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Car Forum / Driving, Maintenance, Tuning / Car Audio / December 2004Car Amp Comparison
Hi, I recently bought a MTX 502 Thunder Amp and it's built like a tank and is quite hefty. It works great with my 12" sub. My (4) 6 x 9 speakers are powered by a Kenwood Excelon 4-channel X-614 amp. The MTX is only a two channel amp but weighs quite a bit more then the 4 channel Kenwood. This leads me to believe that the MTX probably has larger capacitors and Torodials. I was thinking of selling the Kenwood and replacing it with a MTX 4-channel amp. I'm wondering if anyone has done a comparison of car amps and if there is a big difference in sound quality from one manufacturer's amps to another ? Please refrain from posting if you're in the camp that they all sound the same............I know with home amps that this is not true and my ears are the proof. I've tested many amps on my system and have run them at low levels so they amp was not clipping and I could hear a difference when I flipped back and forth. Some amps produced better bass, some better mids, some had glaring highs, etc. Thanks Why did you bother asking? You already said you believe there are differences - in home amps, why would car amps be any different - and pre-emptively suggested that people that don't agree with you should shut up. This is a newsgroup intended for discussion of various car audio equipment and different viewpoints about the hobby. If you need to post just so you can hear other people agree with your own theories, you might want to try rec.audio.[insert your own name]... JD >Hi, > [quoted text clipped - 14 lines] > > I guess I didn't make myself clear. I want to discuss the SQ differences of car amplifiers that newsgroup owners have experienced. I.E. Kenwood vs. MTX, etc. I'm trying to decide if I should sell my Excelon and maybe by a SoundStream, ADS, JL or MTX. > Why did you bother asking? You already said you believe there are > differences - in home amps, why would car amps be any different - and [quoted text clipped - 23 lines] >>produced better bass, some better mids, some had glaring highs, etc. >>Thanks > I guess I didn't make myself clear. I want to discuss the SQ differences of > car amplifiers that newsgroup owners have experienced. I.E. Kenwood vs. > MTX, etc. I'm trying to decide if I should sell my Excelon and maybe by a > SoundStream, ADS, JL or MTX. Does this mean I can respond now? Cool. I've owened MTX, a/d/s, and Kenwood amps. I've installed even more. The older Kenwood PS series amps were brutes. Probably heavier than their MTX counterparts, since you're into the weight thing. The a/d/s/ amps are deceptively heavy too. All three manufacturers made good amps at affordable prices, IMO. I haven't had much experience with the newer amps from these manufacturers though, so I'm probably not of assistance. I go a/d/s/ all the way though simply because of the extensive crossover settings available on their multichannel amplifiers. Fair enough... but what makes the opinion of someone who thinks there is a SQ difference more valid than someone that has done the same comparison and didn't? You mentioned the capacitors and toroid contributing to weight below... chances are much better that the heat sink extrusion on the MTX plus the various trim parts and other metal items are far more responsible for a weight difference. Caps don't weigh much, and the difference in weight from one transformer to another wouldn't account for much in the way of perceptible weight. Plus, weight is a very poor indicator of amp performance in general. In that the kind of SQ differences you are talking about are far more subjective than objective - in other words, if you tried to measure for them using lab equipment in controlled circumstances you'd be hard-pressed to quantify any difference - shouldn't you do the same thing you'd do with auditioning speakers and do your own listening tests? Another person's opinion on how a particular amp sounded to them is just as irrelevant in terms of how it will sound to you as their opinion on a pair of speakers would be, no? JD >I guess I didn't make myself clear. I want to discuss the SQ differences of >car amplifiers that newsgroup owners have experienced. I.E. Kenwood vs. [quoted text clipped - 36 lines] > > > I guess I didn't make myself clear. I want to discuss the SQ differences of > car amplifiers that newsgroup owners have experienced. I.E. Kenwood vs. > MTX, etc. I'm trying to decide if I should sell my Excelon and maybe by a > SoundStream, ADS, JL or MTX. ADS is a high quality company in my experience. I believe Soundstream is as well, although I don't have one of their amps. > Hi, > [quoted text clipped - 4 lines] > leads me to believe that the MTX probably has larger capacitors and > Torodials. No. More like larger heat sinks. > I was thinking of selling the Kenwood and replacing it with a > MTX 4-channel amp. I'm wondering if anyone has done a comparison of car > amps and if there is a big difference in sound quality from one > manufacturer's amps to another ? Please refrain from posting if you're in > the camp that they all sound the same............ In other words, "engineers please don't respond". Gotcha. I apologize if I insulted anyone I just didn't want my post to turn into a debate about how a amp is suppose to simplify a signal and if it has a flat response you would only hear a difference when the amps distort or goes into clipping. I was just surprised how lighter my new Excelon amp felt compared to the new MTX amp I just bought. I'm not into the weight thing but I've found that a heavier amps usually means that they are built better. This is not always the case. The design of the circuit, quality of parts used, etc. all play a roll in the overall SQ. And yes I was interested in subjective responses. There are many people who have owned multiple amps and have taken the time to do comparisons. I'd love to hear their opinions. I use to own class A car amps which I remember as having a richer sound but I've never compared them side-by-side to a class AB amp so......Anyway, I'd still love to hear your opinion. >> Hi, >> [quoted text clipped - 15 lines] > > In other words, "engineers please don't respond". Gotcha. > I apologize if I insulted anyone I just didn't want my post to turn into a > debate about how a amp is suppose to simplify a signal and if it has a flat [quoted text clipped - 9 lines] > I've never compared them side-by-side to a class AB amp so......Anyway, I'd > still love to hear your opinion. My opinion, based on bench testing amplifiers, designing amplifiers, building amplifiers, and in general trying to learn as much as I can about amplifiers, is best summarized by your first sentence. By the way, your question regarding sound quality comparisons between amplifiers may yield more responses in a more technical minded newsgroup, such as rec.audio.tech. > I apologize if I insulted anyone I just didn't want my post to turn into a > debate about how a amp is suppose to simplify a signal and if it has a flat [quoted text clipped - 29 lines] > > > > In other words, "engineers please don't respond". Gotcha. > Hi, > [quoted text clipped - 4 lines] > leads me to believe that the MTX probably has larger capacitors and > Torodials. Believe it or not, one simple test that is often accurate is to weigh 2 different amps. The heavier one will usually sound better (or "perform" better, depending on how you define "perform".) Now, they could cheat, and make really heavy metal covers. But that would kind of defeat the purpose - they wouldn't put much extra money into the extra metal unless the amp was better to begin with. Manufacturers (especially cheesy ones) manipulate the specs on their amps so much that I'd go so far as to say you will get a more accurate picture of which amp sounds better by weighing them than by looking at the usual specs! (let the flames begin) "Believe it or not, one simple test that is often accurate is to weigh 2 different amps. The heavier one will usually sound better (or "perform" better, depending on how you define "perform".)" I'd be really interested in hearing your explanation of this. Tony  SignatureEclipse CD8454 Head Unit, Phoenix Gold ZX475ti, ZX450 and ZX500 Amplifiers, Phoenix Gold EQ-232 30-Band EQ, Dynaudio System 360 Tri-Amped In Front and Focal 130HCs For Rear Fill, 2 Soundstream EXACT10s In Aperiodic Enclosure > >> Hi, [quoted text clipped - 22 lines] > specs! > (let the flames begin) > "Believe it or not, one simple test that is often accurate is to weigh 2 > different amps. The heavier one will usually sound better (or "perform" > better, depending on how you define "perform".)" > > I'd be really interested in hearing your explanation of this. His explanation was that companies often don't put more metal into an amp than they have to. This isn't terribly far off the mark, but it's hardly a reliable indicator either. But I think his last sentence summed it up: "Manufacturers (especially cheesy ones) manipulate the specs on their amps so much that I'd go so far as to say you will get a more accurate picture of which amp sounds better by weighing them than by looking at the usual specs!" That's a valid argument. It comes down to - which is worse? Going by the specs or going by the weight? > "Believe it or not, one simple test that is often accurate is to weigh 2 > different amps. The heavier one will usually sound better (or "perform" > better, depending on how you define "perform".)" > > I'd be really interested in hearing your explanation of this. MZ said it, but so did Trader to begin with. Check out this review of *good* home amplifiers. These are in the $10,000 range. Search for the word "weight" and read the whole paragraph. The amp that weighs 10 lbs more costs $1,000 more. It is the "high performance" version of the amp. But note to begin with that these are expensive