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[Andrew L. Weekes]

This method cannot work, because over the long term, the non-sonic factors will change radically. Your health will change from one day to the next; you may have had a row with your spouse/partner/children; and so on.

Actually I am in total agreement with you in that your personal mental and physical state do have a significant and even dominant impact on what you perceive, but would argue that over the long term my experience is that as an evaluation method it works.

The 'off days' are a problem, but they are always outnumbered by the good days, which means I am able to make an accurate judgement.

The fact is that the 'off days' result in everything sounding 'bad' but on the 'good days' one can make an accurate judgement - bad stuff doesn't suddenly become good, in my experience, just because I feel great.

The only area where I disagree is that the curent state of audio design is one where the human element dominates, I profoundly (but respectfuly) disagree here.

As it curently stands, for example, the SB2 is not something *I* could be happy listening to for my daily musical fix, but I have little doubt it can become one, based on brief experiments thus far.

In fact I'm *really* hoping it will, I like the in your face, radical two fingers it sticks up to the overpriced, underperforming mass that curently is the 'high end' or whatever you'd like to call it.

Again my experience here is everyones expectations are different - there's almost no absolutist 'right' answer for everyone, we all have different levels of what is sufficient to press our musical buttons, and different things bother different people. I accepted this a long time ago, hence my total lack of evangelism with regard to this, I found a lot of people who like what I do, but am happy to accept that as many others may hate it with avengeance!

So back to the ABX thing, I have no problem with anyone who uses that to evaluate their changes, but for me it's not a lot of fun or very effective in my view - I'd rather just listen to (and hopefully enjoy) music! Just please don't try and convince *me* that I cannot be hearing what I hear, when I'm happy that you are totally happy with your position. I'll continue to present my experiences, which anyone may test in any manner they see fit.

Good discussion anyway, it's nice to see such reasoned participation against the backdrop of what these discussions so often degrade into.

:-)

Andy.

[Fabrice Rossi]

Very interesting post, Andy.

Andrew L.Weekes wrote:
> I know I said I wouldn't get involved, but since you do seem genuinely
> open-minded (and I may have mis-interpreted your response) I'll make a
> comment, if I may ;-)

My response was a bit strong, because I'm quite annoyed by the fact some
hifi gear cost a lot and then you are supposed to buy a lot of fancy
stuffs (like high end PSU) to get the most out of them. It seems to me
that more care should be exercised by the designers of this gears. For
instance, if you pay 1000 $ for a DAC, it should include a nice PSU.
When I see the very careful design that has been done for the SB 2 that
costs almost nothing for such a good product, I'm really thinking about
rip off for some other products.

> I wouldn't say it's bullshit myself, simply mis-applied to the job in
> question. The problem for me with ABX is it doesn't take into account
> the way we hear music, which is not through some short-term effect in
> the ear, but a longer term effect in the brain.
>
> For most of us music is all about emotions; dancing, singing, happy,
> sad, angry, agressive, soft etc. That's the whole raison d'etre for
> it's existence and why musical -artists- do what they do. To break it
> down to simple measurement is like digitising a great painting and
> assessing the range of colours or the contrast etc Our ears know
> nothing about the emotional effect music has on us, that process
> happens in the brain.

I guess we agree on that. And this applies also to wine, tea, coffee and
a lot of other things.

> Some of the best scientific work in this field comes from Hugo Fastl
> and the late Eberhard Zwicker - their publications and work are
> ammassed in Psycho-acoustics - Facts and Models, which isn't exactly
> light bedtime reading, but is fascinating nonetheless.

Do you have complete references, I'd like to read this kind of work.

> The ABX test forces us into trying to listen for a difference, usually
> in an inherently short-term fashion, by rapid switching. Thsi is not
> how we listen to music, which is a long term event by comparison.

Well, you are not forced to do rapid switching when doing ABX. This is
the way many people are reacting to ABX because they feel pressured, I
think. But you really can spend one hour (or more, of course) listening
to A, same thing for B and then again X.

And by the way, this is the same thing for wine. Wine tasting has almost
nothing to do with wine drinking. However, it is a accepted way of
judging wines (more on that latter).

