How do you judge your system's neutrality?

Cbw, my interpretation of Bryon's posts has been that he wants to find common ground on neutrality among all audiophiles and all systems, not just within each individual's own system. Please correct me, Bryon, if I am wrong, but I don't think I have been the only one putting that interpretation on the original post! By the way, Cbw, that is a fascinating discussion of entropy in your last post.

Dgarretson has some interesting additions, as well, though much of it I either don't understand or would disagree with. For instance, when you say that "continuousness" is "consistency of musical expression throughout the frequency range." Not sure what you mean by this. My first reaction on reading it is to say that no acoustic instrument (including the voice) has consistency of "expression" (assuming you mean things like timbre? volume?) throughout it's full range. If they were made to sound as if they did, it seems to me this would be a violation of what you guys are calling "neutrality?"

I am also not certain that your concept of "organization" is not another form of "coloration," since you are speaking of "small corrections to pitch and timbre, improved transients and decay against a quieter background." Corrections from what, exactly?

While I would agree with you that "warm" and "analytical" are not mutually exclusive, I would strongly disagree with the notion that there is no such thing as too much resolution. Just one example. Almost all orchestral recordings made today are done with too many microphones set up, in the musician's opinions, far too close to our instruments. The vast majority of the mix uses these mikes instead of any placed overhead, and many engineers don't even put any out in the hall anymore. The resulting sound of the recording is nothing like what a concertgoer actually hears, no matter where they are seated in the hall.

I realize that you are speaking of the resolution of the system, but many high end systems I have heard create a very similar effect on a recording that was done well. And whether this bothers someone or not would be down to their personal preference as well (so is the statement that the recording was "done well," for that matter). This has been discussed in a different thread before, the idea that many audiophiles assume that some "colorations" they are hearing are caused by their system, when in fact they are on the recording itself. I have seen more than one situation where two people could not agree on which was the case ("Well in MY system, it doesn't sound like that!" etc). This is yet another reason why I don't think there could ever be much agreement on any two people's sense of "neutrality." There are far too many subjective variables, no matter how well we could define colorations on the page.

A little while back, Al suggested substituting another term, such as ‘accuracy,’ for the term ‘neutrality.’ More recently, Cbw mentioned that, when reading my posts, he tends to substitute the term ‘distortion’ for ‘coloration.’ And Learsfool has argued in many different ways that ‘coloration’ is a subjective category.

I believe that these three points of view are related, in that they all identify the same shortcoming in my definition of coloration, namely: It makes ‘coloration’ too OBJECTIVE a category. Here is the definition of ‘coloration’ I have been working with:

COLORATION: Additions, subtraction, and alterations to the playback chain that conceal or corrupt information about the music.

I think Al was correct in his view that the above definition is close to a definition of ‘inaccuracy.’ I think Cbw was also correct in his view that the above definition is close to a definition of 'distortion.' And I think Learsfool was correct in his view that the above definition is not subjective enough.

For these reasons, I would like to propose four things:

(1) Following Al’s advice, we make my former definition of ‘coloration’ the new working definition of ‘inaccuracy.’

INNACCURACY: Alterations to the playback chain that eliminate, conceal, or corrupt information about the music.*

*There are two other slight changes to this definition. I have changed “additions, subtractions, and alterations” to simply “alterations,” since all additions and subtractions are necessarily alterations. I have also included “eliminate” with “conceal and corrupt,” since the former seems to be just as much a possible type of inaccuracy as the latter.

(2) In the spirit of Cbw’s substitution, we identify distortion as one of the determinants of inaccuracy:

DETERMINANTS OF INACCURACY: Various kinds of distortion, loss, and noise, such as jitter, crosstalk, intermodulation distortion, speaker cabinet resonance, phase shifts, room modes, comb filtering, flutter echo, etc.

(3) Acknowledging Learsfool’s objections, we make the definition of ‘coloration’ more subjective:

COLORATION: Inaccuracies audible as a non-random** sonic signature.

This new definition entails that COLORATION IS A TYPE OF INACCURACY, the type that results in an audible, non-random sonic signature. It is consistent with the existence of other types of inaccuracies that do not result in an audible, non-random sonic signature.

This new definition also makes the term ‘coloration’ somewhat more SUBJECTIVE, since it includes FACTS ABOUT THE SUBJECT, by employing the concept of ‘audibility' (more on this below).

**I almost said “constant” sonic signature, rather than “non-random,” until I read Cbw’s recent post where he reminded me that many colorations vary with frequency, and so are not, strictly speaking, "constant." So it is more precise to say that colorations are non-random, or what Cbw calls, “predictable, in that their affect on a signal may be known.”

(4) The definition of 'neutrality' stays the same, namely, the degree of absence of coloration.