amps, and they weigh over 100 pounds. So it goes. http://www.soundstage.com/revequip/accusticarts_amp_iiachp.htm Like I said to begin with, believe it or not, weight is a pretty decent indicator of quality (including power output and headroom.) Of course, we're not talking about tube amps here. > Like I said to begin with, believe it or not, weight is a pretty decent > indicator of quality (including power output and headroom.) Of course, we're > not talking about tube amps here. Having said that, check out this. Again, search on "weight" http://www.stereophile.com/amplificationreviews/875/ Heh heh. Well I agree with everything you wrote. However, there are many here who believe that amps all sound the same. This doesn't make sense because how could an amp with a superior circuit design and premium parts sound the same as a RadioShack special. I've personally have auditioned many amps on my Klipschorns and can testify that all amps don't sound the same. I don't buy into the theory that distortion is what I'm hearing because even at moderate levels I can hear a substantial difference. I'm sure that some speakers are not revealing enough to hear much of a difference but with Klipschorns you hear everything that is present. My Father in-law is an engineer and he has a cheap Bose system and it sounds like sh.t. He laughed when I bought a tube amp for my Klipschorns and thought that it couldn't possibly sound good. Well it sounded amazing although I still prefer my SS amp. But yeah believe what you want and buy the low-end gear if it makes you happy. >> Like I said to begin with, believe it or not, weight is a pretty decent >> indicator of quality (including power output and headroom.) Of course, [quoted text clipped - 4 lines] > http://www.stereophile.com/amplificationreviews/875/ > Heh heh. > Well I agree with everything you wrote. However, there are many here who > believe that amps all sound the same. That's not quite what we're telling you. We're telling you that two amps that *AREN'T CLIPPING* will sound the same. The reason for this is because even the worst amps don't present enough distortion or a poor enough frequency response to be distinguished. Especially when you consider that speakers, by their very nature, produce a huge amount of distortion and a screwy frequency response. And even moreso when we're talking about road noise and the poor listening conditions of a car. > This doesn't make sense because how > could an amp with a superior circuit design and premium parts sound the same > as a RadioShack special. Because the RadioShack special will reproduce the sound with literally no distortion. The technology is there to do it extremely cheaply. Sure, the amp may shut down when you push it, or it may be more prone to breaking, or it may only deliver half of what they claim it will deliver, but when it's actually working it will sound perfect. > I've personally have auditioned many amps on my > Klipschorns and can testify that all amps don't sound the same. You never did it under controlled conditions, so how do you know what to attribute the sound difference to? > I don't buy > into the theory that distortion is what I'm hearing because even at moderate > levels I can hear a substantial difference. What else could you be hearing? Distortion is, by definition, a deviation of the output signal with respect to the input signal. If there's no deviation of the signal, then it will move the speaker in the exact same way...therefore, it's impossible for a sound difference to occur. > I'm sure that some speakers are > not revealing enough to hear much of a difference but with Klipschorns you > hear everything that is present. My Father in-law is an engineer and he has > a cheap Bose system and it sounds like sh.t. The reason it sounds like sh.t is because the speakers are poor, the amplifier is clipping, and there's a substantial amount of signal processing going on. > He laughed when I bought a > tube amp for my Klipschorns and thought that it couldn't possibly sound > good. Well it sounded amazing although I still prefer my SS amp. But yeah > believe what you want and buy the low-end gear if it makes you happy. I don't expect anyone to "believe" anything. It's not generally wise to believe something that someone says for no good reason at all. If you really want the truth, then you have no other option but to learn how amplifiers work and then come to the conclusion yourself. I'd be more than happy to suggest some introductory electronics textbooks that will help you learn these things. After that, maybe you'd be able to bench test your own amps with no expense other than a good computer sound card. If there are so many variables then why even bring up the old argument that all amps sound the same? The fact is that in real world situations you usually get what you pay for. Given that at some price point the benefits are not significant to justify the extra dollars. I do understand how amplifiers work and specs don't always tell the true tale of what the consumer is buying or how it will sound. I don't believe you can measure, with instruments, how an amp will wound in the real world. It's like fine wine - you can measure the alcohol content of two fine wines but can you can't measure the fragrance and taste. I'll take my ears over your instruments any day. No offense but that is how I feel. Please come over with your Radio Shack amp and I will challenge you that I can spot the inferior amp - every time! Even at low listening levels. Cheap amps don't have the same revealing amplification as a well made amp. And it's not distortion that is the deciding factor. There are many other factors that your instruments can't measure. >> Well I agree with everything you wrote. However, there are many here who >> believe that amps all sound the same. [quoted text clipped - 59 lines] > help you learn these things. After that, maybe you'd be able to bench > test your own amps with no expense other than a good computer sound card. > If there are so many variables then why even bring up the old argument that > all amps sound the same? Because it dispels the many myths out there that revolve around the notion that amplifiers have a "sonic signature". It points out that comments attributing one type of sound to amplifiers made by one company, and another type of sound to another company, have no basis in fact. > The fact is that in real world situations you > usually get what you pay for. Given that at some price point the benefits > are not significant to justify the extra dollars. This is exactly true, within limits. While it's true that oftentimes spending more on an amplifier will get you better reliability, better support, and usually more power, sometimes the "get what you pay for" doctrine doesn't hold true. For example, there's absolutely no reason to spend $10k on an amp. But some people do it - at least in home audio. > I do understand how > amplifiers work and specs don't always tell the true tale of what the > consumer is buying or how it will sound. I don't believe you can measure, > with instruments, how an amp will wound in the real world. Why not? > It's like fine > wine - you can measure the alcohol content of two fine wines but can you > can't measure the fragrance and taste. The only reason we can't measure the fragrance and taste is because we haven't worked out the details of the human olfactory system. Very little is known about it, in fact - MUCH less than the other senses. We do, however, have a good idea about what aspects of sound humans can perceive differences, and we can easily translate these thresholds to electrical and acoustical measurements. Furthermore, we can in fact isolate the amplifier as the lone variable and perform basic tests challenging observers to tell the difference between two amplifiers. The key here is isolation of variables - making sure that the only difference is the amplifier. This requires careful level matching, assurances that both amplifiers are not clipping, and that the experiment is being performed double blind. You haven't done this, so quite frankly, this renders your own personal observations useless. I work in sensory neuroscience. I get a paycheck to investigate how people's senses work, and the underlying theme throughout all of what we know about human sensation is that the brain is NOT interested in accurate reproduction of our surroundings. It's interested in only those components that are important for survival, and in order to promote this goal, it's devised ways to actually distort incoming information to better suit the needs of the animal. The bottom line: you cannot always trust your senses - not only do they have the tendency to deceive you; they're actually DESIGNED to deceive you. As such, prior knowledge about the audio equipment that you're using, misconceptions between sound quality and accuracy, sound quality and loudness, etc. all lead to the perception that system A is superior to system B, even if no difference is actually present. This is why it's vital to remove these variables from the equation when you're performing the tests. > I'll take my ears over your > instruments any day. No offense but that is how I feel. Please come over > with your Radio Shack amp and I will challenge you that I can spot the > inferior amp - every time! Well, I don't have the time or desire to do it, obviously. But there's a fellow named Richard Clark who has offered a $10,000 amplifier challenge who will be more than willing to let you give it a try. Why not? If you genuinely believe that you can tell the difference and you can pick your amplifier out from the Radio Shack amplifier, you'll end up $10k richer. > Even at low listening levels. Cheap amps don't > have the same revealing amplification as a well made amp. And it's not > distortion that is the deciding factor. There are many other factors that > your instruments can't