Question: How do we know that nobody noticed? I occasionally bought 45 rpm records when I was a teenager and they always sounded horribly distorted. I sure hope nobody thinks I didn't notice. I thought 33 rpm records were distorted too, although not as badly, I thought it was our turntable causing the problem.
And comparing learning to hear distortion to long jumping? Odd. Probably more like learning to speak a new language fluently.
Regarding the high distortion in speakers, agreed. However, distortion from amplifiers is often quite audible even using lousy speakers. They don't distort the original distortion enough to make it inaudible any more than they make music inaudible because of their distortion.
So, here we are, going back and forth like two lawyers, trying to convince the jury, not each other. I wouldn't have had to do all this work, if you had only done my job for me in the first place, and argued both sides of the issues. 😀
What is so special to you about Alesis monitors? They list a bunch on their website.
I see why people like Audioengine like.. They might be good quality! I just prefer the fancy Kanto. They're not as good/expensive.. I just prefer them 🙂
Where does the 20% THD come from that hundreds of thousands of unsophisticated music lovers find acceptable, come from?
I had accurate inside information about their products - and most of their competition - at one time. I knew they were good, and not because I saw a shiny advertisement in the Sweetwater catalog!
There was a period in the late 1990s when Alesis had a very talented group of engineers working for them, including two excellent speaker designers. One of them designed actual drivers, the other designed loudspeaker systems. Working with a Taiwanese speaker manufacturer who custom-manufactured the drivers, these two guys created a number of speaker designs that punched well about their price class.
I knew both men, and got to see a lot of the behind-the-scenes work that they did. This was real R&D - there would be a round-and-round development cycle: new driver design, new prototype woofers and tweeters made at the Taiwanese factory, accurate measurements made on the prototypes, rinse and repeat, until the drivers were as good as they could be while fitting in the price budget. When the drivers were perfected, the system design would begin. More design, build, measure iterations, until eventually the system design was as good as it could be. These two guys took their work very seriously, and put their hearts and souls into it.
As I said, this process resulted in some very good speaker designs, only a few of which eventually made it to market (poor decisions by upper management). The cream of the crop was the (passive) Alesis Monitor One Mk II, followed by the (active) M1 Active.
I worked for an audio company at the time, and had the opportunity to critically listen to, and see measurements of, all the popular semi-pro nearfield monitor speakers of the time. The Monitor Ones were quite good, better than anything else around the same price point. When the M1 Actives arrived, they were even better.
Right around that time, the Mackie HR-824s arrived, and created a storm of interest. They were, indeed, very good - very neutral, very flat, very accurate. Also, very expensive compared to other competing products in the category.
I got to hear the HR-824s in an A/B comparison with the Alesis M1 Actives. The Mackies had deeper bass extension and tighter-sounding deep bass, but through the midrange and treble, the Mackie and Alesis speakers sounded virtually identical. And the Alesis speakers cost $400 a pair, while the Mackies cost $2400 a pair.
I also got to see frequency response measurements on both speakers. Sure enough, both of them had extremely flat frequency response through most of the audio range. The Mackies titanium tweeter went higher, but the difference wasn't audible. The titanium tweeter also had a huge "oil-can spike" at around 40 kHz - also inaudible, and not measurable unless you had a calibrated instrument microphone capable of going that high in frequency.
Earlier in this thread, someone posted a link to a PDF comparison of a number of monitor speakers, including the $2400/pair Mackie HR 824s, and the $400/pair Alesis M1 Actives. The PDF included anechoic frequency response measurements of all the speakers tested.
You can look at the PDF, and decide for yourself. (There were some incredibly bad frequency responses among some of the other speakers there, I might add.)
The story has a sad ending. Alesis Corp. went bankrupt around the year 2000. All employees were laid off (one committed suicide as a result.) Material assets were auctioned off for pennies on the dollar. The brand name, and a few designs, were bought up by some other large audio company.
So most, if not all, of the Alesis products you see for sale today, have nothing at all in common with the products I've been discussing. Some of the new products seem to be bad jokes (3-inch near-field monitor speakers? Oh, puh-leeze. 🙄 )
When you buy a product design, but fire the engineering team that created it, and the manufacturing team that built it, it is very hard to maintain the quality of the product. But that's what the new owners of the Alesis trademark did, back in 2000.
