Active Speakers

[Nevalti]

Your point is well made Gordon. ANY comparison is, in a sense, an A/B test or perhaps an A/B/etc test.

The A/B testing that has been presented to me to 'prove' that there is no difference, is playing some music and switching from one amplifier (etc) to another without me knowing which is in use. This 'test' does indeed show that with simple sources and at low volume, there is little difference between amplifiers. Such a test, with the source(s) and venue chosen by the demonstrator, proves nothing when it comes to real-world listening. You can easily do exactly the opposite and choose a source which is genuinely taxing on an amplifier's abilities. Then you may well get a huge differences between what you hear via each amplifier BUT when the going gets easy again, it is quite possible that you don't like the presentation of the 'best' amplifier on the difficult passage. [Example: I had a demonstration of a particular Arcam pre/power combination in my lounge and was staggered by just how good the bass presentation was - fast, detailed, etc. It was, and still is the best I have ever heard in my lounge. Sadly, when I left it playing on more beautiful music, it killed it stone dead. It was unlistenable for me.]

I don't think any of this is difficult to understand, or indeed to hear, yet we continually have people who claim that there is no difference and that audiophiles are taken in by sales hype. I'm sure some are but many go to a great deal of trouble to achieve the best possible music in their homes. Sadly, many of the nay-sayers keep referring back to specification, as if that proved anything. The only thing that counts is what you hear and if someone can't hear any difference - lucky them - they can save lots of money.

[Nevalti]

Sorry Gordon, I have only just spotted your attachment (I'm colour blind).

I'm certainly not going to read it all but there seems to be a lot of sense in that document including the recognition that some people CAN hear things that others cannot. Unfortunately, those who cannot hear as well usually do not believe that other people can hear rather more that they can. They seem to be the nay-sayers.

I disagree with one suggestion, that is that ONLY 'critical' sources are used for comparison purposes. As detailed in my last post, an amplifier may be great at some things and rubbish at others - so you do need to test all aspects of its performance.

[Gordon]

Sorry Gordon, I have only just spotted your attachment (I'm colour blind).

I'm certainly not going to read it all but there seems to be a lot of sense in that document including the recognition that some people CAN hear things that others cannot. Unfortunately, those who cannot hear as well usually do not believe that other people can hear rather more that they can. They seem to be the nay-sayers.

I disagree with one suggestion, that is that ONLY 'critical' sources are used for comparison purposes. As detailed in my last post, an amplifier may be great at some things and rubbish at others - so you do need to test all aspects of its performance.

Good Lord we are in some agreement, at least here, not sure about the DAB Report thread!! There is a recognition in the profession that some are better than others at hearing small differences - I knew an engineer at BBC Research who was exceptionally good at hearing PCM/compression type coding artifacts but never did exceptionally at other tests done under BS1116. Same applied to a couple of my research team's members doing the same sort of thing. I think their ears were attuned to specific defects and perhaps that is what also happens to non experts with good ears with time and exposure. But then are people's moods, frame of mind, health etc going to get in the way of long term consistency anyway?

The challenge, as it were, to those peoples' abilities is that they should be able to demonstrate it by consistently out-performing the average almost regardless of context. What if they don't? Do we then claim that the test methodology is necessarily wrong? Well of course that is what some of them do!! However, if they do, under those same tests, then of course the methodology must be correct!! The object of the tests is to understand the human auditory system not to prove that golden ears don't exist. Not hard is it?

The context of that document is revealed in the title - the "critical" material is recommended when looking for small differences that perhaps only experts can find and so it needs material that will bring those out. Normally when designing these tests the context is taken into account and normally a range of "easy" and" hard" material - chosen because the material is known - is selected.

The intriguing thing is why does this behaviour occur? As engineers and scientists we of all people ought to be interested. There is an implication that we don't fully understand what is happening in our audio system designs. The circumstantial and anecdotal evidence suggests that this is so. Your own words for example:

"....choose a source which is genuinely taxing on an amplifier's abilities. Then you may well get a huge differences between what you hear via each amplifier BUT when the going gets easy again, it is quite possible that you don't like the presentation of the 'best' amplifier on the difficult passage. [Example: I had a demonstration of a particular Arcam pre/power combination in my lounge and was staggered by just how good the bass presentation was - fast, detailed, etc. It was, and still is the best I have ever heard in my lounge. Sadly, when I left it playing on more beautiful music, it killed it stone dead. It was unlistenable for me."

