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the way I analyze audio performance

post #1 of 16
Thread Starter 

I have a way of looking at things ..  my sixth sense guides me to building and modifying a system that is as accurate as I can get it. There are engineers who disagree, and that's fine. For the most part I think their work does a poor job of reproducing a musical performance, but I'm sure from their own perspective they think it does a good job.

 

To each his own.

 

Here is my thing

 

  • My Premise #1: music creates experiences and feelings in listeners. If these are pleasant feelings, the listener wants to come back for more.
  • My Premise #2: a recording is an attempt to spread musical experiences and feelings to more people at later dates and times
  • (Note. Premise #2 does not require that all people experience music the same way or that the reproduction feels exactly the same as the original. Premise 2 basically rules out classes of other possibilities, like "recording exists to help people enjoy watching an oscilloscope", "recording exists to frighten people", "recording exists in order to push some distortion numbers toward zero". None of that is why recording exists. )
  • My Premise #3: there is always distortion in the playback chain. From microphone to speaker, every device along the way adds at least a small bit of distortion. What's more, the playback is not creating the true wavefront heard at the microphone position, so the imaging in your 2-channel home setup is always going to be "faked" to an extent.

 

Okay, so we have distortion. Here are some examples.

  • The violins are too bright.
  • The violas are muffled.
  • The bass is flabby.

 

These are descriptions of a human perception. But these happen to correlate fairly directly to simple objective measurements.

 

the violins are bright: might be caused by a tilted-up frequency response

the violas are muffled: maybe a dip in the f.r. around 3-4 KHz?

the bass is flabby: poor damping factor in the amplifier

 

Okay, that's great, but these are relatively simple "trees"-- but what of the forest, the Gestalt? Here's one possible gestalt factor:

 

British reviewers use the term Pace, Rhythm and Timing (PRAT). They observed that most music has a rhythmic quality to it -- it's not simply the beats repeating over and over.

 

The beats could

  • Feel very insistent, demanding. Or be sneaky.
  • Create a driving forward feel, or a laying back feel.
  • Come at minutely different times and thereby make powerful musical/emotional expression. (the Time dimension of music conveys much intense feeling)

 

Furthermore, the quality could change throughout a piece. How well-differentiated are the different sections? Do they sound clearly different?

 

The PRAT accuracy of a system can't be reduced to one cause/effect. It emerges from many features.

 

The interesting thing is that when a playback system gets the PRAT wrong (relative to the original performance), it changes the perceived performance. It's not like a muffled viola, in which the listener can tell it's a muffled viola and still do their best to pay attention to the player's performance. But when a system changes PRAT it is changing the performance. A person may not be able to tell--- does the bass guitar sound lazy and late because the player was bad, or because the system messed up his playing?

 

So in my book it is critical to look at distortions first and foremost as distortions in performance, and only secondly as some individual "trees" (specific measurements).

post #2 of 16

You're on the right track, and I can clarify a bit.

 

> the violins are bright: might be caused by a tilted-up frequency response

> the violas are muffled: maybe a dip in the f.r. around 3-4 KHz?

> the bass is flabby: poor damping factor in the amplifier

 

You are absolutely correct to ascribe most "tonality" differences to simple frequency response. But for that last one, damping factor is not nearly as relevant as room and speaker resonances. Especially with modern solid state amplifiers. Rooms with no bass traps have multiple resonances that can extend for half a second or more. So when a bass note sounds at one of those frequencies, the result is "flabby" bass.

 

> British reviewers use the term Pace, Rhythm and Timing (PRAT). They observed that most music has a rhythmic quality to it -- it's not simply the beats repeating over and over.

 

American audiophiles also refer to PRaT, but it's total nonsense. These are established musical terms that have nothing to do with whatever audiophiles might believe.

 

--Ethan

post #3 of 16
Thread Starter 
Quote:
Originally Posted by EthanWiner View Post

> British reviewers use the term Pace, Rhythm and Timing (PRAT). They observed that most music has a rhythmic quality to it -- it's not simply the beats repeating over and over.

