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I like that early on in the story, he hits on the difference between subjective experience and objective theory when it comes to the sonics of hi-fi amps. There

by beat 7y ago

I like that early on in the story, he hits on the difference between subjective experience and objective theory when it comes to the sonics of hi-fi amps. There's this thing that "objective" dudes on the internet think, and that's "If you can't measure it, it doesn't exist". They look at power, noise, and THD specs on an amp, and think that's it - that's the total explanation. In reality, there are things that plainly exist, but are not measured - either because they can't be measured economically, or we simply don't know how to measure them, or what it is we're measuring. So audio amps of similar specs can sound very different, and the one with the "bad" specs is often better than the "good" one. Another thing I learned about audio, which has been useful in general for engineering... marketing sells specs because specs look good, not because they're meaningful. I roll my eyes whenever I see "total harmonic distortion" ratings. It's like measuring how well a car drives 50mph. It's fine as a basic "this thing works" measure, but it's meaningless for sound quality.

dsr_ 7y ago
The difference between the subjective and objective schools is this: objective school: if we perform a high-N properly double-blinded ABX listening experiment, we can be confident that humans can either reliably tell a difference between A and B or cannot reliably distinguish between A and B. Once we establish a reliable difference, we can have informed individual opinions on whether A or B is better. subjective school: all experiments are worthless because every listener and every listening situation is unique.
- beat 7y ago
  You're misrepresenting both schools here. First, the "objective" school consists largely of internet loudmouths who have never done an actual A/B test. They're saying what seems intuitive to them, and imagining it's logical. Second, most serious subjectivists recognize the value of experiments and testing. Where they disagree with the would-be objectivists is that when their subjective experience disagrees with the test, they suspect the test might be wrong as well as the possibility that their subjective experience might be wrong. The so-called objectivists argue that when the test disagrees with the subjective experience, then the subjective experience must be purely imaginary. This perspective could be easily disproven with a test...
  - dsr_ 7y ago
    Somebody might be misrepresenting something here, yes. I especially like the way you managed to exactly explain the subjectivist viewpoint here while being completely fair to the objectivists.
    - beat 7y ago
      When it comes to sensory aesthetic experience, I don't think there's any such thing as a true objectivist. Acknowledging the limitations of scientific method for testing personal experience is itself a "subjective" thing, and any good scientist knows that when the results of one measurement disagree with another, it doesn't mean the other measurement is necessarily wrong. But I'm not talking about scientists or the scientific method here. I'm talking about dudes on the internet who claim they are "objective", which is a whole different horse.
      - dsr_ 7y ago
        You are continuing to make your point eloquently.
    - beat 7y ago
      Let's put it another way... subjectivist says that falling onto concrete hurts more than falling onto pillows. Objectivist says you're falling at the same speed either way, so the difference in pain must be your imagination.
sethhochberg 7y ago
Yes, mystery still remains in some parts of the audio world - in particular when we're talking about transducer theory, there are some aspects of loudspeaker and microphone performance that we can reliably characterize with derived equations, but where we still don't totally understand how those models translate back to the underlying physics fundamentals... but these are relatively specific edge cases in speaker design. Amplifiers and DACs have much less mystery about them - the math is solid, extremely well understood, and tested extensively in related fields like radar and sonar where the tolerances tighter and incentives for getting it right are stronger. Marketing absolutely drives specs (and especially specs without tolerances) when pushing gear, but that doesn't mean that the measurements are somehow invalid. Just expect the specs to tell you how close to the goal of a "wire with gain" you're getting, not to tell you specifically how the measured performance deviates from that goal. It also gets a lot more complicated when you're dealing with devices like headphones that have widely variable impedences - an amplifier that measures relatively flat into a medium-impedance load might fall apart when given dramatically higher or dramatically lower input impedance, and impedance matching is still a somewhat overlooked issue in the industry. The elephant in the room is always that some people just don't want to admit they think colored sound is better, so they convince themselves that there must be some aspect to audio performance that the science can't quantify - in reality, they're just avoiding quantifying a warm EQ curve, or nonlinear distortion, etc. I've studied audio electronics and DSP for audio at length, write plugins for audio software, have worked as a recording engineer, etc... and have no problem saying that mild nonlinear distortion and a bass boost sounds nice. The industry knows what "sounds good" and uses it to sell gear, but consumers think they want accuracy, so they get marketed to with terms like "transparency" or "resolution", and explain away unpleasant results with terms like "synergy" (or lack thereof).
- beat 7y ago
  Ok, since I brought up THD as a bad measurement, let's take a look at what, exactly, is being measured. A standard THD test measures harmonics generated from a sine wave at 1khz, into a resistive output load. So, how much does a 1khz sine wave represent an actual musical signal? And how much does a resistive load represent speaker impedance? The answers are "not at all", and "not at all". Do you see the problem yet? Of course you do. And that's the problem with amplifier specs. They're measuring what is easy to measure, not what reflects sonic behavior. And it gets worse, because it leads to designing for specs rather than designing for sonics. The easiest way to get "low distortion" spec-wise in an amp is large amounts of global negative feedback. But the negative feedback loop isn't just the outgoing signal. It also picks up back EMI from the speaker. A speaker is an electric motor, but it's also an electric generator hooked to a spring. Energy put into it is stored by and distorted by the suspension, then fed back into the output of the amplifier in a time and phase delayed manner. Yuck. And unless the output of the amplifier has infinite impedance (which it does not), then that back EMI is getting injected into the global negative feedback loop, doing things an 8 ohm resistor in the THD test doesn't do to the signal. The negative feedback loop is reducing input distortion, but increasing speaker EMI. At which point the "distorted" impedance-matched output transformer of an old school tube amp starts looking like a much better proposition...
jdietrich 7y ago
Two words: placebo effect. Above a certain (surprisingly inexpensive) point, most listeners just can't tell the difference or reliably pick a favourite between different gear in blind ABY tests.
- beat 7y ago
  I think that's a lazy argument. Context matters a great deal, and "blind AB tests" don't mean what you think they mean. I play guitar, and have recorded/produced numerous albums. When I'm playing, I can easily tell the difference between subtleties like which kind of guitar pick I'm using. But listening back to recordings of my own playing that I made, I sometimes couldn't even tell you which guitar I used. Now, I don't think you're suggesting that all guitars sound alike here. But as an example of the kind of context distortion of the AB test, that's what it suggests.
  - jdietrich 7y ago
    "Context" in this context is placebo. If one headphone amp genuinely sounds better than another, then it should reliably win in blind tests. If you need to see the nameplate on the amp to know that it sounds better, then it doesn't actually sound better in any meaningful way. If you can't tell your guitars apart blindfolded, that's nature's way of telling you that you own too many guitars.

