0001 times 151.3). We can see 10 percent distortion at about 190 watts, where the distortion will constitute about 9.5 of those watts.

If enough of those "extra" 9.5 watts are above the crossover in a speaker that's already close to trouble, you could kill a speaker with the total power. It's still total power and the tweeter just doesn't give a flying freak whether the power is from added harmonics of clipping, cleanly delivered power for a clean sine wave, added harmonics from violin bowing techniques, or distortion because Terry Kath plugged the power output of one guitar amp into the input of a second guitar amp to achieve massive distortion . . . . In the end, its' the power.
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Originally Posted by JHAz View Post
It's still total power and the tweeter just doesn't give a flying freak whether the power is from added harmonics of clipping, cleanly delivered power for a clean sine wave, added harmonics from violin bowing techniques, or distortion because Terry Kath plugged the power output of one guitar amp into the input of a second guitar amp to achieve massive distortion . . . . In the end, its' the power.
+1. Actually he used a Fender Showman into a Bogen PA amp. At its best those 60s vintage Bogens ran around 10% THD, and with that setup I wouldn't be surprised at all if Terry was getting 40 to 50%. But of course since he used the Fender to clip the living daylights out of the input stage of the Bogen but the Bogen couldn't produce more than 100w no matter what the THD it didn't bother his JBLs in the least.

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Originally Posted by Garidy View Post
A VC burns only from exceeding the thermal wattage tolerances.
Not exactly true. VCs, especially tweeter VCs have a pretty common failure mode where the lead wires break due to excess flexiing due to too much power at to low of frequencies. This happens to drivers operating in lower ranges, but it is far less common.
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Here's the math, as I understand it. Again. - Thank you!

First question is what’s clipping? Clipping is in part, what the name implies. It's an occurrence in which, one or more signals, suffers a waveform distortion that appears on a scope as if the crest of it's signal(s) has been clipped off. This occurs from the missusage or application of preamps, amplifiers and alike devices. It is caused by user error. There are many factors that introduce distortion into the signal path, clipping is just one of them; however, clipping is a distortion that can be 100% avoided. Clipping isn't determined by the point at which the increase in THD or IM start, it's determined by noting the compression of the signal, due to insufficient Voltage from the rails. A significantly clipped signal has an obvious, audible distortion to the ear and visual distortion on the scope. As more of a waveform enters into clip, the more audible and visual the distortions. However, by time one usually hears it, the deletion occurring in the Voltage rails has already commenced prior, which in turn has already altered the nature of the current delivery to the VC, to be at times, more of a steady state delivery then that of an alternating delivery. As the depletion increase, and more of the waveform incurs clipping, even more of the current delivery to the VC, becomes more steady state than truly alternating. Under heavy duress, a signal can be clipped for 80-90% of the waveform, making the current delivery virtually steady state for most of the waveform, and decidedly far from AC. This is how heavy incidents of clipping can and have burned VC's, when the amplifier is output more of a DC-Watt than an AC Watt. The speakers DC wattage rating is much lower than it's AC wattage rating, ,,,, because,,, the VC is receiving more coulombs, in a given period then it normally would with pure AC; because the signal current delivery is now closer to/ at 0Hz for more/most of its waveform, and the AC impedance is no longer playing the biggest part, but the DC resistance of the VC does, which is lower than nominal AC loads; because It isn't cooling as much, either... which all leads up to a quicker heating of a VC's coil, and in cases of failure, a surpassing of the thermal tolerance of the VC.

At little math - Short generalized example - Context Heavy Clip at least 50% of the waveform: No EQ boosting or cutting. - Flat eq...

200 watt amp: @ 8-Ohms = 40-Volts @ 5amps

50% AC = 40-Volt / 5-Amps @ 8-Ohms = 200-Watts RMS - No 0% Clipping - a 200-Watt RMS drive can handle this.

50% DC = 56.4-Volts / 8.67-Amps @ 6.5-Ohms = 489.37 Watts - Continuous During Clipping - The same drive would eventually lose it's VC, within a short period. (note: the increase on Voltage is = to Peak Voltage - increase in amps is based in reduction in Ohms, which is = to VC's DC rating)

The more degrees of a waveform that are experiencing clipping, the faster a VC will heat up, and if enough Wattage is available to surpass the thermal tolerance limits, the faster the coil will burn.

