Measurements and the Correlation of What We Hear

[garylkoh]

Otherwise we will have a debate that will reiterate endlessly, but I am happy to join in repeatedly like others as it passes the time

Thanks
Orb

Orb,
I envy you your time to debate this topic. It is of extreme interest to me, but I don't even have the time to read and re-read all the posts, let alone have the time to post.

 

[Orb]

Orb,
I envy you your time to debate this topic. It is of extreme interest to me, but I don't even have the time to read and re-read all the posts, let alone have the time to post.

Why envy, wouldn't you say it is a curse to go through all the posts, only for a similar thread to appear a week or a few days later, again and again
Oh woe is me... you got me to respond
Cheers
Orb

 

[Gregadd]

Why envy, wouldn't you say it is a curse to go through all the posts, only for a similar thread to appear a week or a few days later, again and again
Oh woe is me... you got me to respond
Cheers
Orb

You're reading my mind.

 

[fas42]

Just to add to everyone's misery, I'll throw in another dollop. Of course, if all are perfectly content with what they have, and believe absolutely nothing can be done to improve their experiences apart from throwing ever bigger lumps of money at more esoteric and fancier looking gear then we should just give away all such discussions ...

I feel the discussion needs to appreciate that we have the engineering measurements that provide excellent information on the performance-behaviour-trait-characteristics of an audio product (including speakers), and then we have the scientific physics-psychoacoustics of waveforms/sounds and measurements relating to how we perceive sounds-music-rythm.

That I would vehemently reject: we have way not enough information about how components behave.

While the 2nd is more focused on complex waves found in nature and from musical instruments/voice, where it is critical to look at the sound in both frequency and time domain (envelope of the sound) and the fundamental/partials-harmonics (that help to define tone and timbre,etc).

To correlate what we hear we need to consider the scientific approach and this means we can only truly look to match an audio products performance to what we hear by using a musical complex wave that is ideally a major chord; this can be a recorded real instrument or derived by waveform synthesis.

However as I mentioned in the past the scientific complex waveform approach is meaningless from an engineering perspective as it would be impossible to relate this to an electrical components performance-behaviour-traits, hence why sinewave tones-squarewaves-etc are critical.

This means we cannot solely use existing engineering related measurements in such debates where we want to put forward the case of correlating an audio products performance measurements to actual specifics such as timbre-sibilance-etc and affect on an instruments reproduced sound.

Sorry, this is totally wrong. It is easy to generate a test signal which is as complex as we like, mimicking a instrument sound if we like and then it just a case of using intelligent software to pull apart the resultant output of the electronics, to see exactly what it did right and what it did wrong. Trouble is, no-one's doing it, probably because they can't be bothered and no-one else is paying them to do it ...

Frank

 

[MylesBAstor]

Just to add to everyone's misery, I'll throw in another dollop. Of course, if all are perfectly content with what they have, and believe absolutely nothing can be done to improve their experiences apart from throwing ever bigger lumps of money at more esoteric and fancier looking gear then we should just give away all such discussions ...


That I would vehemently reject: we have way not enough information about how components behave.


Sorry, this is totally wrong. It is easy to generate a test signal which is as complex as we like, mimicking a instrument sound if we like and then it just a case of using intelligent software to pull apart the resultant output of the electronics, to see exactly what it did right and what it did wrong. Trouble is, no-one's doing it, probably because they can't be bothered and no-one else is paying them to do it ...

Frank

To follow up on your comments, if we have all the measurements we need, how come at best the sound is a poor approximation of the real event?

 

[Gregadd]

To follow up on your comments, if we have all the measurements we need, how come at best the sound is a poor approximation of the real event?

Myles see my statement about the fault lying within us not the equipment. Smile

 

[mep]

Most of the people seemed to have lost sight of the intent of this thread, and that was to talk about how measurements correlate to the sound we hear. A few people “got it” such as Amir and Orb among others, but this thread quickly deteriorated into dogmas and mantras with my least favorite being “if you can hear it, it can be measured.” The people that utter those words don’t stop and think about how rare actual measurements are of high-end gear nor the fact the measurements with the exception of digital products are pretty basic and haven’t changed much in 50 years or so.