From an engineering point of view this sort of thing is a challenge. Some rhetorical questions: Why should these experiences exist? What does "taxing...an amplifier's abilities" mean here? Surely, for example, you would not test an amp at power levels out of its stated design range or into a speaker that cannot take that power either? What possible effect does the source or load have? What is "difficult" about certain passages? One can ignore all these things and resort to endless listening as people do but it behoves us to try and do better than that.

Even the subjectivists in the audio field surely should also be curious as to why some systems sound better to them than others, but not tp other people, and why some material sounds better on some systems than others. Without a bit of rigour and objectivity it may as well be snake oil and the charletans win.

[Nevalti]

......The challenge, as it were, to those peoples' abilities is that they should be able to demonstrate it by consistently out-performing the average almost regardless of context. .......

I am extremely aware that my eye-sight deteriorates during the day, also my body literally sags so that I have my driver's seat and rear view mirror in a different position morning and evening. It is a small leap to assume that my hearing, and other people's, similarly varies for a variety of reasons, not least their health.

My concentration, when critically listening to equipment, is very different from my relaxed listening to get pleasure from the music. I would suggest that we all have varying levels of listening, viewing, smelling, feeling, etc dependant upon what we want to achieve. It is rather like proof-reading. We will all recognise a misused word (their or there for example) but if you are not concentrating on spelling, you may miss it in the pleasure of reading the book. We humans can not be consistent, we are too easily distracted.

What does "taxing...an amplifier's abilities" mean here?

I certainly don't mean taking it to its limits - where it will obviously sound poor. I meant, playing a musical passage that makes demands upon the amp to remain clear and clean when it is trying to reproduce complex music. The crescendo near the beginning of Mahler's 5th for example can easily sound a noisy mess. One of the best tests for this is Dire Straits 'The Man's Too Strong' where the loud bits can easily sound awful until you hear it on good equipment. For example, there is a quietly strummed guitar continuing right through the noisy bits but it can completely disappear with some amps. I have no idea why - simply that it happens.

Without a bit of rigour and objectivity it may as well be snake oil and the charletans win.

Similarly, claiming one can choose equipment purely from specification is also the province of charlatans.

[Phileas]

I meant, playing a musical passage that makes demands upon the amp to remain clear and clean when it is trying to reproduce complex music. The crescendo near the beginning of Mahler's 5th for example can easily sound a noisy mess. One of the best tests for this is Dire Straits 'The Man's Too Strong' where the loud bits can easily sound awful until you hear it on good equipment. For example, there is a quietly strummed guitar continuing right through the noisy bits but it can completely disappear with some amps. I have no idea why - simply that it happens.

There's nothing to stop these passages being used in a blind ABX test.

Similarly, claiming one can choose equipment purely from specification is also the province of charlatans.

I think the relevant claim is that many of the apparent differences between properly designed electronic audio components disappear under blind ABX test conditions.

[jayne lee wilson]

There's nothing to stop these passages being used in a blind ABX test.



I think the relevant claim is that many of the apparent differences between properly designed electronic audio components disappear under blind ABX test conditions.

The trouble with your ABX ideal is that a given listener doesn't know what she's listening for, especially in that very good example of Mahler 5 Nevalti cites (another good example would be the end of Hindemith's Harmonie der Welt, the passacaglia - not many systems can sort THAT out... I should know - I used to own one of them). This could as easily blunt her perceptions as anything else, if all she's asked to do is note "differences". Classical listening is longterm and quite a complex skill. In practical terms, how often can one listen to such loud and complex passages before fatigue sets in, or indeed before greater familiarity with the music changes your perception of it?
Not to mention the fact that such strictly-controlled ABX testing will almost never be possible in the personal choice of an audio component. If you then argue that the conclusions of the tests you clearly believe in should condition your choices, you are putting theory (however well-evidenced) before actual listening.

Again Phileas, you use this impersonal mode "apparent differences.... disappear under blind ABX conditions." Who says so, with what final, grounded authority? And how presumptuous is that "apparent". (One could as logically suggest that "real" differences disappear under such conditions.) And this would hold true even if you could adduce a well-evidenced, peer-reviewed paper on the subject, especially given the small number of such experiments carried out and reported. The next test might produce different results.

[Nevalti]

There's nothing to stop these passages being used in a blind ABX test.

The recommendation in Gordon's report was that only 'critical' music was used. I disagreed with that and gave my reason above. Are you really suggesting that one can or should make a purchase or a design decision based on a 10 second passage(s)? Are you suggesting that a sensible purchase decision should be based on the opinions of a listening panel rather than what your own ears tell you?

I think the relevant claim is that many of the apparent differences between properly designed electronic audio components disappear under blind ABX test conditions.