When such occurs, the VC doesn't cool as effectively, and actually lowers the AC RMS limit, to below 200. Also, very few driver can't handle much more than 25% of their AC RMS Wattage rating, in pure DC. In this case that would be about 50-ish watts; however, AC is present, and the drive is moving and venting and their is in fact a break between the AC cycle and the decidedly more DC cycles (but not pure DC cycles of current deliveries), so the tolerance is greater than if it was a 100%-steady state of direct current deliver to the VC (there are other factors relating to Q & P power scores that make clipped power less reactive and therefore of more P than Q power - if you don't understand the difference between Q & P power states, read through some of my other post, as I provided a sufficient explanation within them, or Google it). Once approximately 50% onward, of a waveform is against the rails, it isn't probable that a driver could indefinitely tolerate more than 40-60% of it's AC RMS.

In this case we'll use 60% x 200 = 120-Watts, and in our example we're inputting approximate 489.37-Watts from more direct, than alternating current for 50% of each cycle - hence how and why the 200-Watt RM/400 Peak Driver's VC, will burn from a 200-Watt RMS , 400-Watts Peak AC.

It is current that kill's - but it's how it's delivered that's most important - It needs to remain 100% pure AC, or all kinds of poor things will start to develop, inclusive, but not limited to VC damage or death - stay out of clipping and none of this matters! And if you like your music loud make sure your speaker are at least rated at twice the RMS wattage of the amplifier. If the amp's rated at 200, then make sure your speaker s are rated for 400, because you just learned how in fast, prolonged and widespread clipping can kill a 200-Watt AC RMS VC power from a 200-Watt RMS amp.

So as I close I want to make this abundantly clear: Heavy Clipper's - we all know someone who is a friend or friend of a friend, that cranks everything to full, and boost the heck out various frequencies, usually bass and still wants more. Nothing wrong with that except - their clipping the you know what out of every stage! 80-99% clipped waveforms are the norm for Clipper's! At even just 90% against the rails, the Wattage handling of their drivers would be reduce to about 40%.

When any amplifier is all out clipped, it's output of current to the speaker is much more direct than alternating, closer to 0Hz most of the time, in its delivery. This in turn means that the resistance that the amplifier sees most often, its that of DC rating of the VC. In a sense, in these states, an amplifier is just a really high wattage, poorly regular DC power supply, for 80-99% of a cycle. Your speaker RMS rating is based on 100% pure AC signal - Not 80-99% DC, of even 10% DC, but it can survive indefinitely on 10%.

So if this person has a 200-mono amp like above, running on a 400 RMS Subwoofer, the subwoofer would fail shortly after 160 Watt's of exposure, on a hot summer day, in a subwoofer box in a sealed trunk of a car, it won't take long to burn!

This is a classic case of an amplifier being under funded in PURE AC-WATTAGE! The Clipper should of had a BIGGER AMPLIFIER, at least a 400-Watt RMS amp.

FLAT-LINES are BAD-LINES because they LEAD TO DEATH!

There’s actually not a settled answer. There is, it is as I just generally explained. It has nothing to due with THD or IM, as they're the products, not the cause. Something has to cause a distortion, clipping is just one of many distortion causing factors. Occurrences of clipping are always the end-users fault. Even if a produce ends up being a big piece of you know what -it's still the end-users fault for buying it.

Frequent poster around here ArnyK would call it clipping at the point where the total harmonic distortion (THD) versus power curve tilts up - - the knee of the THD vs power curve. Different for every amp, not uncommonly somewhere around .01 percent distortion. On the other hand, Stereophile and its sister publication sound and vision use one percent, typically, as clipping. So for example, at 8 ohms, this Anthem receiver http://www.soundandvision.com/content/anthem-mrx-710-av-receiver-test-bench shows the knee of the curve right about 95 watts, at 0.007 percent distortion, and hits one percent distortion at 138.2 watts, according to the S&V tests. It hits 2% at about 145 watts and IMO unusually stays right around 2% out to 195 watts. More common to see the distortion curve either keep the same slope or become steeper as power increases, and others would have to opine as to what design gives the kind of result shown there (which is, BTW, beside the point). - these statements about % are directly proportional to how many degrees of a waveform are experiencing Voltage deficiencies (clipping), I have been repeatedly been speaking to this; teaching the root. Clipping is a layman's term. Rail Voltage Depletion is in fact what it actually is called, clipping is what occurs.