 

American audiophiles also refer to PRaT, but it's total nonsense. These are established musical terms that have nothing to do with whatever audiophiles might believe.

 

--Ethan

Hi Ethan,

Thanks for the reply. As far as "established music terms" -- well, that's kind of my point though -- that the performance of an audio system can be described in musical terms. If we are talking about attending a live performance of an orchestra, I think some conductors have lively and varied rhythmic quality, and some are dull. I think a recording/playback system can make PRaT that was lively in the performance turn into something dull. Or at the other extreme, it can overemphasize it. Experimenting with different tubes in my Woo WA6-SE headphone amplifier, I notice that the 6CY7 overemphasizes PRaT a bit, while the 6FD7 "dullifies" it. My point is that I analyze this performance using the same perceptual faculties that I use to analyze conductors in live performance.

 

When Trevor Pinnock plays Bach on the harpsichord, the rhythmic feel is completely different than when Gustav Leonhardt plays. Again, these are due to differences in the original performance, but an audio system can make the same kinds of effects.

 

Another musical quality that I talk about -- I don't think this has a universal meaning -- is "emotion" vs. "dry." Some audio systems are really dry -- like no emotion comes through. I also think certain conductors I've heard at Walt Disney Concert Hall are pretty dry, while others communicate emotion.

 

I've noticed that some people really disagree with this way of thinking. I think everyone finds their way to something that gives good results, from their perspective. I am fortunate to have found equipment that was designed (and in my case, extensively modified) by designers who think the same way I do. There is some equipment I can't stand -- Krell comes to mind -- but I'm sure for some people it's just the thing.

 

Mike

post #4 of 16

I don't see how audio gear can change the basic tempo of music unless it involves a time-stretching algorithm, which of course playback systems don't (usually) include. The only thing a playback system can do is alter the frequency response, and add distortion and / or noise. Now, a room can add a liveness in the form of reverb / ambience / echoes. But that's outside of the gear. You may find this article useful:

 

Audiophoolery

 

It explains all of the parameter categories that define fidelity. You'll see that PRaT are not in there. Follow-up questions here are welcome.

 

--Ethan

post #5 of 16
Thread Starter 

Equipment doesn't change the tempo, but it can change the sense of whether the tempo works -- musicians never set the tempo in isolation of other factors like their articulation and the room reverberation. Change the quality of the articulation and the tempo no longer makes musical sense. Maybe it seems to drag, maybe it seems to rush.

 

Yes, I read that article when it first came out in Skeptic Magazine.

 

For me, the idea of reducing distortion to a few categories isn't the right way to understand what equipment is faithful to the original music.

 

Let me give an example. Let's say that instead of talking about reproduction of sound, let's talk about reproduction of a visual scene by taking a photograph. Let's say that we have a camera which can take images which are close to the original, but does introduce two forms of distortion: it distorts shapes a little and it changes colors a little. Let's suppose the situation is such that we can mathematically reduce the errors in any reproduced image to these two categories: changing shapes and changing colors.

 

Now let's suppose we are reproducing the Mona Lisa.

 

You might look at the reproduction and note some changes in shapes and colors. I might look at the reproduction and think-- "She looks sad."

 

To me, the most important quality to reproduce is that mysterious smile. So the most important observation is that she looks sad. Your method of reducing the distortions to a few categories doesn't capture many of the important observations. That's why it's not helpful, at least the way I go about things. It might be that for your ear/brain (the way your brain makes a subjective impression out of sound) these categories are well-correlated to perception, and perhaps that is why this analysis is helpful for you.

 

Mike

post #6 of 16

LOL!!!

 

Ethan, you're in way over your head here.  All those years of study and practice and work that you've spent your life on are as nothing when compared to the pure awesomeness of a truly incoherent audiophile belief system. 
 

post #7 of 16
Thread Starter 
Quote:
Originally Posted by BlindInOneEar View Post

LOL!!!