measure. You've made mention of this a few times, but never elaborated. What is it that instruments can't measure that could be responsible? Of all the questions I've asked you, this is the one I'd really like to hear an answer for. > Because it dispels the many myths out there that revolve around the notion > that amplifiers have a "sonic signature". It points out that comments > attributing one type of sound to amplifiers made by one company, and > another type of sound to another company, have no basis in fact. See here is where we differ. I believe that amplifiers do have a sonic signature and it's not distortion that is present. I believe what I'm hearing is not measurable with instruments. All the amps I've tested have a flat response from 20 -20,000hz with in audible distortion at moderate listening levels. This would support my assumption that there are factors that can't be measured with instruments. This is the only way to explain how one amp can sound different then another. I don't buy that what I'm hearing is distortion. > This is exactly true, within limits. While it's true that oftentimes > spending more on an amplifier will get you better reliability, better > support, and usually more power, sometimes the "get what you pay for" > doctrine doesn't hold true. For example, there's absolutely no reason to > spend $10k on an amp. But some people do it - at least in home audio. Yes.. We agree here. At some price point you're paying for the name, esoteric goodies, and lots of overkill. These are the same people who probably buy Hummers to drive to the deli. > The only reason we can't measure the fragrance and taste is because we > haven't worked out the details of the human olfactory system. Very little [quoted text clipped - 4 lines] > and we can easily translate these thresholds to electrical and > acoustical measurements. There are parts of the brain and the universe that we will never understand or explain. Just because you can see a waverform on a LCD screen doesn't mean that there aren't nuances to that signal that you can't measure. We don't even know if all average humans hear alike. The human brain is unique to each person so wouldn't it make sense that not all humans can process outside stimuli in the same way. There are too many variable to make a blanket statement that all amplifiers sound the same when they are not clipping or producing distortion. It's like a microscope. If you look at a cell at 10x you don't see much but if you magnify it to 500x you can see more detail. Who's to say that you measurements are too crude to measure all that is inherant in an audio signal? Furthermore, we can in fact isolate the > amplifier as the lone variable and perform basic tests challenging > observers to tell the difference between two amplifiers. The key here is [quoted text clipped - 3 lines] > double blind. You haven't done this, so quite frankly, this renders your > own personal observations useless. I've heard of these tests, but any blind listening test would be flawed because humans don't process the same information in the same way from person to person. I have friends who are happy with a boombox and take them to a high-end stereo store and they still don't get it. I've done my own listening tests that were very accurate and my conclusions are much different then yours. There are also millions of stereo enthusiasts that would agree with me. Have you actually done your own testing. > I work in sensory neuroscience. I get a paycheck to investigate how > people's [quoted text clipped - 6 lines] > your senses - not only do they have the tendency to deceive you; they're > actually DESIGNED to deceive you. This is all theory and while it sounds great how can you prove it and make it a fact. The simple fact is that you can't. We think this is true but...........I'm sure there are scientists, in your field, that dispute your above statement and have their own research to support their own theories. So basically what your saying is that our need for survival has also distorted the incoming stimuli. Wouldn't that mean that you scientificvally measure this distortion caused by the human brain and this is just one more variable that is under your radar? > audio equipment that you're using, misconceptions between sound quality > and accuracy, sound quality and loudness, etc. all lead to the perception > that system A is superior to system B, even if no difference is actually > present. This is why it's vital to remove these variables from the > equation when you're performing the tests. Agreed. I've sone all this in my tests. I have a preamp that can make two amps output match. Did I have a sound meter no but from my tests I'm still a believer. > Well, I don't have the time or desire to do it, obviously. But there's a > fellow named Richard Clark who has offered a $10,000 amplifier challenge > who will be more than willing to let you give it a try. Why not? If you > genuinely believe that you can tell the difference and you can pick your > amplifier out from the Radio Shack amplifier, you'll end up $10k richer. Clark's test is very controversial and not the end all in this debate. How revealing was the speakers he was using? How revealing and different were the amps he was using? Who were the testers who took his challenge and why should they be chosen for critical listening? Too many variable to make this test reliable. I go by what my ears tell me not what some guy says who wants to be controversial and make a name for themselves. >> Even at low listening levels. Cheap amps don't >> have the same revealing amplification as a well made amp. And it's not [quoted text clipped - 6 lines] > questions I've asked you, this is the one I'd really like to hear an > answer for. How do you measure love, or the felling of how a child makes you feel or someone's faith. There are just some things in life we will not understand or will not be measurable. > > Because it dispels the many myths out there that revolve around the notion > > that amplifiers have a "sonic signature". It points out that comments [quoted text clipped - 4 lines] > signature and it's not distortion that is present. I believe what I'm > hearing is not measurable with instruments. But what is it? Do you not agree that if the waveform produced by amplifier A perfectly matches the waveform produced by amplifier B, there will be no difference in sound? > All the amps I've tested have a > flat response from 20 -20,000hz with in audible distortion at moderate > listening levels. This would support my assumption that there are factors > that can't be measured with instruments. Or it would support my assertion that the differences are not due to the amplifier, but rather due to some other aspect of the test. > > The only reason we can't measure the fragrance and taste is because we > > haven't worked out the details of the human olfactory system. Very little [quoted text clipped - 8 lines] > or explain. Just because you can see a waverform on a LCD screen doesn't > mean that there aren't nuances to that signal that you can't measure. Yes, it DOES mean that there aren't nuances that you can't measure. The resolution of modern day test equipment is extremely good. Certainly better than the thresholds of human hearing. If the test equipment doesn't reveal a difference, then a difference does not exist. There aren't unknown parameters to measure. Speakers operate on voltage and current, and nothing else. > We > don't even know if all average humans hear alike. The human brain is unique > to each person so wouldn't it make sense that not all humans can process > outside stimuli in the same way. No one has ever exhibit superhuman abilities such that they can hear the tiniest of differences, see with microscopic precision, or smell a cup of coffee 5 miles away. While there is indeed a substantial amount of variablity between people, there's probably much less than you realize and certainly much less than what would be responsible for detecting the differences in signal that we've measured between two amplifiers. > There are too many variable to make a > blanket statement that all amplifiers sound the same when they are not > clipping or producing distortion. It's like a microscope. If you look at a > cell at 10x you don't see much but if you magnify it to 500x you can see > more detail. Who's to say that you measurements are too crude to measure > all that is inherant in an audio signal? Because the measurements are made with nanovolt and microsecond resolutions. Humans can't detect differences that small. > I've heard of these tests, but any blind listening test would be flawed > because humans don't process the same information in the same way from [quoted text clipped - 3 lines] > different then yours. There are also millions of stereo enthusiasts that > would agree with me. Have you actually done your own testing. Yes, I have actually done my own testing. Anyway, blind testing is essential because it removes an extra stimulus from the equation - that is, it doesn't allow prior knowledge to enter into the decision. It's like taking the pepsi challenge. If you already have a preconceived notion that you like Pepsi better than Coke, then you need to remove knowledge of which can is Pepsi and which can is Coke in order to accurately measure which one you like better. You don't agree with this? > This is all theory and while it sounds great how can you prove it and make > it a fact. The simple fact is that you can't. No, it's not all theory. It's the result of years of carefully conducted scientific observation. > We think this is true > but...........I'm sure there are scientists, in your field, that dispute > your above statement and have their own research to support their own > theories. Quite frankly, there aren't. What I said was one of the central tenets of neuroscience. I can't think of a single notable scientist that believes