So, without seeing trustworthy third-party measurements on current Alesis products, I have no more trust in their quality than any of the dozens of other competing products on the market.
Please not that I'm not claiming that Alesis speakers were the best in the world, or anything like that. Simply that they were good, and I knew from seeing actual technical measurements, and doing actual listening tests, that they really were good.
These days I never even see an anechoic frequency response measurement accompanying an ad for a "monitor loudspeaker". They are sold on the same basis as those big red headphones (they're red, and have a rappers name on them, so they must be good, right?) So, among todays crop of monitor speakers, I have no idea what is good, what is bad, and what is indifferent.
-Gnobuddy
Sure. I have a couple of those here. Almost usable for mixing, but not quite. Definitely prefer NS-10's for that. But, the Monitor One MK II's are keepers. Fine for casual use.
That level of THD was common from both records and cassettes. I never heard a huge outcry from the public about how bad records and cassettes sounded, did you?
Even more extreme, for many decades, going all the way back to Edison's 1800s experiments with entirely mechanical gramophones, many people claimed they could hear no difference between live and recorded at all. I find that absolutely staggering, considering how bad those early all-mechanical recording/reproduction chains sounded.
Let's not forget that 20% THD is also very possible today - I myself measured 18% THD from a subwoofer in the late 1990s. (It was mostly 3rd harmonic distortion.)
In college, I once built a little power amp circuit (with an underbiased complimentary symmetry BJT output stage) to demonstrate crossover distortion to members of the public at a school science exhibition. I tested my prototype circuit on other students; most of them couldn't hear the distortion. 😱
So I removed the bias entirely from the output devices. Most people still couldn't hear the distortion. 😱
I gave up on that idea, and simply inserted a pair of paralleled, back-to-back silicon diodes in series with the loudspeaker. Success, people could finally hear that! ( It sounded incredibly harsh and grating to me, and I'm sure it would to anyone who's developed an ear for critically listening to distortion. )
Along similar lines, the most popular live vocal microphone in the world is the Shure SM 58. Literally millions of people have used it, and still use it. They range from world-famous music acts to unknown bar bands and public speakers. The microphone has been popular for decades.
Thing is, it's an utterly horrible microphone. Harsh, screechy, muffled. You'd think anyone with ears would be repulsed. Nope, it retains it's reign as the worlds most popular live vocal microphone. Most people don't hear the tremendous distortion this microphone introduces.
(Though I've found that if you do an A/B comparison with a decent condenser mic, a lot of people will instantly hear the difference.)
Hypothetical question: if you play background music to a thousand people at typical background-music SPL levels, and gradually introduce more and more pure 2nd harmonic distortion, how much do you think you'd need to add before, say, a hundred people (10%) notice?
I'll bet a coconut Bounty Bar you'd have to introduce over 20% distortion before 10% of casual listeners notice! 🙂
And I'll bet two Bounty Bars that not even 1% of the public will be able to detect 1% of pure 2nd harmonic distortion mixed in to the music. 😀
-Gnobuddy
Come one, now. We can't have a serious discussion about Hi-Fi when NS-10s show up in the same thread! 😀
-Gnobuddy
Wait a minute. An SM58 is an SM57 capsule with a wind screen. SM57 are widely used in recording studios. They only sound muffled into an inappropriate preamp. They like to be loaded at 2k ohms or higher. They sound even more clear loaded at 8k ohms. But, I know what you mean, with a cheap preamp. They sound fine with a Grace 101.
Regarding THD, 20% 2nd or 3rd harmonic is a lot less objectionable than 20% 7th harmonic. Lower order harmonics are musically related with the fundamental. Higher order harmonics are not. That's why THD is a measure of limited applicability.
Regarding THD, 20% 2nd or 3rd harmonic is a lot less objectionable than 20% 7th harmonic. Lower order harmonics are musically related with the fundamental. Higher order harmonics are not. That's why THD is a measure of limited applicability.
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I found a writeup that said the opposite; screechy as hell with 8k, much closer to neutral with 1k or so load:
- Shure SM57 Impedance Modification : Recording Magazine -
I won't spend the money to buy one of these #$@@ mics, so I can't speak from personal experience.
