I don't know what you are talking about. I don't understand the concept....of a perfect recording or listening room.
Subjectivity is a major feature of the high end audio
landscape. As I said, the difficulty is entirely between the
ears, and if you read much of the literature of cognitive
psychology you have to conclude that it is hideously
complex and not well understood, not to mention varying
dramatically between individuals.
Sixty years ago or so, measurements corresponded better
with subjective opinion, but I think that was because the
equipment didn't measure very well. Now it generally
measures very well, and the objective technical problems
are largely solved.
To paraphrase McLuhan, we take our mature technologies
and turn them into art.
OK, I'll stop stirring the pot...
When typical audio amplifiers had outputs of a few watts, crossover networks were simple if they existed at all, and high fidelity sound systems had an FR of 100 hz to 10khz, measuring amplifiers the way we still do made sense. The FR looked like a roller coaster and THD was 5 to 10 percent at rated output. The measurements showed real differences that correlated to what we heard. But as amplifiers improved and demands on them became much greater measurement techniques didn't keep up. Measuring the FR of an amplifier at 1 watt into an 8 ohm resistor won't tell you what that amplifier will do at 50 watts powering an AR3 where impedance drops below one ohm at some frequencies. Had FR been measured at several power levels up to rated power into a partly inductive load then it would have been obvious that some amplifiers simply could not supply power at high frequencies in bursts. This is similar to the concept of gain power bandwidth product. The concept of TIM would have been superfulous because it would have been understood as an FR limitation as a function of power output.
The inability or unwillingness to define how the ideal amplifier should perform electrically and then devise measurements that compare real world performance of actual amplifiers lies at the heart of what is a very lucrative controversy. What makes it even more confusing and obfuscates the real issues for the tyro even more is to bring into the discussion factors which have nothing to do with electrical performance. Sound is not an electrical phenomenon, it is a fluid dynamic phenomenon. Audio power amplifiers don't amplify sound, they don't even amplify electrical power. They amplify voltage and their final stage has enough current available to drive a loudspeaker. That is the only rational way to judge them. Objective/subjective are just more ways to confuse the real issue and create a market for an endless stream of variants on the same theme. BTW, that was one of Cheever's shortcomings. He never defined an absolute minimum of distortion below which it didn't matter what the components are because they are inaudible when they are converted to sound by a loudspeaker. The "there's always room for improvement" argument is not rational but it can be profitable if customers believe it.
Just read an interesting test of three DACs in a Dutch on-line HiFi journal.
I'll translate roughly; in order of preference of the 'blind panel':
- This one is the best: Musicality, spaceousness, depth of reproduction.
- This one came second: Large voice projection, deep lows, rougher dynamics (whatever that it).
- This one came last: fine-grained, neutral, analytic, audiophile reproduction.
So, technically speaking the last one is the better one as it adds least and takes least away from the sound. But it is clear that preference was given to some measure of coloration or sound manipulation.
Now you can't argue with preference of course. But it does illustrate the dire straits of an audio designer: do you go for neutrality, what goes in is what comes out, or do you go for 'the unforgettable experience' and the hell with accurate reproduction (I charge it slightly, but you get the point).
So, all you engineers who design amps that are all but a wire with gain: you'll never make it in the marketplace, because wires with gain are boring and nobody wants a boring amp. Also, the marketing dept can't do anything with neutrality. They need to sell the 'unforgettable experience'.
I think Nelson summed it up accurately.
jan didden
I'll translate roughly; in order of preference of the 'blind panel':
- This one is the best: Musicality, spaceousness, depth of reproduction.
- This one came second: Large voice projection, deep lows, rougher dynamics (whatever that it).
- This one came last: fine-grained, neutral, analytic, audiophile reproduction.
So, technically speaking the last one is the better one as it adds least and takes least away from the sound. But it is clear that preference was given to some measure of coloration or sound manipulation.
Now you can't argue with preference of course. But it does illustrate the dire straits of an audio designer: do you go for neutrality, what goes in is what comes out, or do you go for 'the unforgettable experience' and the hell with accurate reproduction (I charge it slightly, but you get the point).
So, all you engineers who design amps that are all but a wire with gain: you'll never make it in the marketplace, because wires with gain are boring and nobody wants a boring amp. Also, the marketing dept can't do anything with neutrality. They need to sell the 'unforgettable experience'.
I think Nelson summed it up accurately.
jan didden
Technically speaking - wouldn't it be nice to compare measurements of tested DACs with sound impressions? Maybe the "neutral" one measures worse then the rest?
Technically speaking - wouldn't it be nice to compare measurements of tested DACs with sound impressions? Maybe the "neutral" one measures worse then the rest?
Yes, could be, but that's irrelevant here, isn't it?
The point is that they rated the one that they thought was most neutral, last.
jan
I copied and pasted that from Cheever's paper.
So I presume that this is just one more of Cheever's errors.
Sure be we know that distortion makes for a LESS boring sound. All kinds of extra harmonics, intermods etc. That really 'spices up' your sound, makes it 'emotionally involving'. SE tubes being a point in case.
jan didden
Or, ask the man himself:
http://www.linearaudio.nl/interviews/np.pdf
So he doesn't mention working with Bob, but he did say there are he few he doesn't want to metion.
So, it's all hidden in the cloak of time...
jan didden
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I think that exactly because they are not "technical" people they use the words less literally. So "neutral" doesn't have to mean neutral - it could also mean "sterile", "lifeless" etc. If we can't compare measurements of reviewed DACs we can't say anything about reviewers listening preferences vs. technical performance. Actually you are criticizing their use of words.
I doubt that Nelson Pass had very much, if anything to do with Carver's designs, at least from the beginning. Bob Carver worked with Geoff Cook and Bascom King in those early days. Geoff was the guy who got him 'on the map' so to speak. As consultants, both Nelson and I have worked for many companies. They usually take what they can and go elsewhere, so one tends to work for a whole stream of them, over the decades.
Since Nelson Pass is here on this website, AND even sometimes contributes to this thread, why not ask HIM?
Since Nelson Pass is here on this website, AND even sometimes contributes to this thread, why not ask HIM?
I would like to comment on something that bothers me on this thread. That is general 'badmouthing' or 'criticism of someone else's research, without the researcher being placed in a position to respond. In this case today, it is 'Cheever's Thesis', over the years, it has been: Otala, Bybee and Hawksford, to name 3 other examples.
This is very 'sophomoric' to attack someone behind their back, especially without stating specifics. I hope that it does not continue here, if at all possible.
This is very 'sophomoric' to attack someone behind their back, especially without stating specifics. I hope that it does not continue here, if at all possible.
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