otherwise. It's clear as day when you simply acknowledge the strategies that even the sensory apparatus themselves are engaging in to transduce the stimulus into a neural code. > So basically what your saying is that our need for survival has > also distorted the incoming stimuli. Wouldn't that mean that you > scientificvally measure this distortion caused by the human brain and this > is just one more variable that is under your radar? I'm saying, by definition, your brain is transforming incoming information to better suit its purposes. The human visual system, for example, is not a spectrophotometer. It does not have a flat response across all wavelengths (you've only got a few hundred nanometers of range to play with). It does not have the ability to distinguish between two points of light separated by a nanometer. It does not have the ability to distinguish between two flashes a nanosecond apart. These are nonlinearities of the visual system, hence, by definition, distortion. Moreover, even at the level of the human retina, you're not seeing a faithful reproduction of the stimulus being captured by the neural code. Adaptation effects, center-surround effects, and the density of photoreceptors being a function of eccentricity make sure of this. So an accurate signal isn't even getting to your brain. Surely, this shouldn't be surprising to you, right? After all, you can't see ultraviolet light, can you? And you can't see the details of a mountaintop from 10 miles away, right? > > audio equipment that you're using, misconceptions between sound quality > > and accuracy, sound quality and loudness, etc. all lead to the perception [quoted text clipped - 5 lines] > amps output match. Did I have a sound meter no but from my tests I'm still > a believer. You didn't double blind your tests. You didn't measure the output level of the amps to test that they were truly level-matched. And you didn't ensure that the amps were not clipping. Your tests don't hold up. > > Well, I don't have the time or desire to do it, obviously. But there's a > > fellow named Richard Clark who has offered a $10,000 amplifier challenge [quoted text clipped - 4 lines] > Clark's test is very controversial and not the end all in this debate. How > revealing was the speakers he was using? His conditions stipulate that you can use any speakers you want. > How revealing and different were > the amps he was using? His conditions stipulate that you can use any solid state amplifiers you want, as long as they're not broken. > Who were the testers who took his challenge and why > should they be chosen for critical listening? Whoever asks to try. You should give it a shot. At least contact him to find out more information. It may be worth 10 grand for you. > > You've made mention of this a few times, but never elaborated. What is it > > that instruments can't measure that could be responsible? Of all the [quoted text clipped - 4 lines] > someone's faith. There are just some things in life we will not understand > or will not be measurable. We can measure audible perception rather flawlessly. You're just ignorant of the studies that do so, never having done them yourself or read any of the original papers by the folks that do them. Nor have you built, designed, bench-tested, or taken the time to learn in depth how amplifiers (the topic of this discussion) work. That's ok. I probably wouldn't have any idea about the intricacies of your profession either, even if it was my hobby. > > > Because it dispels the many myths out there that revolve around the notion > > > that amplifiers have a "sonic signature". It points out that comments [quoted text clipped - 8 lines] > amplifier A perfectly matches the waveform produced by amplifier B, there > will be no difference in sound? Of course. Unfortunately, they don't measure as accurately as you think they do. > > > > Because it dispels the many myths out there that revolve around the notion > > > > that amplifiers have a "sonic signature". It points out that comments [quoted text clipped - 11 lines] > Of course. Unfortunately, they don't measure as accurately as you think they > do. That didn't make much sense out of context of Trader's remark. When he said what he's hearing isn't "measurable", I don't really know what he means. What I mean is that it is measurable, of course - for example, human ears can hear it. That's not the same thing as saying current tools *are* measuring it. That's the problem. It certainly *can* be meausured, and some day maybe it will be. That will be nice. > > But what is it? Do you not agree that if the waveform produced by > > amplifier A perfectly matches the waveform produced by amplifier B, there > > will be no difference in sound? > > Of course. Unfortunately, they don't measure as accurately as you think they > do. Yes they do. Today's modern test equipment is extremely precise. Much more precise than our senses. It can introduce a virtually nonexistent impedance (thank goodness for op amps) and has an error of measurement far below what you think it is. The error is usually listed in the manual or on the back of the machine itself. > > > But what is it? Do you not agree that if the waveform produced by > > > amplifier A perfectly matches the waveform produced by amplifier B, there [quoted text clipped - 8 lines] > below what you think it is. The error is usually listed in the manual or > on the back of the machine itself. No, you still don't get it. You still think, for example, that because we can detect parts per billion, that scientific measuring devices are more precise than our tongue and nose. It's not a question of precision, it's a question of accuracy. Those tools are not measuring the same way we're measuring. It's too complicated. The wine example was a good one. Even though they can do a chemical analysis on it, they still can't determine which blend of tastes and smells will make up a good wine and which will taste best. Sure, they can detect obvious things like spoilage or the presence of some awful chemical, but they can't figure out which wine would be preferred in a blind tasting. > > Yes they do. Today's modern test equipment is extremely precise. Much > > more precise than our senses. It can introduce a virtually nonexistent [quoted text clipped - 11 lines] > detect obvious things like spoilage or the presence of some awful chemical, but > they can't figure out which wine would be preferred in a blind tasting. But what you're failing to grasp here is that we're not trying to classify perception in and of itself. This discussion is not addressing which forms of distortion are less pleasing than others, and what the underlying neural mechanisms are to explain it. The discussion is much simpler than that - it is whether or not it can be detected in two independent samples. Or, more precisely, what is the "just noticable difference"? So, using your wine example, we're not interested in which wine is more fruity. We're interested in whether or not you can tell the difference between wine A and wine B, and how test equipment compares in the ability to detect the difference. Are you still claiming that we're able to detect differences (not the quality of the difference, but the difference itself) that test equipment cannot? If you dropped 10 molecules of something into the glass, would you be able to detect it with your senses? Would the test equipment? Again getting back to audition, I think the answer is more clearcut. It's common knowledge that we can measure sounds with sensitive microphones that simply aren't loud enough for humans. It's also common knowledge that we can measure harmonic distortion down to millionths of a percent with test equipment, but we can't make the distinction with our ears. It's also common knowledge that you can use an SPL meter to tell the difference between a sound that's 80.000dB and a sound that's 80.001dB, but the best a human can do is roughly in the 0.5dB range broadband. It's also well known that humans have a greater difficulty perceiving a narrowband dip in frequency response than a narrowband boost in frequency response, whereas test equipment has no such difficulty. We also know that masking can prevent things from being heard - test equipment does not experience this phenomenon. Not only is there demonstrable evidence pointing to the fact that test equipment can beat all of our sensory modalities (in terms of detection!), but it's also common knowledge. > Are you still claiming that we're able to detect differences > (not the quality of the difference, but the difference itself) that test > equipment cannot? If you dropped 10 molecules of something into the glass, > would you be able to detect it with your senses? Would the test equipment? OK, well some test equipment can, and some can't. Whether the test equipment exists today that is good enough to tell what I can tell with my ear is one question (I don't know whether it exists or not.) Whether that is the test equipment that is actually used to do a review is another thing. (I'm sure some reviews have been done with cheaper, less accurate equipment.) > Again getting back to audition, I think the answer is more clearcut. It's > common knowledge that we can measure sounds with sensitive microphones that > simply aren't loud enough for humans. Right. > It's also common knowledge that we > can measure harmonic distortion down to millionths of a percent with test > equipment, but we can't make the distinction with our ears. It's also > common knowledge that you can use an SPL meter to tell the difference > between a sound that's 80.000dB and a sound that's 80.001dB, but the best a > human can do is roughly in the 0.5dB range broadband. OK, but again - that is what is *possible* (I'm just taking your word for it.) I can assure you that that is not the equipment that is being used for most reviews (or at least has been used in the past.) It's either because