Sure, I bet everyone on this thread knows that well.
That may well be true of 10% THD, where, as you say, 10% of second-harmonic may be inaudible, while 10% of 7th harmonic is quite nasty.
But it's no longer true when THD drops below 0.1% or so. At that point, every distortion component is too low to be audible. The amp is audibly perfect. Even if the entire 0.1% is, say, 7th harmonic.
-Gnobuddy
Some people are not so convinced that is necessarily true in all cases and for every last person.
Also:
Mastering engineers can hear dither noise at a very low level. And its not hard to hear undithered 16/44 made from 24/96. The 16th bit is down around -96 db?
And IMD can be more objectionable than THD.
My primary concern is that when a number is stated like 0.1% THD as being good enough, people may tend to get the idea that's all there is to it. They may think only THD matters when buying an amp, or they even might get some idea that 0.1% is a magic number for any kind of distortion.
And, just maybe, a few people might be able to hear lower levels of the most objectionable THD, in some situations.
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the conversation will continue to be tedious, circular
if some level of knowledge, sophistication in "distortion" interpretation isn't assumed
never gonna get anywhere if everyone gets to "zing" "the other side" with moronic strawman misconstructions which then need refutation/clarification for the nth time for large n
if some level of knowledge, sophistication in "distortion" interpretation isn't assumed
never gonna get anywhere if everyone gets to "zing" "the other side" with moronic strawman misconstructions which then need refutation/clarification for the nth time for large n
Question about deadband: if that is something that may approximate a step or an impulse, then in theory, all frequencies are present. So, all harmonic?
Also, agreed, isolated high order harmonics don't tend to occur naturally, although they can be manufactured.
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Returning to some of the ongoing discussion recently in this thread, even if we are careful to try and use circuits that produce primarily low order harmonics, when cascaded, say, MM riaa-preamp > preamp > power amp, etc., then more objectionable higher order harmonics can build up. It would seem to make sense to want to know about overall system performance, and most people around here seem not to have access to much in the way of sophisticated test equipment.
Anyway, to say that it should be fine to have a power amp that has 0.1% harmonic distortion, even if mostly low order is specified, that doesn't say everything about whether or not a system will exhibit audible, objectionable distortion coming out the speakers, or earbuds, whatever.
Also, power amplifier distortion isn't the only possible concern. Damping can matter sometimes in terms of overall system performance. There might be other considerations too. So, again, it concerns me when people focus too much on a single number. It looks a lot like another normal, everyday case of Kahneman's WYSIATI.
Also, agreed, isolated high order harmonics don't tend to occur naturally, although they can be manufactured.
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Returning to some of the ongoing discussion recently in this thread, even if we are careful to try and use circuits that produce primarily low order harmonics, when cascaded, say, MM riaa-preamp > preamp > power amp, etc., then more objectionable higher order harmonics can build up. It would seem to make sense to want to know about overall system performance, and most people around here seem not to have access to much in the way of sophisticated test equipment.
Anyway, to say that it should be fine to have a power amp that has 0.1% harmonic distortion, even if mostly low order is specified, that doesn't say everything about whether or not a system will exhibit audible, objectionable distortion coming out the speakers, or earbuds, whatever.
Also, power amplifier distortion isn't the only possible concern. Damping can matter sometimes in terms of overall system performance. There might be other considerations too. So, again, it concerns me when people focus too much on a single number. It looks a lot like another normal, everyday case of Kahneman's WYSIATI.
Yes, I'm quite aware of that. Also quite aware that I certainly won't be the one to change their minds. 😀
We're claiming to hear -96 dB noise in a room with acoustic noise at -50 dB or so? That seems, shall we say, highly improbable.
Do we have a competently conducted, large-scale, double-blind study that shows this to actually be true? Otherwise it's no more than just one more audio myth. Right up there with red wires sounding better than black ones. 🙂
The data I've seen, most of it from studies made decades ago, says that 0.1% is indeed a magic number. I know of no credible, large-scale, competently conducted, double-blind listening tests showing 0.1% THD - in any form - was audible while listening to music - any music - to a statistically significant percentage of people.
Occam's razor applies here, as in all similar quandaries.
For example: Maybe, just maybe, there is a man who can actually bend spoons with with just his psycho-telekinetic powers?