There are two advantages to the proposals expressed in (1)-(4). The first is that these definitions more closely reflect audiophile usage. This is evidenced by Stereophile’s audiophile dictionary. It is by no means definitive, but it is a relevant data point concerning usage:

Accuracy: The degree to which the output signal from a component or system is perceived as replicating the sonic qualities of its input signal. An accurate device reproduces what is on the recording, which may or may not be an accurate representation of the original sound.

Neutral: Free from coloration.

Coloration: An audible "signature" with which a reproducing system imbues all signals passing through it.

You can see these definitions at the following link:
http://www.stereophile.com//reference/50/index.html

The second advantage of these new proposals is that they bring the conflicting views of the Objectivist and the Subjectivist one step closer together. It is only a step, though, since the new definition of ‘coloration’ I am proposing is only subjective in the sense that it includes facts about the subject, facts that, I believe, are themselves largely OBJECTIVE. So this is not a retreat from Objectivism, so much as it is an acknowledgement that understanding coloration and neutrality is partly a matter of understanding HOW INACCURACIES ARE PERCEIVED.

(1) Decreasing entropy = Increasing predictability.
(2) Increasing predictability = Increasing coloration.
(3) Increasing coloration = Decreasing neutrality.
.....Therefore:
(4) Decreasing entropy = Decreasing neutrality.
.....And also:
(5) Preservation of entropy = Preservation of neutrality.

Is this correct?

Yes, that is essentially the argument. #1 and #3 are by definition. The reason for #2 is I am asserting that the coloration processes are not stochastic. This assertion is consistent with the definition you quoted from Stereophile:

Coloration: An audible "signature" with which a reproducing system imbues all signals passing through it.

Which is to say that colorations are replacing/concealing/corrupting musical information with a "signature" (i.e., more predictable information).

This understanding of the entropy-neutrality relationship is somewhat in contrast to something I wrote earlier (first quoting Dgarretson):

Relating to continuousness, movement toward neutrality implies a more organized presentation.

This is an interesting notion. If we consider the source as maximally organized information, then each stage in the audio chain has the potential to disorganize some information. The extent to which we don't corrupt the information determines the organization of the final presentation. So for a system, the greater its neutrality, the lower its entropy.

Here I was talking specifically about the entropy of the musical organization. However I failed to consider that the colorations were, in fact, more organized than the music. So while the music was becoming less organized *as music*, the overall presentation was actually more organized (i.e., it had lower overall entropy). So I had mistakenly reversed the neutrality-entropy relationship.

Bryon writes:

INNACCURACY: Alterations to the playback chain that eliminate, conceal, or corrupt information about the music.

My only problem with this definition (aside from the typo) is a nit pick: "Alterations to the playback chain..." sounds like you are talking about changes to the hardware. More precise might be something like, "Alterations to the source (or music) as it passes through the playback chain..." and then drop "...about the music." Or maybe just change the word "to" to "within."

COLORATION: Inaccuracies audible as a non-random** sonic signature.

I very much like this definition as it closely matches my thinking about what a coloration is, without the restrictive "narrow band" constraint that I was considering.

A fuller extract of ideas from G. Holt’s audio glossary seems relevant in context:

1. Frequency response: Phase shift and distortion can sound like frequency-response aberrations.

(Note 1: Perception of neutral frequency response may be subjectively similar to perception of low distortion and correct phase. One is therefore be tempted to use the term neutrality in all three contexts.)

2. Balance: The subjective relationship between the relative loudness of the upper and lower halves of the audio spectrum; "tonal balance."

3. Coherent: seamless from top to bottom… no audible evidence of different… colorations in different frequency ranges.

4. Continuity: Uniformity of coloration (across the operating range).

5. Discontinuity: A change of timbre or coloration due to the signal's transition (across the operating range through) dissimilar coloration.

6. Seamless: Having no perceptible discontinuities throughout the audio range.

(Note 2-6: He identifies colorations as shifts in tonality across the frequency range. My previous reference to neutrality as “continuousness of musical expression across frequency range” was an attempt to describe this. I question whether there can really be such a thing as continuous coloration, positing instead that inevitable variations in coloration across frequency range indicate unsolved problems in the playback system. To distinguish problems in playback from problems in recording, the trained listener merely needs to listen to a wide variety of recordings on the same playback system.)

7. Pitch resolution: The clarity with which pitch…is perceived. Poor pitch resolution makes all notes sound similar…

(Note 7: Here he touches both on Bryon’s original notion of coloration as a failure to differentiate, and on Cbw723’s remarks on Shannon entropy.)

8. Fast: Reaction time, which allows a reproducing system to "keep up with" the signal fed to it. (A "fast woofer" would seem to be an oxymoron, but this usage refers to a woofer tuning that does not boom, make the music sound "slow," obscure musical phrasing, or lead to "one-note bass.") Similar to "taut," but referring to the entire audio-frequency range instead of just the bass.