such equipment is just too expensive, or too difficult to use correctly, or maybe even because the reviewer already believes such precision isn't relevant. > Not only is there demonstrable evidence pointing to the fact that test > equipment can beat all of our sensory modalities (in terms of detection!), > but it's also common knowledge. But it's not common practice. > OK, well some test equipment can, and some can't. Whether the test equipment > exists today that is good enough to tell what I can tell with my ear is one > question (I don't know whether it exists or not.) Whether that is the test > equipment that is actually used to do a review is another thing. (I'm sure some > reviews have been done with cheaper, less accurate equipment.) It depends what you refer to when you say "what I can tell with my ear". If you're referring to detection of harmonic distortion, detection of noise, or detection of IMD, then I can tell you with certainty that we've long had the test equipment to be able to perform such simple measures. In fact, all you need is a high quality microphone to capture the signal, and the analysis can be done on any PC (with free software, no less!). But if instead you mean whether or not we have test equipment to detect the mood of someone's voice, to detect a voice as someone you know under all conditions (eg. even when their voice is altered because they have a cold, etc), or to translate a voice into speech, then no, the human brain is still superior to test equipment. But again, I'm not talking about determining which sound is better, more musical, warmer, brighter, smoother, realistic, etc. I'm simply referring to whether or not one can detect a difference under a controlled setting. As for the equipment that's used to bench amps, nothing terribly expensive or elaborate is required. In recent years, I've used expensive data acquisition cards to do that sort of thing. I've used simpler USB data acquisition devices. And, even more recently, I've used a good sound card's input, a homemade attenuator, and some custom written matlab software to do it. People who benchtest for a living undoubtedly use more sophistocated equipment, but it's not necessary IMO. In short, you can get incredibly precise equipment for extremely low prices. Hell, Arny Krueger benches soundcards WITH a soundcard, and his tests are among the most comprehensive available! When you can hook up test equipment to the human brain then you will have an instrument that can measure sound the way we perceive it. Test equipment can't hear-test equipment doesn't have ears. Test equipment can measure and take the sound waves and turn it into electronic impulses to be read on a screen and then subjectively analyzed. You will never have a machine that can tell you what a wine tastes like. Unless you can hook it into a human brain. My point is that your electronic waveform is not telling the whole story. I agree that my tests were not ideal and I did know the amps involved. In fact, I wanted to like the amp I thought lacked the ability to allow my human ears hear all there is to hear in the upper octaves of the music I used for my tests. This guy Clark can claim anything he wants. Is he a scientist doing controlled experiments. Not likely just some guy trying to make a name for themselves. Science is mostly theory. There is not much fact to science. Scientist do research and complete studies and can come to a reasonable conclusion but most of what they do is theory and can usually be challenged by another researcher with their own theories. Who is to say all humans hear or see the same exact way. We just don't know. We certainly know that not all human taste food the same because there are people who have their favorites which may be your most hated foods. >> Are you still claiming that we're able to detect differences >> (not the quality of the difference, but the difference itself) that test [quoted text clipped - 44 lines] > > But it's not common practice. > When you can hook up test equipment to the human brain then you will have an > instrument that can measure sound the way we perceive it. Test equipment > can't hear-test equipment doesn't have ears. Test gear cannot duplicate the BAD things involved in human hearing like predjudice, or lack of high frequency response that some folks have or DEAFNESS.... ;-) But test gear for audio is FAR more accurate than a humans perception... If you can hear the difference it can be measured!!! But, some folks IMAGINE that they hear differences when no differences really exist, those of course cannot be measured!! Not differences in HOW YOU HEAR, but differences in the sounds you hear.... > You will never have a machine that > can tell you what a wine tastes like. Im not aware of test equipment that measures tastes, and if there were any, I would not be prepared to compare its accuracy to that of audio test gear...Which BTW I am very familiar with... I can measure sound differences that folks CANNOT HEAR but I have never seen a LEGITIMATE sound difference that someone can actually hear that I cannot measure,,... And isnt this getting off the point about amps sounding different? Those that think they do are either not conducting the tests correctly OR being influenced by other variables.... > Science is mostly theory. There is not much fact to science. Not in my science textbooks... I have LOTS of facts... Thats the basis of SCIENCE!! You must be confused with SCIENCE FICTION!! ha ha Eddie Runer installin since 1974 http://www.installer.com/tech/ > When you can hook up test equipment to the human brain then you will have an > instrument that can measure sound the way we perceive it. Test equipment [quoted text clipped - 4 lines] > brain. My point is that your electronic waveform is not telling the whole > story. I understand what your point is. However, it's incorrect. The sound wave is being captured by the device. It is being transduced from mechanical energy (that's what a sound wave is) to electrical energy. The output is then sent on to a machine to be analyzed. Now, I bet you're thinking that I'm talking about a microphone. But I'm talking about the ear! It behaves in essentially the same way that a microphone behaves (but, instead of using Faraday's law, it uses ion channels triggered by movement of hair cells). So the microphone is using the same exact piece of information to make its measurement (compression and rarefaction of air molecules). Therefore, it can't possibly have more information available to it than the microphone. So, in light of this explanation, how could it not be telling the whole story? > Science is mostly theory. There is not much fact to science. Not sure what this means. We derive facts from logic. Science is applied logic. > Scientist do > research and complete studies and can come to a reasonable conclusion but > most of what they do is theory and can usually be challenged by another > researcher with their own theories. Right. So I suggest you dig up just one researcher who believes that the ear works on something other than sound waves - or whatever it is you're suggesting. Frankly, I don't think you know what it is you're suggesting. > Who is to say all humans hear or see the same exact way. We just don't > know. Well, if you mean who is to say that all humans have the same abilities, they don't. This has been examined. There is of course a range of capabilities, and we know what it is. > We certainly know that not all human taste food the same because > there are people who have their favorites which may be your most hated > foods. You're getting confused. People do indeed have preferences. They like different kinds of sounds, different kinds of music. That doesn't mean that some people have different hearing capabilities because of it. The information getting TO the brain (that allows you to then make decisions about what you like and what you don't like) is limited. And I've tried to explain to you that these limitations, while not identical in everyone, are in a certain range. And that range is far from the level that exists between the two amplifiers. > So the microphone is using the same exact piece of information to make its > measurement (compression and rarefaction of air molecules). Therefore, it > can't possibly have more information available to it than the microphone. > So, in light of this explanation, how could it not be telling the whole > story? The problem is not the information. The problem is the measurement of the information. First, you are not strictly correct - the microphone does not have the same information available to it, because it's not shaped like an ear. If it were, not all human ears are shaped the same. But that's not relevant. The real problem is that microphones are not perfect and can't send a perfect signal to be analyzed. There is always some distortion of the original signal. > > So the microphone is using the same exact piece of information to make its > > measurement (compression and rarefaction of air molecules). Therefore, it [quoted text clipped - 7 lines] > ear. If it were, not all human ears are shaped the same. But that's not > relevant. The pinna introduces distortion, actually. That's the point of it. It improves high frequency response for sounds coming in front of you (this is good) but intentionally blocks high frequencies for sounds coming behind you. As such, it assists the brain with localization. Importantly, it's also responsible for the brain's ability to estimate elevation of the source. You'll note that it's not symmetrical from top to bottom. Early auditory areas deep in the brain spend the bulk of their resources making these computations (the inferior colliculus perhaps the most prominent - anyway, not even having reached the cortex yet). This is an example of the auditory system, like all of the other sensory systems, intentionally introducing distortion into the