On the other hand, AIUI, it’s not unusual for musical instrument amplifiers to be specified at a whopping-ish 10% distortion. They aren’t subject to FTC power rating rules, so they don’t often even state the THD at which power is rated in their specs. In these cases, the instruments amplifiers are musical instruments themselves, not to be confused reference reproduction amplifiers. The distortions are intentional and part of the sound. Lastly, and most importantly, an amplifier doesn't have to be driven into clipping to product a high THD scores. I can get any level I want through other means, and not clip my amp, by even a pico-volt.

Anyway, here’s the math of it. Let’s imagine 4 different amps. The first hits 100 watts at .001 percent distortion, the second hits 100 watts at 1 percent distortion, the third hits 100 watts at 10 percent distortion and the fourth exhibits 20 percent distortion at 100 watts.

1. at .01 percent distortion, the distortion products are, by definition, 80 dB below the fundamental, undistorted signal. Here’s a nice calculator for this http://www.sengpielaudio.com/calculator-thd.htm.

2. at 1.0% distortion, the distortion is 40 dB below the undistorted signal (using the same calculator)

3. at 10% distortion, the distortion is 20 dB below the undistorted signal (again, same calculator)

4. at 20% distortion, the distortion products lie a mere 13.979 dB below the undistorted signal.

From a power perspective, every 10 dB is a power factor of ten. This page has a handy table, although you’d have to interpolate a lot, if you scroll down a bit . . . called a dB to ratio conversion table http://www.rapidtables.com/electric/decibel.htm and it’s perfectly obvious that every minus ten dB yields an additional power factor of 1/10. So amp 1, at 100 watts and .001 % distortion, includes roughly .000001 watts of power in the distortion part of the wave form (that’s 0.00000001 times 100 watts). Amp 2, at 1% distortion, includes distortion products in the range of .01 watts (0.0001 times 100 watts). Amp 3, at 10 percent distortion, would have roughly one watt of power in the distortion portion of the waveform (.01 times 100). For amp 4 I’ll round up to 13 dB just because it’s easier math (3 dB is a fifty percent power factor-see the table), so you end up with 100 watts times .05 or 5 watts in the distortion part of the waveform. Very interesting, but not relevant - THD doesn't cause Clipping - Voltage Depletion does, and it's the truncating of transients (waveform distortions) that are in fact the root of THD. THD and IMD for that matter are present before and amplifier inters into clipping. Clipping isn't the sole source of THD or IMD production.

See? If the hundred watts would cook a particular speaker, even at 20% distortion, the chances that it’s the extra five watts that really do the deed are just not that strong, IMO. And, from my general reading, in music reproduction , that one percent THD level is about where the distortion becomes noticeable with at least some normal content to at least some people. Distortion twenty times higher, like amp 4, will surely be generating significant ugliness, sonically, even though the distortion is a relatively small part of the power.

Of course, in any single real word amp, THD increases with power. For example, here’s a Bryston. http://www.soundandvision.com/content/bryston-sp3-surround-processor-and-9b-sstsup2-amplifier-ht-labs-measures. At 8 ohms we see the knee of the THD versus power curve at a little over 95 watts and .001% THD. 0.1 percent distortion arrives at 133.2 watts, where the distortion lies 60 dB below the signal, or about .0001332 (.000001 times 133.2) watts will constitute distortion, and 1% distortion arrives at 151.3 watts, where .01513 watts of the power will be distortion, roughly (.0001 times 151.3). We can see 10 percent distortion at about 190 watts, where the distortion will constitute about 9.5 of those watts. Our context is Clipping (of raw drivers) - not THD - THD cannot electrically kill a speaker, unless the wattage within its signals exceed the thermal limits of the VC (or it's root cause is due to an amplifiers malfunction - but that's not within the scope of our current context - all things being equal and good - just good old fashion Voltage depletion is a foot. - We will progress to include more variables, after we get this nailed down), nor can a square wave, nor can a sine wave, nor can DC. A VC has a DC and AC Wattage Rating (AC being the highest and DC being the lowest - you mix them you ended up somewhere in the middle.). It is based on temperature - temperature is based on the presence of coulombs vs. cooling. The temperature and duration fail point is the same for both AC & DC, but where they differ, is in the rates at which they deliver coulombs and the rate at which the systems they're powering, can dissipate heat. In the case of a speaker, the more it alternates the more it exchanges the air around the VC and motor system, the less it moves, the less it cools. In the case of a speaker, the current is delivery is assumed to be made overtime, and not as a steady state delivery of current. I have thoroughly explained this prior to you making this last posting.