 

Ethan, you're in way over your head here.  All those years of study and practice and work that you've spent your life on are as nothing when compared to the pure awesomeness of a truly incoherent audiophile belief system. 
 

Wow-- did I condescend to you? What about this makes you so angry and partisan?

post #8 of 16

Hi Mike1127!

 

Pleased to meet you!

 

No, I'm not mad at you.  You gave me a very good laugh, why would that make me angry? 

 

I will say that, in my opinion, meaningless though that may be, when it comes to audio science and engineering, not only do you not know what is going on, you don't even suspect.  Your arguments, far from being cogent, don't even rise to the level of being intelligible.  I've read several of your posts and I have no idea what you are talking about.  Accordingly, the example above of you attempting to instruct Ethan Winer on how audio works struck me as being sublimely absurd.

 

I know that you will see this as a direct attack on you and not want to listen to what I've got to say.  I'll admit up front that I'm not the most personable individual in an online forum. 

 

Perhaps all is not lost though.  You yourself could, by a moderate application of effort, study audio science and engineering.  Doing so will make you more aware of the issues involved and the reasoning that has been followed to arrive at the conclusions held at large in audio today.  In the alternative, you could also realize that while you yourself decline to make that effort, other people, let us call them "authorities," have made that effort and do understand what goes on in audio science and engineering.  Ethan Winer is one of those authorities. 

 

It would behoove you, before you attempt to school Mr. Winer on how audio works, to spend a little time yourself learning about audio so you can couch your arguments in terms generally accepted by audio engineers at large.  If you want to introduce a new way of thinking about audio, it's incumbent on you to do so in terms that your audience can understand and identify with. 

 

All the best!

 

BlindInOneEar  

post #9 of 16
Thread Starter 
Quote:
Originally Posted by BlindInOneEar View Post
 
No, I'm not mad at you.  I know that you will see this as a direct attack on you..
 

Pardon me, but when you have nothing to say but to mock someone, then you are attacking them and it gives the impression you are threatened, and probably angry as well.

 

My post immediately above your first reply is simple enough. If you really want to have a discussion, why don't you start with that.

post #10 of 16

Mike, I won't beat you up as badly as BlindInOneEar, but he's correct that you really don't understand how audio equipment works. Not to shill my book The Audio Expert, but it's exactly what you need. Further, all I address is how to define raw fidelity. I never discuss how music makes you feel (happy, sad, whatever) because those are unrelated to fidelity. That said, I assure you there's nothing in an audio amplifier that can make the perceived tempo of music "work" or not. If you have access to some basic test gear and maybe some audio plug-ins, you could do some tests that will convince you.

 

--Ethan

post #11 of 16

mike,

you're in the wrong forum.  as a former Naim Audio owner, from source to speakers, i understand what you're talking about.  the Naim presented the sense of rhythm and musical phrasing much different than my BM DAC1/Krell/ATC monitors.  i perceived the Naim as having a slight boost in the mid-bass, a forward/peaky mid-range, and well attenuated freq above 16KHz to kill any sense of "air".   

post #12 of 16

Hi mike1127! 

 

Sure we can discuss some of the things you said!  Sorry, I'm new to posting in this forum so I'm pretty clueless about how to use the quoting system.  Please bear with me.

 

You said: "I have a way of looking at things ..  my sixth sense guides me to building and modifying a system that is as accurate as I can get it."

 

I say: I have to admit that when it comes to subjectivism you take the cake.  I've heard of many subjectivists who dismiss objective testing out of hand and insist on making all their audio related decisions and purchases based solely on listening tests.  Apparently you go these folks one step better and don't even bother with listening tests to make your audio related decisions.  Instead you rely on your "sixth sense," whatever that might be, to guide you.  Call me old-fashioned, but I recommend at least listening to stuff before actually spending any money on it.

 

You said: "There are engineers who disagree,"  

 

I say:  I'll bet there are!  In fact I bet every engineer out there would disagree with using a "sixth sense" as a guide to building and modifying a system.  At least the honest ones.   