signal in order to pull out attributes of the stimulus that are important for the animal to work. The visual system is probably even more guilty of employing this strategy. It's a common trend, all the way from humans to invertebrates. So yes, it's a GOOD THING that microphones don't use these tricks. We want accuracy, so ideally it will collect sounds from all directions equally. > The real problem is that microphones are not perfect and can't > send a perfect signal to be analyzed. There is always some distortion of > the original signal. But substantially less than the human auditory system introduces. Microphones tend to have a reasonably flat response from 20 to 20kHz (the good ones at least). The human auditory system has an awful response, peaking around 1kHz or less (the dominant part of human speech, incidentally) and responding poorly above 15kHz and below about 100Hz. Additionally, microphones have a cleaner transduction mechanism, not having to rely on a network of bones attached to an asymmetric diaphragm. Also, the auditory system inherently produces its own distortion known as otoacoustic emissions which are much more significant than distortion effects produced by decent microphones. Finally, and most importantly, the microphone is able to make an electrical measurement that's limited only by the inductance of the coil (which is why it's able to have such a great spectral range). The auditory system, however, relies on a network of neurons that are each tuned to relatively wide band of frequencies to encode the signal by essentially performing a rough fourier transform of the signal, and then, before the signal is even transmitted to the brain, computations are performed to essentially subtract adjacent frequencies from each other (a form of lateral inhibition - another bit of distortion added to the system). As a result, the signal being sent to the brain is a far cry from the signal that reached the ear drum. In short, microphones do a much better job at capturing the original signal than does the human auditory system. Not only because it uses more precise materials and mechanisms, but also because it's designed for perfect reproduction - the auditory system is not. Mark, You obviously know way too much about how the human ear and testing devices actually work to be productive in this discussion. Here you are providing scientific evidence and displaying a strong understanding of the subject matter. Noone wants that, we want conspiracy theories about test equipment and talk about magical and mysterious unknowns that we can all perceive in different ways. That way noone can ever be wrong and everyone can be right! Get it together. (Note for the readers who are unable to detect sarcasm. The above paragraph is dripping with it, there is so much of it that right now it should be leaking out your computer's open ports. I now return you to your regularly scheduled flame-war.) Les > > > So the microphone is using the same exact piece of information to make its > > > measurement (compression and rarefaction of air molecules). Therefore, it [quoted text clipped - 57 lines] > precise materials and mechanisms, but also because it's designed for > perfect reproduction - the auditory system is not. >Noone wants that, we want conspiracy theories about test equipment > and talk about magical and mysterious unknowns that we can all perceive in > different ways. The only one talking about "mysterious unknowns" is you. I certainly haven't mentioned any. Every word you say is based on mysterious unknowns! > The only one talking about "mysterious unknowns" is you. I certainly haven't > mentioned any. has anyone heard the sound of a UFO? Or measured the sound qualities of the Holly Grail? > Mark, > [quoted text clipped - 12 lines] > > Les > > > So the microphone is using the same exact piece of information to make its > > > measurement (compression and rarefaction of air molecules). Therefore, it [quoted text clipped - 13 lines] > want accuracy, so ideally it will collect sounds from all directions > equally. When I said "it's not relevant", what didn't you understand? > > The real problem is that microphones are not perfect and can't > > send a perfect signal to be analyzed. There is always some distortion of > > the original signal. > In short, microphones do a much better job at capturing the original > signal than does the human auditory system. Not only because it uses more > precise materials and mechanisms, but also because it's designed for > perfect reproduction - the auditory system is not. Completely beside the point. Whether the microphone hears the sound or the ear does isn't the point. The point is that microphones aren't perfect, period. "Designed for perfect reproduction" is completely irrelevant. It's doesn't work perfectly. > > In short, microphones do a much better job at capturing the original > > signal than does the human auditory system. Not only because it uses more [quoted text clipped - 5 lines] > "Designed for perfect reproduction" is completely irrelevant. It's doesn't work > perfectly. No, the POINT is that microphones are better than your ears. Period. I've tried to explain this to you in every way I can, going so far as to explain how microphones and the auditory system both work and what their limitations are. Yet you still cling to the notion that the human auditory system is more precise. This, coming from someone who's never built or played around with microphones, and someone who isn't active in the human sensory system research community. > > > In short, microphones do a much better job at capturing the original > > > signal than does the human auditory system. Not only because it uses [quoted text clipped - 15 lines] > are. Yet you still cling to the notion that the human auditory system is > more precise. No, you cling to mistaken notion that precion has anything to do with this problem. I suggest you read up on the actual problem, rather than spouting off about the precision of measuring equipment. > > No, the POINT is that microphones are better than your ears. Period. I've > > tried to explain this to you in every way I can, going so far as to explain [quoted text clipped - 5 lines] > problem. I suggest you read up on the actual problem, rather than spouting off > about the precision of measuring equipment. Why are you changing your tune? You've attempted to refute my point that the measured distortion is low by claiming that the test equipment is less accurate than the auditory system. I've therefore addressed that silly assertion of yours and demonstrated that it's untrue. > > > are. Yet you still cling to the notion that the human auditory system > is [quoted text clipped - 9 lines] > accurate than the auditory system. I've therefore addressed that silly > assertion of yours and demonstrated that it's untrue. No, you said it's more PRECISE. Why are you blathering on and on when you can't tell the difference between accuracy and precision? Why are you ignoring me every single time I tell you this? I can tell you're not stupid. But you're stubborn, and you're dead set on "proving" me wrong, even though you can't find anything to prove to me that I don't already know. You're on a witch hunt, hoping to find some audiophile with "mystical assertions." I'm sorry I can't be that person for you, but maybe they have pay phone services where you can indulge your fantasies. In the mean time, if human ears can't tell the difference between live sound and stereo reproduced sound, then all the testing equipment and precision in the world is irrelevant. If human ears can (and almost all the time they can), then again testing equipment is irrelevant. Now if these differences are due to amplification (which they often are, at least in part), it's because of distortion of some sort. There are actually many links in the reproduction process, and distortion is added at every single step. (This distortion can be cumulative. For example, if we had some reproduction system where every step in the process reduced the amplitude by .1 dB, then after 10 or so iterations of this we'd have a noticeable (by the human ear) difference in amplitude.) Now if the human ear can hear distortion and measuring equipment can't, then there's something wrong with the measuring equipment, user or technique. So far I hope I haven't said anything you'd disagree with, even though you're chomping at the bit to do so. Now, why exactly is it so important for you to believe that a person can not hear any difference between 2 amps? What cornerstone of science will crumble to the ground for you if this is so? You agree (now) that all amplifiers exhibit distortion. What exactly is so hard to swallow when it can be heard? It happens, and it's measurable (at least in theory) by machines. If I can hear a difference between 2 amplifiers and it isn't being measured, then there's a problem with the measurement, not with me. If the measuring equipment is good enough, then the same problem will show up. What is so hard to swallow about that? > > Why are you changing your tune? You've attempted to refute my point that > > the measured distortion is low by claiming that the test equipment is less [quoted text clipped - 3 lines] > No, you said it's more PRECISE. Why are you blathering on and on when you can't > tell the difference between accuracy and precision? I can tell the difference, and I can tell you that the auditory system is neither accurate nor precise. But precision is what we're interested in here because we're interested in ddetectability, not the noise in the system (both of which, by the way, are higher in the auditory system than on computer screens). > Why are you ignoring me > every single time I tell you this? I can tell you're not stupid. But you're > stubborn, and you're dead set on "proving" me wrong, even though you can't find > anything to prove to me that I don't already know. The following are five things that you don't know but argue against despite the overwhelming evidence that has been presented to you: 1) that test equipment is more precise (and more accurate) than the human auditory system. 