What was missed in all the noise by most was that not only are measurements not provided by any of the high-end manufacturers I’m aware of, no one has yet to devise measurements that have been widely adopted that would correlate with so many aspects of sound reproduction outside of the basics such as FR, power output into various loads, SNR, channel separation, ability to reproduce a 1 Khz and 10 kHz square wave, and distortion.

My challenge is if we have two components that have equally outstanding basic measurements (assuming you can even find measurements for two pieces of gear you are trying to decide between) and yet they don’t sound alike, what measurements can we look at that we don’t currently have that would give us some correlation to the different sound qualities? And by all means if you think we already have them, do tell what they are.

 

[mep]

To follow up on your comments, if we have all the measurements we need, how come at best the sound is a poor approximation of the real event?

Ding, ding, ding. We have a winner.

 

[fas42]

To follow up on your comments, if we have all the measurements we need, how come at best the sound is a poor approximation of the real event?

I'm confused, Myles, I just said we DON'T have enough measurements, echoing what Mark stated ... -- scratch the former, I misunderstood your point, sorry.

As regards more comprehensive measurements, Ben Duncan was talking of such 25 years ago, and he appears to have been totally ignored. And the fact that he is regarded by some as an authority on subtleties of circuit behaviour seems not to have served him any benefit in progressing people's thinking.

Part of the problem is that we have some nice, expensive gear that purports to tell all, so that has become THE authority on informing us on what's going on.

Frank

 

[RogerD]

Most of the people seemed to have lost sight of the intent of this thread, and that was to talk about how measurements correlate to the sound we hear. A few people “got it” such as Amir and Orb among others, but this thread quickly deteriorated into dogmas and mantras with my least favorite being “if you can hear it, it can be measured.” The people that utter those words don’t stop and think about how rare actual measurements are of high-end gear nor the fact the measurements with the exception of digital products are pretty basic and haven’t changed much in 50 years or so.

What was missed in all the noise by most was that not only are measurements not provided by any of the high-end manufacturers I’m aware of, no one has yet to devise measurements that have been widely adopted that would correlate with so many aspects of sound reproduction outside of the basics such as FR, power output into various loads, SNR, channel separation, ability to reproduce a 1 Khz and 10 kHz square wave, and distortion.
My challenge is if we have two components that have equally outstanding basic measurements (assuming you can even find measurements for two pieces of gear you are trying to decide between) and yet they don’t sound alike, what measurements can we look at that we don’t currently have that would give us some correlation to the different sound qualities? And by all means if you think we already have them, do tell what they are.

Mark,

There are so many variables,resistors,capacitors,transformers,circuit design,grounding scheme,tube compliment ,ect,ect ,why would measurements mean anything when spending 10K on a amplifier or preamp? It either passes the ear test or it doesn't.

I can take a brand new Monarchy NM24 tube dac roll the tubes and change the two coupling caps from wima to mundorf supreme and transform the sound and the manufacturer posts this info on his website!

In this day and age quality design and quality parts tells the true story and measurements only provide reinforcement to the designer and the buyer.

I think speakers are another ball game. In the twenty first century there isn't any high end manufacturer that is worth a damn who doesn't voice his equipment or use computer modeling for circuit design. I just don't get what we argue about, measurements on today's electronics,c'mon.

 

[mep]

Roger-I get everything you say-trust me. Many of us rely on our ears to tell us if what we are hearing sounds real, me included. In reality, those that proclaim the sacredness of measurements still have to do the same because OEMs don't provide measurements, they only provide unverified specifications. I do think some people confuse specifications for measurements. I also think that JA from Stereophile does as good a job as anyone in the industry of measuring gear. If you read his reviews of the gear he measures, you can see how common it is that the OEM's specifications don't always match his measurements, and sometimes by a lot. And another thing that John tries to do is correlate the measurements to what he thinks will be heard. The flip side of that is that John is often puzzeled at comments some of his reviewers make in light of the measurements he makes.