If enough of those "extra" 9.5 watts are above the crossover in a speaker that's already close to trouble, you could kill a speaker with the total power. It's still total power and the tweeter just doesn't give a flying freak whether the power is from added harmonics of clipping, cleanly delivered power for a clean sine wave, added harmonics from violin bowing techniques, or distortion because Terry Kath plugged the power output of one guitar amp into the input of a second guitar amp to achieve massive distortion . . . . In the end, its' the power.
In the End it's about AC Vs. DC Power Delivery! Please Read above.

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DC is irrelevant as there is no DC in a clipped signal. I think I sense deja-vu.

Voltage rail depletion? Seriously? In 30 years in linear electronics, this is the first time I've ever come across the term. I don't recall it in Self and Cordell's books either, nor any of my other reference works. Google brings up nothing useful. I think you're playing with yourself.
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Originally Posted by A9X-308 View Post
DC is irrelevant as there is no DC in a clipped signal. I think I sense deja-vu.

Voltage rail depletion? Seriously? In 30 years in linear electronics, this is the first time I've ever come across the term. I don't recall it in Self and Cordell's books either, nor any of my other reference works. Google brings up nothing useful. I think you're playing with yourself.
You are misreading my commentaries or simply making cheese.

DC is not energy friend, it's merely a description of the state in which current is being delivered. In extreme states of clipping, as to cause seemingly premature voice coil failure the voltage is almost 100% constant through the entire waveform. The RMS rating of the driver is listed for pure AC sine wave. Meaning that the maximum voltage is expected to occur at 90 and 270-degrees, not all, or at almost all 360. That makes the current delivery, more steady state in nature then alternating. When a Voltage is applied with minimal to no fluctuations, the resistance of the VC is much, much closer to DC rating, then any AC nominal Impedance. Also the cooling of the VC and motor structure diminishes, due to the decline in AC deliveries.

I think I sense ignorance!

Please feel free to explain another means in which a 200 Watt amplifier that has no issues of oscillation, DC-offset, or other malfunctions, can through means of clipping alone, cook a 400 Watt RMS Subwoofer - it happen almost everyday of the week. Feel free to use your teacher for help - Google!

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post #81 of 116 Old 08-10-2014, 10:05 PM
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DC is not energy friend, it's merely a description of the state in which current is being delivered.
It is not being delivered as DC, it's still AC. Again, read Fourier.

The only ignorance I'm seeing is yours.
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post #82 of 116 Old 08-10-2014, 10:08 PM
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The RMS rating of the driver is listed for pure AC sine wave.
Not necessarily. Try AES2-1984, band limited pink noise.
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post #83 of 116 Old 08-10-2014, 10:23 PM
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I personally have never seen a 400 watt "rated" and rated being a key word, because it's just a number attached to the specs by the manufacturer, being "cooked" by a 200 watt "rated" again, a key word, amplifier, clipping or not.

If a true 400 watt maximum woofer was driven by a true 200 watt amp, it would take an unnatural occurrence to "cook" that woofer, like amplifier failure of some kind.

I've damaged just two subwoofers my whole life, I'm 46 and have messed with audio at least the last 30 years+ of that time, both car audio subs, once a 90's vintage Kicker C10 by a Hifonics Pluto amp that seemed to have a DC problem as it also ruined full range coaxial speakers on several occasions, and once I buckled the cone of an aluminum coned subwoofer driver that apparently couldn't take the stress of a small sealed enclosure even though it was touted as such.

A little while back, the woofer of a JBL L80t locked up on me, but was surely an age thing, and a tweeter of a JBL HLS620 took a dump, but those cheap mylar tweeters are notoriously weak and die without known cause. That is it as far as speaker damage...and I've had a lot of different stuff over the years, both car and home audio.
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post #84 of 116 Old 08-10-2014, 10:38 PM - Thread Starter
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I personally have never seen a 400 watt "rated" and rated being a key word, because it's just a number attached to the specs by the manufacturer, being "cooked" by a 200 watt "rated" again, a key word, amplifier, clipping or not.

If a true 400 watt maximum woofer was driven by a true 200 watt amp, it would take an unnatural occurrence to "cook" that woofer, like amplifier failure of some kind.

I've damaged just two subwoofers my whole life, I'm 46 and have messed with audio at least the last 30 years+ of that time, both car audio subs, once a 90's vintage Kicker C10 by a Hifonics Pluto amp that seemed to have a DC problem as it also ruined full range coaxial speakers on several occasions, and once I buckled the cone of an aluminum coned subwoofer driver that apparently couldn't take the stress of a small sealed enclosure even though it was touted as such.