2) distortion measurements between any two car audio amplifiers behaving linearly are lower than the distortion thresholds that can be perceived by humans within the same context. 3) the human auditory system intentionally distorts the incoming signal to better suit its needs, and this distortion is higher than the distortion that a microphone introduces into the signal. 4) people who have published papers on human psychophysics and have benched amplifiers tend to know how to read their instruments, and therefore, there isn't an epidemic of fabricated data in those fields. 5) controls are important to implement in any test because it allows you to isolate variables and therefore assign relationships between the observations and the remaining variables - as such, you cannot pick and choose which of the variables to assign the observation to. > In the mean time, if human ears can't tell the difference between live sound and > stereo reproduced sound, Who said that? >then all the testing equipment and precision in the > world is irrelevant. If human ears can (and almost all the time they can), then [quoted text clipped - 5 lines] > the process reduced the amplitude by .1 dB, then after 10 or so iterations of > this we'd have a noticeable (by the human ear) difference in amplitude.) Finally we agree on something. > Now if the human ear can hear distortion and measuring equipment can't, then > there's something wrong with the measuring equipment, user or technique. Agreed. > So far > I hope I haven't said anything you'd disagree with, even though you're chomping > at the bit to do so. Now, why exactly is it so important for you to believe > that a person can not hear any difference between 2 amps? What cornerstone of > science will crumble to the ground for you if this is so? What are you talking about? > You agree (now) that > all amplifiers exhibit distortion. I always have. I've already dug up one quote to verify this. Must I google back to the more distant past to try to find even more evidence? A single quote (whose sole purpose was to clarify my terms) should suffice, no? > What exactly is so hard to swallow when it > can be heard? It happens, and it's measurable (at least in theory) by machines. > If I can hear a difference between 2 amplifiers and it isn't being measured, > then there's a problem with the measurement, not with me. You haven't yet performed this test, even though you think that you have (see #5 above). And, as I've said at the beginning of the discussion, if you can demonstrate that you can hear the difference, then you should publish your results. They would indeed be groundbreaking. > > > Why are you changing your tune? You've attempted to refute my point > that [quoted text clipped - 10 lines] > neither accurate nor precise. But precision is what we're interested in > here because we're interested in ddetectability, not the noise in the system The auditory system is by definition 100% accurate, if not very precise. That is the only reasonable definition of accuracy when it comes to making sounds we're going to listen to. > > Why are you ignoring me > > every single time I tell you this? I can tell you're not stupid. But [quoted text clipped - 7 lines] > 1) that test equipment is more precise (and more accurate) than the human > auditory system. Test equipment is more precise but not accurate. > 2) distortion measurements between any two car audio amplifiers behaving > linearly are lower than the distortion thresholds that can be perceived by > humans within the same context. Ah, "behaving linearly". > 3) the human auditory system intentionally distorts the incoming signal to > better suit its needs, and this distortion is higher than the distortion > that a microphone introduces into the signal. Irrelevant. The distortion is different, but no matter. It still exists. And distortion is cumulative. > 4) people who have published papers on human psychophysics and have benched > amplifiers tend to know how to read their instruments, and therefore, there > isn't an epidemic of fabricated data in those fields. So that proves that the amplifiers they tested work within the limits of their test equipment. > 5) controls are important to implement in any test because it allows you to > isolate variables and therefore assign relationships between the > observations and the remaining variables - as such, you cannot pick and > choose which of the variables to assign the observation to. Obviously controls are important. What's interesting is how you throw the whole scientific process out the window out of desperation to prove me wrong (for whatever reason know only to you.) For example, how could you possibly know what controls were used? Why would you make any such assumptions? I hope you don't make those sorts of assumptions when doing actual important work. > > So far > > I hope I haven't said anything you'd disagree with, even though you're [quoted text clipped - 6 lines] > > What are you talking about? I think my question was pretty clear. > > You agree (now) that > > all amplifiers exhibit distortion. > > I always have. Your quote early in this thread was to the contrary. So we're past it - you goofed, started backpedaling, now claim you've said it all along. Fine. I believe you actually mean it. > Must I google > back to the more distant past to try to find even more evidence? A single > quote (whose sole purpose was to clarify my terms) should suffice, no? No, not when it contradicted the one I gave. Let's move on, shall we? > > What exactly is so hard to swallow when it > > can be heard? It happens, and it's measurable (at least in theory) by [quoted text clipped - 5 lines] > You haven't yet performed this test, even though you think that you have > (see #5 above). How would you possibly be able to determine that from where you are? > > I can tell the difference, and I can tell you that the auditory system is > > neither accurate nor precise. But precision is what we're interested in [quoted text clipped - 3 lines] > is the only reasonable definition of accuracy when it comes to making sounds > we're going to listen to. Wrong. Accuracy, by definition, means that the output matches the input. The reference, therefore, is the sound wave. > > The following are five things that you don't know but argue against despite > > the overwhelming evidence that has been presented to you: > > 1) that test equipment is more precise (and more accurate) than the human > > auditory system. > > Test equipment is more precise but not accurate. Wrong. Test equipment is more accurate. That is, unless you're willing to take the position that all manufacturers are lying about the accuracy of their devices. So what accounts for this inaccuracy anyway? (note also that it's worth bringing up again the point I made about bypassing test equipment completely in order to arrive at the same results - you've ignored this repeatedly) > > 2) distortion measurements between any two car audio amplifiers behaving > > linearly are lower than the distortion thresholds that can be perceived by > > humans within the same context. > > Ah, "behaving linearly". Yes, in other words, not clipping. I've stipulated this aspect from the very beginning, and when into greater depth when Tony asked about it. > > 3) the human auditory system intentionally distorts the incoming signal to > > better suit its needs, and this distortion is higher than the distortion > > that a microphone introduces into the signal. > > Irrelevant. The distortion is different, but no matter. It still exists. And > distortion is cumulative. How could it be irrelevant when it's the topic of discussion? When we're discussing whether or not humans can perceive the distortion present in modern day amplifiers, it's essential to know how much distortion is present and what the distortion threshold is for humans. Knowing the distortion introduced by the auditory system is a key component to answering the latter question. > > 4) people who have published papers on human psychophysics and have benched > > amplifiers tend to know how to read their instruments, and therefore, there > > isn't an epidemic of fabricated data in those fields. > > So that proves that the amplifiers they tested work within the limits of their > test equipment. What do you mean by "work within the limits of their test equipment"? > > 5) controls are important to implement in any test because it allows you to > > isolate variables and therefore assign relationships between the [quoted text clipped - 5 lines] > whatever reason know only to you.) For example, how could you possibly know > what controls were used? You told me. > > > You agree (now) that > > > all amplifiers exhibit distortion. > > > > I always have. > > Your quote early in this thread was to the contrary. No, it wasn't. I provided a quote where I specifically said that all amplifiers exhibit distortion. You're either ignoring that or flat out lying. > So we're past it - you > goofed, started backpedaling, now claim you've said it all along. Fine. I > believe you actually mean it. I did say it all along. I provided evidence that you've apparently chosen to ignore. And I've said it in this very newsgroup for years. Long before you ever graced us with your presence. > > You haven't yet performed this test, even though you think that you have > > (see #5 above). > > How would you possibly be able to determine that from where you are? I've chosen to believe what you say. Shouldn't I? > > > I can tell the difference, and I can tell you that the auditory system > is [quoted text clipped - 10 lines] > Wrong. Accuracy, by definition, means that the output matches the input. > The reference, therefore, is the