 

[fas42]

In this day and age quality design and quality parts tells the true story and measurements only provide reinforcement to the designer and the buyer.

I think speakers are another ball game. In the twenty first century there isn't any high end manufacturer that is worth a damn who doesn't voice his equipment or use computer modeling for circuit design. I just don't get what we argue about, measurements on today's electronics,c'mon.

Roger, I have to say that Mark is making an excellent attempt on focusing people's attention on a key requirement for moving forward, we DO need to be able to measure, yielding a set of figures which clearly indicate what's going on. The fact that it may be hard to do, that the measurement technique may be controversial or expensive is besides the point, we just need to know what has altered when changing a cap makes a difference, from the point of view of the output of the system.

Frank

 

[MylesBAstor]

So, there is one reason if you pick on just one measurement, and not look at all in total, you can have two amps not sound the same...simply because the measuring was not in depth, NOT that there is something we can not measure in a voltage or current audio wiggle.

A person who knows electronics does not pronounce that the THD measurement is the only measurement, or the simple twin tone IMD measurement is the only measurment, but then again, its the audio industry that refuses to go further.


Tom

I think you should go back and reread your posts then because that is exactly what you've been saying in regards to THD being the beginning, middle and end all to the sound of equipment.

And your sorely mistaken if you believe the people like KOJ -- not to mention other top designers -- haven't gone light years beyond the "typical" measurements quoted. Go as I said previously to the LAMM website and look at all the measurements that Vladamir has posted for his equipment.

 

[Gregadd]

That aint what I wanted to say.

First, one must be perfectly clear on this: there is nothing about an audio amplifier that is not known by a person who has spent a better part of their lifetime designing REAL circuits (for example, Nelson Pass). There is nothing that he can not measure as far as an audio amp.

Second, the electronics that is not at the begining or end, that is to say, not the microphone or the speaker, are in no way mysterious for audio.

Inductance, capacitance, reactance, resistance are all well known and basic. There are no "mysterious" other things that affect audio, as far as replication of a voltage or current BETWEEN the microhphone and the speaker are concerned. The outliers are the microphone and speaker, the "motors", they are not consistant and we measure their EFFECT more than them directly, once the wiggle is CONVERTED into a voltage or current as in the microphone or once the speaker moves the air and we measure the air change with..hold on..a microphone!

We REPLICATE the voltage or current, and we can damn well tell if we replicated it exactly and far better than anybodys ears can, and again I am not talking the "motors"

I gave I thought was a good example, of how two different amplifiers, both measuring the same THD, could actually each be changing the phase shift (the timing) of the sinewave and the THD meter does not LOOK for that, but you could defintiely hear that, and I gave an example of the "phat" sound that can result.

So, there is one reason if you pick on just one measurement, and not look at all in total, you can have two amps not sound the same...simply because the measuring was not in depth, NOT that there is something we can not measure in a voltage or current audio wiggle.

A person who knows electronics does not pronounce that the THD measurement is the only measurement, or the simple twin tone IMD measurement is the only measurment, but then again, its the audio industry that refuses to go further.

I also tried to say that (excluding the microphone and the speaker) the recording is where all your ambience and air and fairly dust and soundstage and holographic presence and all that cool stuff comes from. Many of us have that recording where there is a dog barking like 50 feet directly to the right of our speaker, that is done in the recording. IF your electroincs "brings out" these things don't you always say it brought it out of the recording?

I also said that a null test, tests for all DIFFERENCES between an input and an output, as far as electroincs is concerned, and that test alone, can be used as a general indicator of how different the output is from the input without doing serious extraction of all the individual changes induced by a non perfect transfer function of an amp. I use that test along with an input signal that stresses the capabilities of the amplfier under test and I can tell you that a SET amp makes a lot of difference between input and output man. But people, including me, like that sound as well.