... and so the circle starts again. What does "properly designed" mean exactly? Something that sounds right or something that measures well? Just how well does it have to measure to be classed as "properly designed"? If you conclude that manufacturer 'a' or 'b' 'properly designs' things, are you then willing to buy from them without bothering to listen to them first?

I have heard rather too many highly recommended components sound very ordinary or even downright poor. I see no alternative to using my own ears, not a listening panel, no matter how golden their ears and I certainly wouldn't rely on specification to tell me how something will sound.

[Phileas]

The trouble with your ABX ideal is that a given listener doesn't know what she's listening for

I'm not sure if we're at cross purposes here Jayne. I'm just talking about ABXing to establish whether differences are audible, not for choosing components. All the listener has to do is try to hear differences which is best done (as far as I understand) using very short excerpts.

The next test might produce different results.

But what if a point has been reached where audio technology has far surpassed the ability of humans to detect audible differences? Why would someone not trust competent designers to employ the technology correctly? (State-of-the-art DAC chips cost a few quid.)

Why would someone trust the "evidence of her own ears" using sighted comparisons when it's well established how fallible and suggestible all humans are?

PS - I'm undecided about audible differences between power amplifiers as this may depend on the speaker loads they're connected to.

[Ferretfancy]

In my job I needed to compare the incoming signal with the recorded signal by means of a changeover switch on the desk as we mixed the tracks and edited the dub.
On one occasion at the Evesham training school we were given a demonstration of Dolby ( these were early days ) using two carefully carefully adjusted tape machines matched for level. The recording was of a solo soprano and piano, nicely balanced. One machine had a normal non Dolby version, the other, which had been made simultaneously, carried a Dolby / De-Dolby version, and both tapes were originals.

I was in a group of a dozen or so sound recordists, together with a close colleague, and we were invited to flick a switch and do rapid comparisons. To my colleague and I it was apparent straight away that the soloist sounded slightly closer in the balance on the Dolby version, but none of the sound recordists spotted the difference.
This didn't make us golden ears, it was simply that we made such comparisons all the time in our work, and the recordists working on location did not, or at least less frequently. In other words, subjective judgement can be learned, and different people will have different aptitudes

[Nevalti]

......I'm undecided about audible differences between power amplifiers ..............

Fair enough. That's a good start.

Recording engineers use carefully chosen amplifiers (and speakers) to reveal, to them, as much as possible of the recording from which to make their production assessments/decisions. Once they have made the adjustments that they consider appropriate, they then listen to their creation using less capable amplifiers and less capable speakers. Why would they do that if they all sounded the same? Are they kidding themselves or do they have a good reason for their choice of equipment?

Commonly used professional amps are ATC and Bryston both of which are excellent but not necessarily the best hifi available. Nevertheless, I honestly don't think that anyone without a hearing defect could compare an ATC or a Bryston with similarly specified equipment from a cheap manufacturer (insert almost any Japanese name) and not notice the difference.

Is there a recording engineer here who can offer his opinion?

[Phileas]

Recording engineers use carefully chosen amplifiers (and speakers) to reveal, to them, as much as possible of the recording

I believe rather a lot of recording engineers use active speakers.

[Nevalti]

I believe rather a lot of recording engineers use active speakers.

Yes, they do. Often ATC & Bryston/PMC active speakers costing more than most cars. A far cry from domestic active speakers costing a few hundred pounds. Fortunately they can afford to replace them regularly as improvements become available.

Active speakers have the potential advantage of separating the signal before the amplifiers and not needing a passive cross-over. They are very sensible PROVIDING you are prepared to buy new instead of simply upgrading a component - and of course providing you can find someone willing to allow you to audition them.

[Phileas]

Yes, they do. Often ATC & Bryston/PMC active speakers costing more than most cars. A far cry from domestic active speakers costing a few hundred pounds.

Implying that expensive=good and cheap=bad.

But we're going round in circles again...

[Nevalti]

Implying that expensive=good and cheap=bad......

Well sir, you seem to be implying that £50 or £500 or £1,000 active speakers will sound as good as £50,000 active speakers? I expect some people think that a Ford Fiesta is just as good as a Rolls Royce too.

It is obviously a fact that some active speakers will sound better than some separates system. Little iAudio or Yamaha active speakers, for example, provide amazing performance for peanuts. The problem is that you have absolutely no ability to 'tune' active speakers to suit your source or your room. If it doesn't sound right - tough. You have to change the room or change the source - or of course get rid of the active speakers (modern radiogram).

[clive heath]

Excuse my ignorance but I didn't know you could tune passive speakers themselves. You can modify the signal sent to the speaker system with a graphic equaliser (analogue or digital) but that applies to all speaker systems. What am I missing?