 

You said:  "For the most part I think their work does a poor job of reproducing a musical performance,"

 

I say:  Those poor engineers.  They sweated all those years in school learning engineering and all those years thereafter learning the ropes while working on prototypes, busting their butts so they can get their pride and joy out the door and into their customers' hands.  And they still don't know what they are doing.  We know this because mike1127 says so.  But can you blame the engineers?   After all they don't have a sixth sense, only degrees in engineering and experience in designing components and what good is a BSEE and hands on experience to anyone in the audio business? 

 

You said:  "but I'm sure from their own perspective they think it does a good job."

 

I say:  All the engineers can do is use the knowledge they acquired getting their degrees, exhaustively measure their prototypes and conduct extended listening tests first in house and then by getting feedback from their customers.  I'm sure after all the work they've put in they've pretty thoroughly deluded themselves into thinking their product offers value for their customers.   Since customers are buying the stuff apparently the customers think it sounds good too.  Poor saps.  If only they had a sixth sense then maybe they could see the light! 

 

Enough.  You get the idea.  You stroll into the Sound Science forum and start a thread basically dismissing the efforts of EEs at large and the body of science built up to date and instead start espousing some nonsensical points about how PRaT is more important than any of the scientifically accepted measures of audio accuracy.  An honest to God audio engineer deigns to reply to your post in an attempt to enlighten you and you blow him off and try to tell him he's wrong.   I stumble across the scene of someone who obviously doesn't know what he's talking about trying to educate someone who obviously does know what he's talking about and have a good laugh.  You get defensive, I won't back down.  I guess that about brings us up to date.  I'm afraid that we're going to have to agree that I disagree with your present view of the world of audio. 

 

Please note, I am not saying you're stupid!  Far from it.  I am saying you're ignorant, and ignorance can be fixed.  Ignorance is nothing to be ashamed of.  All of us, every single person on this planet, has been ignorant at one time or another.  I couldn't begin to list the topics in which I'm woefully ignorant at this very moment.  In every case it can be cured with some time and effort.  Why not take Mr. Winer up on his offer and buy and read his book?  It could well be a turning point in your audio career.  Dollar for dollar it may turn out to be the best "tweak" you've ever invested in. 

post #13 of 16
Quote:
Originally Posted by EthanWiner View Post

Mike, I won't beat you up as badly as BlindInOneEar, but he's correct that you really don't understand how audio equipment works. Not to shill my book The Audio Expert, but it's exactly what you need. Further, all I address is how to define raw fidelity. I never discuss how music makes you feel (happy, sad, whatever) because those are unrelated to fidelity. That said, I assure you there's nothing in an audio amplifier that can make the perceived tempo of music "work" or not. If you have access to some basic test gear and maybe some audio plug-ins, you could do some tests that will convince you.

--Ethan

Hi Ethan, bought your book and I really enjoyed it (what I understood, being an audio neophyte), and I have a question. Is tube rolling wholly placebo/bias? I understand that it's the harmonic distortion that I enjoy with tubes, and I can live with that. They do add a "sweetness" that appeals to me a great deal of the time. However, I would swear that I hear differences between different tube sets with my Cary amp. It isn't blatantly obvious, but there are (it seems to me) consistent differences with certain combinations. Is that likely or even possible?
post #14 of 16

Tubes can sound (and measure) differently. So I don't doubt that different tubes could change the sound. But the only way to know for sure is to measure the frequency response and distortion at a fixed (same) volume level before and after changing tubes. Measurements are much more reliable and repeatable than listening alone.

 

--Ethan

post #15 of 16
Fair enough. I've been meaning to setup a test bed and will look into it at some point in the intermediate future. One thing from my imperfect testing that's stood out is that tube price seems to have nothing to do with performance. My favorite KT88s are newer JJ Teslas, which comparatively are rather inexpensive. I suppose I won't know for sure until I remove the possibility of bias, though.

Thanks smily_headphones1.gif
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