sound wave. There is no sound wave input. Sound requires some medium, such as air or water. > > > The following are five things that you don't know but argue against > despite [quoted text clipped - 8 lines] > take the position that all manufacturers are lying about the accuracy of > their devices. So what accounts for this inaccuracy anyway? The fact that they, like you, wouldn't know the difference between accuracy and precision until they Googled for it. > > > 2) distortion measurements between any two car audio amplifiers behaving > > > linearly are lower than the distortion thresholds that can be perceived [quoted text clipped - 4 lines] > > Yes, in other words, not clipping. Not exactly the same thing (there are other forms of liner distortion), but it still leaves out non-linear distortion! > > So that proves that the amplifiers they tested work within the limits of > their > > test equipment. > > What do you mean by "work within the limits of their test equipment"? It seems pretty obvious to me. Unless you're going to claim perfect testing equipment now. > > Obviously controls are important. What's interesting is how you throw the > whole [quoted text clipped - 5 lines] > > You told me. No, I didn't. > > Your quote early in this thread was to the contrary. > > No, it wasn't. Yes, it was. You said "Because the RadioShack special will reproduce the sound with literally no distortion." There aren't many interpretations of that you can use to weasel out of it. > I provided a quote where I specifically said that all > amplifiers exhibit distortion. You're either ignoring that or flat out > lying. I'm not ignoring it, I'm saying it contradicts what you wrote earlier. i.e. backpedaling. > > > You haven't yet performed this test, even though you think that you have > > > (see #5 above). > > > > How would you possibly be able to determine that from where you are? > > I've chosen to believe what you say. Shouldn't I? You haven't been given enough information. Which seems to be how you do all your testing and conclusions? > > Wrong. Accuracy, by definition, means that the output matches the input. > > The reference, therefore, is the sound wave. > > There is no sound wave input. Sound requires some medium, such as air or water. Yeah, hence the sound wave. It is the input to the system, whether the system is the microphone or the ear. > > Wrong. Test equipment is more accurate. That is, unless you're willing to > > take the position that all manufacturers are lying about the accuracy of > > their devices. So what accounts for this inaccuracy anyway? > > The fact that they, like you, wouldn't know the difference between accuracy and > precision until they Googled for it. I didn't google for it. It's common knowledge. Show me a website anywhere that describes the difference as I described it - as the deviation from the mean and sample mean, respectively. > > Yes, in other words, not clipping. > > Not exactly the same thing (there are other forms of liner distortion), but it > still leaves out non-linear distortion! In the field, when people refer to an amplifier "behaving linearly" they mean not clipping. I forgot that you weren't in the field, had no knowledge of the field, don't belong to any organizations in the field, and don't read any of the papers in the field. My mistake. > > > So that proves that the amplifiers they tested work within the limits of > > their [quoted text clipped - 4 lines] > It seems pretty obvious to me. Unless you're going to claim perfect testing > equipment now. No, your sentence is not coherent. Amplifiers working within the limits of the test equipment? > > > Obviously controls are important. What's interesting is how you throw the > > whole [quoted text clipped - 7 lines] > > No, I didn't. It was the topic of the post you made on Wednesday, November 17, 2004 2:22 PM. > > I provided a quote where I specifically said that all > > amplifiers exhibit distortion. You're either ignoring that or flat out > > lying. > > I'm not ignoring it, I'm saying it contradicts what you wrote earlier. i.e. > backpedaling. How could it be backpedaling when I've said in this newsgroup for years that amplifiers produce distortion? You're intentionally arguing semantics because you've realized your argument holds no water and you've already had 4 separate people call you out on it. > > > Wrong. Accuracy, by definition, means that the output matches the > input. [quoted text clipped - 5 lines] > Yeah, hence the sound wave. It is the input to the system, whether the > system is the microphone or the ear. We are talking about amplifiers. There is no sound input to an amplifier. Do you just enjoy pedantic arguments? > > The fact that they, like you, wouldn't know the difference between > accuracy and > > precision until they Googled for it. > > I didn't google for it. It's common knowledge. Riiiiiiiiiiight. Ho! Good one. > Show me a website anywhere > that describes the difference as I described it - as the deviation from the > mean and sample mean, respectively. Funny, the second one I found looks suspiciously like that. > > > Yes, in other words, not clipping. > > [quoted text clipped - 4 lines] > In the field, when people refer to an amplifier "behaving linearly" they > mean not clipping. Well duh! If the amplifier was behaving linearly, we'd be doing pretty darn well, wouldn't we? > > > > So that proves that the amplifiers they tested work within the limits > of [quoted text clipped - 9 lines] > No, your sentence is not coherent. Amplifiers working within the limits of > the test equipment? They work within the limits at which they can be tested. Is it hard work pretending not to understand what I say? > > I'm not ignoring it, I'm saying it contradicts what you wrote earlier. > i.e. > > backpedaling. > > How could it be backpedaling when I've said in this newsgroup for years that > amplifiers produce distortion? I don't know. It *could* be because you said "the RadioShack special will reproduce the sound with literally no distortion." > > Yeah, hence the sound wave. It is the input to the system, whether the > > system is the microphone or the ear. > > We are talking about amplifiers. There is no sound input to an amplifier. Do > you just enjoy pedantic arguments? Try to keep up. Me: "I can tell you that the auditory system is neither accurate nor precise. But precision is what we're interested in here because we're interested in ddetectability." You: "The auditory system is by definition 100% accurate." Me: "Wrong. Accuracy, by definition, means that the output matches the input. The reference, therefore, is the sound wave." So you're incorrect that the auditory system is 100% accurate. This has nothing to do with amplifiers. It has to do with the accuracy of the auditory system. > > Show me a website anywhere > > that describes the difference as I described it - as the deviation from the > > mean and sample mean, respectively. > > Funny, the second one I found looks suspiciously like that. Let's see a link. I asked you to show me. If you're making claims that I don't know what it means, even though I provided definitions, then the burden of proof is on you. > > > I'm not ignoring it, I'm saying it contradicts what you wrote earlier. > > i.e. [quoted text clipped - 6 lines] > reproduce the sound with literally no > distortion." Could it be that I specifically said that amplifiers produce distortion? I said this many times. I've said this for years. You're just too stubborn to admit that you're wrong. Instead you like to throw accusations at me that don't stick. You've proven to be disingenuous and too stubborn to see evidence that's staring you right in the face. 1. You accuse me of trying to portray amplifiers as not producing distortion. I provided evidence to you that I have never believed this to be true. You've ignored the evidence. 2. You accuse me of looking up the answer to your precision vs. accuracy question on google. You were unable to find any websites that offered the definition I offered. You stick by your outrageous claims. 3. You continually insist that the human auditory system is 100% accurate. It has been demonstrated to you that this isn't the case when I presented to you what the definition of accuracy is (it's funny that you didn't know the definition yourself, but you asked me the question anyway). You still adhere to your faulty notions. 4. Professionals in the field are trying to teach you how these devices work, which you've admittedly never constructed or designed yourself. Yet you refuse to listen, claiming you know more about it despite the fact that you've never delved into any of this before. That is the epitome of stubbornness - to refuse to learn even when faced with information that is new to you. 5. I've offered to back all of the claims I've made about the human auditory system with papers and texts in the field. You've offered no such backing with your rebuttals. That's sheer arrogance. > > > Show me a website anywhere > > > that describes the difference as I described it - as the deviation from [quoted text clipped - 4 lines] > > Let's see a link. I asked you to show me. Sorry, I left the link off by mistake. It was http://www.flatsurv.com/accuprec.htm By the way, your assertion that this is common knowledge is absolutely laughable. > > I don't know. It *could* be because you said "the RadioShack special will > > reproduce the sound with literally no > > distortion." > > Could it be that I specifically said that amplifiers produce distortion? No, that's not it. It's that you said "the RadioShack special will reproduce the sound with literally no distortion." as one of your very first posts in this thread. That's what gave me the insane notion that you might think amps can reproduce sound with literally no distortion. Call me crazy. > I said this many times. I've said this for years. You're j |
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