by beat 7y ago

dsr_ 7y ago

The difference between the subjective and objective schools is this: objective school: if we perform a high-N properly double-blinded ABX listening experiment, we can be confident that humans can either reliably tell a difference between A and B or cannot reliably distinguish between A and B. Once we establish a reliable difference, we can have informed individual opinions on whether A or B is better. subjective school: all experiments are worthless because every listener and every listening situation is unique.

beat 7y ago
You're misrepresenting both schools here. First, the "objective" school consists largely of internet loudmouths who have never done an actual A/B test. They're saying what seems intuitive to them, and imagining it's logical. Second, most serious subjectivists recognize the value of experiments and testing. Where they disagree with the would-be objectivists is that when their subjective experience disagrees with the test, they suspect the test might be wrong as well as the possibility that their subjective experience might be wrong. The so-called objectivists argue that when the test disagrees with the subjective experience, then the subjective experience must be purely imaginary. This perspective could be easily disproven with a test...
- dsr_ 7y ago
  Somebody might be misrepresenting something here, yes. I especially like the way you managed to exactly explain the subjectivist viewpoint here while being completely fair to the objectivists.
  - beat 7y ago
    When it comes to sensory aesthetic experience, I don't think there's any such thing as a true objectivist. Acknowledging the limitations of scientific method for testing personal experience is itself a "subjective" thing, and any good scientist knows that when the results of one measurement disagree with another, it doesn't mean the other measurement is necessarily wrong. But I'm not talking about scientists or the scientific method here. I'm talking about dudes on the internet who claim they are "objective", which is a whole different horse.
    - dsr_ 7y ago
      You are continuing to make your point eloquently.
  - beat 7y ago
    Let's put it another way... subjectivist says that falling onto concrete hurts more than falling onto pillows. Objectivist says you're falling at the same speed either way, so the difference in pain must be your imagination.