A little while back, the woofer of a JBL L80t locked up on me, but was surely an age thing, - how can age lock up your driver, was the VC exposed to water and rusted...

and a tweeter of a JBL HLS620 took a dump, but those cheap mylar tweeters are notoriously weak and die without known cause. - the cause is determinable.

That is it as far as speaker damage...and I've had a lot of different stuff over the years, both car and home audio.
I have tight relationships with every large Car Audio manufacturer that does business in Canada, they all get burnt coils warranty requests, weekly; for the reasons that I've stated. Future Shop Special: 2x 12" 400 RMS - amp in the box 250 RMS at 2 -ohms all for 299.00 = fry time - at least a dozen different brand with the same priced package and story...

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post #85 of 116 Old 08-10-2014, 10:40 PM - Thread Starter
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Not necessarily. Try AES2-1984, band limited pink noise.
If you're going keep serving the cheese, I'll soon have enough to invite some friends over.

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post #86 of 116 Old 08-10-2014, 10:49 PM
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Both the JBL L80t woofer, and HLS620 died seemingly out of no where. I have the amplifier power to reach the levels I need without even remotely clipping the amps. The L80t woofer may have gotten some foreign debris in the gap, although I don't how, or something else. Anyway, they were 30 year old speakers and I had only owned them somewhat recently so who knows, but it wasn't clipping. The cheap mylar JBL HLS620 tweeters seem to have a reputation for dying as they see fit. Perhaps it's more of a crossover point problem...or the tweeters just suck.
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post #87 of 116 Old 08-10-2014, 10:53 PM
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You were just as boring and smug in your previous banned incarnations.
Unsubscribed.
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post #88 of 116 Old 08-10-2014, 11:10 PM - Thread Starter
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Both the JBL L80t woofer, and HLS620 died seemingly out of no where. I have the amplifier power to reach the levels I need without even remotely clipping the amps. The L80t woofer may have gotten some foreign debris in the gap, although I don't how, or something else. Anyway, they were 30 year old speakers and I had only owned them somewhat recently so who knows, but it wasn't clipping. The cheap mylar JBL HLS620 tweeters seem to have a reputation for dying as they see fit. Perhaps it's more of a crossover point problem...or the tweeters just suck.
It sure sounds like you got you're money out of the gear. A lot of older drivers, have/had more biodegradable suspension material, then we today, which has been known to lead to VC misalignment. Which would over time lead to rubbing and eventual failure with otherwise normal usage. Just a highly assumptive guess. Tweeter cross-over sound probable, but again, just a big guess.

Thing do just ware out. I made an assumption that I shouldn't have, when you said old: I was thinking in terms 10-maybe 15 - not 30 years... That's a lot of years more copper to diminish as well.

Hey, in your opinion do you think the sound of your speakers changed throughout those years?

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Last edited by Garidy; 08-10-2014 at 11:17 PM.
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post #89 of 116 Old 08-10-2014, 11:14 PM - Thread Starter
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You were just as boring and smug in your previous banned incarnations.
Unsubscribed.
Even as you retreat you can't get things straight!

I am not whom you perceive me to be, and secondly, you cannot unsubscribe, from something you hadn't subscribed to, in the first place.

Fair the well, the one whom delivers the cheese!

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post #90 of 116 Old 08-11-2014, 12:12 AM
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It sure sounds like you got you're money out of the gear. A lot of older drivers, have/had more biodegradable suspension material, then we today, which has been known to lead to VC misalignment. Which would over time lead to rubbing and eventual failure with otherwise normal usage. Just a highly assumptive guess. Tweeter cross-over sound probable, but again, just a big guess.

Thing do just ware out. I made an assumption that I shouldn't have, when you said old: I was thinking in terms 10-maybe 15 - not 30 years... That's a lot of years more copper to diminish as well.

Hey, in your opinion do you think the sound of your speakers changed throughout those years?
I didn't buy either new. The L80t's are later 80's vintage, and I bought them maybe 3-4 years ago.

The HLS-620 are mid 90's vintage and I also bought those used, but the tweeters are junk, $5 tweeters at best, I believe they are Audax mylar domes...in fact I know they are as I replaced one. I think the crossover point is 1.8khz on that speaker, and it's probably 1khz too low, maybe even more for for a crap tweeter such as it.

I have older speakers, nearing 40 years old, such as my DCM Time Windows that hum along as new. You just never can tell.

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