I have also quoted elsewhere that that soundstage you hear between the speakers is all created in your brain (there is no center channel, no?), and how the hell is that going to be measured in our lifetimes?

But voltage and current, no problem, except the audio industry will not go there for you, least one finds out that their $15K pre-amp is not nearly as good a REPLICATOR as my old Hafler unit! Then how would they feel, well, and the audio industry knows this, and that the audiphile would proclaim that we could not measure eveything there is and by golly my ears tell me that my amp sounds so much better....even though it is not as good a REPLICATOR.

No, not all replicators sound the same. I have never said that, but I will say, if you make the right measurments, one can proclaim that amp A is a better REPLICATOR than amp B as far as voltage and current are concerned.

Also, in the past, I have said that plain old stereo (POS), OK, piece of ****, is a poor poor REPLICATOR of a live event, and the first and easiest reason is that nowhere, at unamplified live musical events, do you have two round things or flat panels facing you and spewing sound waves at you. It all goes down hill from there. That is why folks like what is ADDED by some REPLICATORS and mikes and speakers and processors and blah blah, because we got such short thrift to start with as far as creating an "illusion"

Tom

I wrote a point by point rebuttal of this post then deleted it.


It's kind of strange that these guys know all there is to know about amps. Nelson Pass keeps introducing better and more expensive amps. If he knows everything he must be playing it close to the vest.

 

[RogerD]

I wrote a point by point rebuttal of this post then deleted it.


It's kind of strange that these guys know all there is to know about amps. Nelson Pass keeps introducing better and more expensive amps. If he knows everything he must be playing it close to the vest.

Funny how that is, but in his or any designers defense I must admit the quality of the parts manufactured and that make up equipment in the high end market has improved greatly. technology has it's benefits, I know this first hand because I have a pair of Ampex 350's that I had rebuilt for me and I spec'd all the parts and they are playing right now. Damn, 55 year old electronics can not sound this good,it's impossible,but good design with quality parts and your jaw might just be on the floor.

No I did not measure these parts or the 350's at the beginning or the end, my tech said the sine wave was about as perfect as it gets. Was I lucky? No I just did a lot of experimenting and listening, hard work but fun. I bet Nelson Pass voices every component that goes in to every one of his designs and yes they all build to a price point.

p.s. About the only measurement I look at anymore is the A weighted S/N ratio figure. The Lamm 2.1 preamplier measures -94db,not bad,but if it was -100 I would be impressed.

 

[Orb]

Just to add to everyone's misery, I'll throw in another dollop. Of course, if all are perfectly content with what they have, and believe absolutely nothing can be done to improve their experiences apart from throwing ever bigger lumps of money at more esoteric and fancier looking gear then we should just give away all such discussions ...


That I would vehemently reject: we have way not enough information about how components behave.


Sorry, this is totally wrong. It is easy to generate a test signal which is as complex as we like, mimicking a instrument sound if we like and then it just a case of using intelligent software to pull apart the resultant output of the electronics, to see exactly what it did right and what it did wrong. Trouble is, no-one's doing it, probably because they can't be bothered and no-one else is paying them to do it ...

Frank

We will have to disagree Frank, but I am just going by how the two are differentiated from the research and papers I have read; whether it relates to engineering and measuring (I have chatted to a few who write the software-tools in this field on this subject) or scientific research on sounds-music-rythm and our perception (again been lucky to chat to a few on this as well).

BTW I did state we can derive a complex waveform of an instrument from waveform synthesis, but the point is you will not be able to relate this in terms of engineering and how an electrical product behaves-performs.
Some scientific labs use waveform synthesis for greater control rather than real musical instruments (although being pedantic a synthesiser could be argued it is a real instrument as well, but hopefully readers understand my distinction).
If you could, then all the measurements and measuring tools would be using something like an instruments major chord, it is not about not bothering to do it, Paul Miller would be using this in an instant if it had actual use to engineers developing and building audio gear (he adds testing procedures-measurement capturing-analysis to the Suite tool pretty quickly).
I am sure same would be done with Audio Precision as these are all in competition and if a testing tool gives them the edge they will use it.