9. Smooth: Not necessarily a positive system attribute if accompanied by a slow, uninvolving character.

10. Control: The extent to which a (system) sounds as if it is "tracking" the signal being fed to it. The sound is tight, detailed, and focused.

(Note 8-10: Here he identifies fast & controlled dynamics as essential to an uncolored presentation. Absent precise dynamics, differentiation is lost (e.g. “one-note bass.”))

11. Definition (also Resolution): That quality of sound reproduction which enables the listener to distinguish between, and follow the melodic lines of, the individual voices or instruments comprising a large performing group.

12. Detail: The subtlest, most delicate parts of the original sound, which are usually the first things lost by imperfect components.

13. Veiled, veiling: Pertaining to a deficiency of detail and focus, due to moderate amounts of distortion, treble-range restriction, or attack rounding.

14. Focus: The enhanced ability to hear the brief moments of silence between the musical impulses in reproduced sound.

15. Hangover: A tendency for reproduced sounds to last longer than they should.

16. Ringing: The audible effect of a resonance: coloration, smear, shrillness, or boominess.

(Note 11-16: Higher resolution defined in this sense a good thing, and is connected by Holt to Bryon’s original notions about the distinction of differences. Interestingly, the related quality of Focus entails removal of additive colorations so as to reveal interstitial silences. Also, Holt connects compromised resolution to “attack rounding”—or failed dynamics.)

17. Error of commission: Signal degradation due to the addition of sounds that were not present in the original signal. Distortion and coloration are examples of errors of commission.

18. Error of omission: Signal degradation due to the loss of information that was present in the original signal. Smearing and treble loss are examples of errors of omission.

19. Gestalt response: The evocation of a complete memory recognition by an incomplete set of sensory cues. A gestalt response to the few things an audio system does outstandingly well can make imperfect reproduction seem more realistic than it actually is.

(Note 17-19: Here he gets into interesting territory similar to Bryon’s ideas about coloration as additions, subtractions, or alterations. I think we may conclude that Holt regarded coloration primarily as an error of commission. The idea about Gestalt response is fascinating insofar as he suggests that absent errors of commission, a less than fully resolving playback system may be convincing and perhaps even uncolored in the strictest sense of the word.)

20. Neutral: Free from coloration.

21. Uncolored: Free from audible colorations.

Finally, Holt used the terms Subjectivism and Objectivism in a particular sense. Subjective reviewing is his term of art for critical observation based on controlled listening, psychoacoustics, and a precise vocabulary to evaluate colorations. He considered Objectivists to be the so-called “meter men” test bench-oriented reviewers of Julian Hersh school who tended to ignore the science of listening. Holt’s Subjectivism is not inconsistent with objective analysis. As he says in the glossary, given a precise definition of terms “there is no longer any excuse for an audio reviewer saying, ‘I can hear a difference, but there's no way of describing it.’ Now, there is a way.”

So Holt's view was that audible colorations can be precisely described, and if inaudible, do not exist.

Learsfool wrote:

This has been discussed in a different thread before, the idea that many audiophiles assume that some "colorations" they are hearing are caused by their system, when in fact they are on the recording itself. I have seen more than one situation where two people could not agree on which was the case ("Well in MY system, it doesn't sound like that!" etc). This is yet another reason why I don't think there could ever be much agreement on any two people's sense of "neutrality."

Like many people, I have had this experience both with audio and video. While in video, a proper calibration usually clears up the ambiguity between software colorations and hardware colorations, I agree that, in audio, it's not so simple. But again, I'm more optimistic about the possibility of some agreement some of the time. It's also worth pointing out that my proposed operationalization of neutrality does not require us to be able to differentiate software from hardware colorations as such. It only requires us to make judgments about how much differentiation a system is capable of.

In the case you mention, where variations in the sound of the same software on two different systems leads to ambiguity about software vs. hardware colorations, my method of determining neutrality offers a potential solution to the deadlock. By determining which system has greater differentiation, particularly in the domain where the ambiguous coloration occurs (e.g., instrument timbre), you can conclude which system is the more neutral of the two. If the coloration in question does not occur, or occurs less, on the more neutral system, then it is likely to be a playback coloration added or aggravated by the less neutral system. This method is, of course, fallible. But I believe it is useful for providing clues to distinguishing software colorations from hardware colorations. And if you were willing to move equipment around, the same method could be employed for distinguishing equipment colorations from room colorations.

Cbw - Your suggestion about revising the definition of 'inaccuracy' is a good one. Will work on it.

Dgarretson - I have a question for you about Cbw's entropy theory and your first operationalization of neutrality, namely, the idea that increasing neutrality results in increasing source convergence. Would Cbw's explanation of coloration in terms of decreasing entropy explain the convergence you predicted? And since his explanation extends to the entire playback chain, should we predict that, as whole systems become more neutral, they will sound more and more similar to one another?