I can't actually prove that there is no such man on planet earth. But, until I see clear and unambiguous proof that there is, the logical conclusion to make is the opposite one: there are 7.5 billion humans on the planet, and not one proven case of telekinetic powers. The logical conclusion is that nobody has telekinetic powers, and nobody ever will.
And, having made the logical conclusion, I move on with my life, and no longer pay any attention to spoon-benders. 😀
-Gnobuddy
Regarding hearing undithered 16/44 made from 24/96:
I don't recall the authors, but JCX recently posted their names in the "what's wrong with opamps" thread. I believe he said something to the effect that it is well established and non-controversial.
Regarding magic numbers, is 0.1% IMD the limit for that too? Or, is knowing an amplifier is rated at 0.1% all that one needs to know when shopping for one? I ask, because the argument given so far seems to THE is the only thing that counts.
And if your power amp has 0.1% THD and your preamp has 0.1% THD, and your phono stage or DAC output amplifier has 0.1% THD, then are you still good because your system only has 0.1% THD overall?
<\rant>
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Finally, you know why we disagree on this stuff at some deep down level, right? It's not because of the arguments we construct.
Its' because everybody tends to believe their own ears, then look for evidence to confirm why they hear what they hear.
For people who don't hear much distortion, they look for evidence of what they know to be true from their own experience, and ignore or discount any evidence to the contrary.
Same thing happens for people who do hear distortion.
The hearing for one's self comes first, then comes the search for confirming evidence, then comes construction of the story or argument.
The plausibility of a story is a function of it's coherence, the property of the story that all the pieces and parts of the story fit together perfectly, analogous to pieces of a jigsaw puzzle, and that the story has no holes or loose ends.
In brains, the coherence of a story causes confidence that the story is true. It's a feature that sometimes aids survival in a harsh, fast moving world.
But it turns out that coherence is completely uncorrelated with scientific truth.
Thus, the fact that coherence is a proxy for truth, also has the potential to cause huge problems. And it does all the time, in this world. For example, coherence has always been a proxy for truth in law. That's one reason why sometimes innocent people are convicted, or the guilty are not punished.
Such a strong bias can get us into lots of trouble in much less critical situations, like arguments in an internet forum. People get riled up when their stories are picked apart. It's an attack on belief's which are held in high confidence, and the natural tendency is to want to defend those beliefs.
Since you and I have some disagreement about what is, in the big picture, some fairly insignificant audio beliefs, I think we ought to agree to disagree and leave it at that. Getting hot under the collar and arguing isn't going settle anything. So, I think I will stop here. If you want to have the last word, please feel free.
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There will always be a 'tail' of people who have much better hearing than the rest of us. This tail is much smaller than many people think.Markw4 said:
Saying that 0.1% distortion is probably good enough for most people is not focussing on a single number - well, except in the sentence which says that. There may be another sentence in the same paragraph about bandwidth, or hum level, or noise level or the other things which a good amp needs to get right. Look at the paragraph, not the sentence. Also, remember that the reason for picking 0.1% is that tests have shown (I think) that not many people can detect 0.5% so there is a lot of contingency built in.
Believing your own ears is the first mistake made by many audiophiles. Then the second mistake is to fail to distinguish between what is actually heard and what is merely thought to have been heard. Remember, there are various tests which show that people can be persuaded to 'hear' changes which in reality have not actually happened. Finally, some people make the mistake of suspending whatever knowledge of science they have when looking for audio explanations - as though audio is uniquely disconnected from the rest of the universe with its GPS, inertial navigation, gravity wave detection etc. which seem to work just fine with ordinary physics.
None of which can be detected with our senses, so we MUST rely on machinery to sense them. So audio IS "disconnected" from them, at least.
And the third mistake of (some) audiophiles (who fall for the "snake oil" theories), is that when it is shown they can't hear certain differences they sigh in relief that it ISN'T any deficiency of their discrimination and thereafter refuse to believe that anything makes a difference. And become religious in their attacks on any who disagree. That's audiophiles I'm referring to, not necessarily mathematicians or scientists. But not excluding all of them, either. 🙂
I would suggest it is vivid imagination rather than ears that make an audiophile, plus a pot of money does no harm.
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