However the reality is as I said; sinewave tones, squarewaves,etc. as this enables an engineer to better understand what is happening in terms of performance-behaviour.
And this is the reason they are not doing it, if it was easy and was usable for testing audio products, then it makes logical sense to add the functionality.
Thanks
Orb

 

[Old Listener]

Well the only relationship between real science and what is discussed here is purely coincidental.

Speak for your own posts.

Bill

 

[JackD201]

In my opinion this thread has become nothing more than an intellectual pissing contest. The bottom line is that whatever measurements you take from input to output does not mean squat because you will only ever HEAR it if it is in a SYSTEM. Perfect null test? Whoopie do. Give me a colored hodge podge that in the end whose measurements hews closely to the original waveform in actual use to one that all measures supposedly flat individually but falls on it's face when measured from the listening position. In practical terms it's nothing but a security blanket or a crutch. They will only ever be guides for use and/or guides for quality control, etc. They will never be predictive because WE ordinary folks will never be able to look at those measurements and imagine what a piece of gear will sound like given every piece of music because we don't even know a single darned performance by heart. If one is self delusional enough to believe he knows at least one performance down to the tiniest level of audibility, whatever piece that might be, the sound of that will always be grounded on the impressions we had of that piece and NOT the actual sound. It's ludicrous.

 

[Gregadd]

Funny how that is, but in his or any designers defense I must admit the quality of the parts manufactured and that make up equipment in the high end market has improved greatly. technology has it's benefits, I know this first hand because I have a pair of Ampex 350's that I had rebuilt for me and I spec'd all the parts and they are playing right now. Damn, 55 year old electronics can not sound this good,it's impossible,but good design with quality parts and your jaw might just be on the floor.

No I did not measure these parts or the 350's at the beginning or the end, my tech said the sine wave was about as perfect as it gets. Was I lucky? No I just did a lot of experimenting and listening, hard work but fun. I bet Nelson Pass voices every component that goes in to every one of his designs and yes they all build to a price point.

p.s. About the only measurement I look at anymore is the A weighted S/N ratio figure. The Lamm 2.1 preamplier measures -94db,not bad,but if it was -100 I would be impressed.

The fact is Tom has rejected those olive branches Roger. I look at specs. and measurements not so much to predict the sound of the amp, but to assure it s capable of driving the speakers I am mating it with.

 

[Phelonious Ponk]

Give me a colored hodge podge that in the end whose measurements hews closely to the original waveform in actual use to one that all measures supposedly flat individually but falls on it's face when measured from the listening position. In practical terms it's nothing but a security blanket or a crutch.

We're going to have to agree to disagree on that one, Jack. Getting that colored hodgepodge to balance in the end is a painful, if even possible, exercise. And if all the components in your system measure flat and you have a mess at your listening position, you need to look at your transducers and your room, not your electronics. MHO. YMMV.

It seems to me that the common audiophile approach is to buy individual components from individual builders and build a system that seeks "synergy." That synergy could mean a fairly accurate representation of the recording or whatever pleases the owner. Fair enough. Enjoy.

My personal approach is to seek neutrality and compatibility, and all the measurements I can get are valuable tools in that search. I save the color for the transducers and the room, where it cannot be avoided anyway. What I gain from this is efficiency and the confidence that I have a pretty clean, uncolored signal at the speaker terminals. What I lose is the entire hobby that is built up around "getting the colored hodgepodge to balance" -- the buying, selling, trading, upgrading...the excitement of having a new piece of gear and waiting to hear the impact it will have on my system, in my room. If you seek neutrality and compatibility in electronics, and you're pretty good at it, that moment, when you put the new component in your system and you use the ultimate tool, your ears, tends to be pretty anticlimactic. You put the beautiful new component in the system, turn it on...and it disappears.

I've come to love that lack of drama. But I completely understand that it would just suck all the joy out of the hobby for many.

Tim