sethhochberg 7y ago

Yes, mystery still remains in some parts of the audio world - in particular when we're talking about transducer theory, there are some aspects of loudspeaker and microphone performance that we can reliably characterize with derived equations, but where we still don't totally understand how those models translate back to the underlying physics fundamentals... but these are relatively specific edge cases in speaker design. Amplifiers and DACs have much less mystery about them - the math is solid, extremely well understood, and tested extensively in related fields like radar and sonar where the tolerances tighter and incentives for getting it right are stronger. Marketing absolutely drives specs (and especially specs without tolerances) when pushing gear, but that doesn't mean that the measurements are somehow invalid. Just expect the specs to tell you how close to the goal of a "wire with gain" you're getting, not to tell you specifically how the measured performance deviates from that goal. It also gets a lot more complicated when you're dealing with devices like headphones that have widely variable impedences - an amplifier that measures relatively flat into a medium-impedance load might fall apart when given dramatically higher or dramatically lower input impedance, and impedance matching is still a somewhat overlooked issue in the industry. The elephant in the room is always that some people just don't want to admit they think colored sound is better, so they convince themselves that there must be some aspect to audio performance that the science can't quantify - in reality, they're just avoiding quantifying a warm EQ curve, or nonlinear distortion, etc. I've studied audio electronics and DSP for audio at length, write plugins for audio software, have worked as a recording engineer, etc... and have no problem saying that mild nonlinear distortion and a bass boost sounds nice. The industry knows what "sounds good" and uses it to sell gear, but consumers think they want accuracy, so they get marketed to with terms like "transparency" or "resolution", and explain away unpleasant results with terms like "synergy" (or lack thereof).

beat 7y ago
Ok, since I brought up THD as a bad measurement, let's take a look at what, exactly, is being measured. A standard THD test measures harmonics generated from a sine wave at 1khz, into a resistive output load. So, how much does a 1khz sine wave represent an actual musical signal? And how much does a resistive load represent speaker impedance? The answers are "not at all", and "not at all". Do you see the problem yet? Of course you do. And that's the problem with amplifier specs. They're measuring what is easy to measure, not what reflects sonic behavior. And it gets worse, because it leads to designing for specs rather than designing for sonics. The easiest way to get "low distortion" spec-wise in an amp is large amounts of global negative feedback. But the negative feedback loop isn't just the outgoing signal. It also picks up back EMI from the speaker. A speaker is an electric motor, but it's also an electric generator hooked to a spring. Energy put into it is stored by and distorted by the suspension, then fed back into the output of the amplifier in a time and phase delayed manner. Yuck. And unless the output of the amplifier has infinite impedance (which it does not), then that back EMI is getting injected into the global negative feedback loop, doing things an 8 ohm resistor in the THD test doesn't do to the signal. The negative feedback loop is reducing input distortion, but increasing speaker EMI. At which point the "distorted" impedance-matched output transformer of an old school tube amp starts looking like a much better proposition...

jdietrich 7y ago

Two words: placebo effect. Above a certain (surprisingly inexpensive) point, most listeners just can't tell the difference or reliably pick a favourite between different gear in blind ABY tests.

beat 7y ago
I think that's a lazy argument. Context matters a great deal, and "blind AB tests" don't mean what you think they mean. I play guitar, and have recorded/produced numerous albums. When I'm playing, I can easily tell the difference between subtleties like which kind of guitar pick I'm using. But listening back to recordings of my own playing that I made, I sometimes couldn't even tell you which guitar I used. Now, I don't think you're suggesting that all guitars sound alike here. But as an example of the kind of context distortion of the AB test, that's what it suggests.
- jdietrich 7y ago
  "Context" in this context is placebo. If one headphone amp genuinely sounds better than another, then it should reliably win in blind tests. If you need to see the nameplate on the amp to know that it sounds better, then it doesn't actually sound better in any meaningful way. If you can't tell your guitars apart blindfolded, that's nature's way of telling you that you own too many guitars.