> The reason is that hearing takes place in the brain, not in the ears.
>
> Hearing is related to data processing in the brain and makes use of
> enormous amounts of previously stored data and complicated adaptable
> data processing schemes. Therefore hearing fundamentally makes use of
> the long term memory were all those data sit.

You should be careful with this sort of statement. With non invasive
brain monitoring, it is indeed possible to test what part of the brain
(short memory, long memory, etc.) is used to perform a given task. I
don't know if this kind of experiments have been conducted for hearing,
but this could be done and this statement (critic hearing uses long term
memory) can be tested (I do believe that you are right). If this has
been done, I'll be pleased to have references.

> Hearing is only partially related to the gathering of audio data in the
> ear and the primary storage of those data in sensory memory, which is
> short term.
>
> Now in a rapid switching DBT you want to make an "objective" test by
> deleting the huge data processing part of the hearing equation which is
> related to long term memory, because the rapid switching prevents the
> long term memory from being activated.

That's simply not true. The only explanation we have for the amazing
performances of professional wine tasters is that they are indeed
relying on long term memory to recognize wines and to compare the one
they are tasting with the huge library of smells and tastes they have in
mind. I don't have references, but I'm almost sure some brain imaging
experiments have been done on this. And the nice thing is that they do
it very very quickly. Trained wine tasters can identify several
different wines in one minute.

Long term memory can be recalled very quickly. So the problem is here to
store A and B on this long term memory. Several minutes of careful
listening will do the trick. Remember that you don't have to do rapid
switching, you can listen for a long time to A, then to B (and then back
to A, etc.).

> Take out this "subjective" part
> of hearing and what's left is the "objective" part related to short
> term memory, ain't that true?
>
> No.
>
> Take out the data processing part and nothing serious is left of
> hearing: no dataprocessing in the brain means no audio image reaches
> our consciousness which means no conscious judgement can be made.
>
> The curious thing is that in such a DBT you STILL want the test person
> to make a conscious *subjective* judgement (a judgement on personal
> experiences is by definition subjective).
>
> So you want the test persons to give their subjective judgement on the
> data collecting process in the ear plus short term sensory memory
> storage process. But nobody can do that.
>
> The subjective judgement canonly be made by our consiousness, and our
> consiousness has no knowledge of the early processes of hearing.
>
> It's one of the reasons that level matching is deemed so critical,
> since that is one of the few things the early processes of hearing can
> determine - remove it and the tests differences often vanish.
>
> To that end, I DO believe that double blind testing can work, but that
> it has to be inhernently long term - the comment Partick made earlier,
> about whether you are glued to the seat listening to music that engages
> you, or would rather be watching the TV, is the best measure by far in
> my view.
>
> I think that if one allowed the listener to listen to each item for a
> long period (and here I'm thinking several days per item) then it's
> possible that a DBT, or an ABX could be made to function reliably. So
> I'm not anti science at all, but I do believe that the way it is often
> proposed is fundamentally flawed.

How long do you need to learn a piece of poetry? I don't think that you
need days, a couple of hours will suffice for some short poem. If you
already are very familiar with some music, I think you can "learn" the
way it is reproduced by a device in a couple of hours or less, and then
compare this (using long term memory) with the way it is reproduced by
another device.

> So why don't I try it out?
>
> Simply because using the long term evaluation, the results become
> obvious; whether a particular change is better or not becomes obvious,
> simply owing to the amount of music I listen to - if i find myself
> still up at 2 in the morning when I have work the next day, it's
> usually a good sign

Well, well, well. I think you are familiar why the reason why double
blind tests are used for drug testing. The placebo effect (which
demonstrated beyond reasonable doubt). The mind is so strong that it can
boost your immune system enough to heal you if it believe that the water
pills you are taking is indeed a drug (so blind tests are needed). Even
more, it can guess the reality of the pills being a drug by analyzing
the body language of the medical staff (so double blind tests are
needed). So maybe ABX double blind do not work, but then nothing does.

Fabrice

[cliveb]

Clive, I have to disagree, the same reasons you give also apply to short term A / B listening. One's personal health and mental state will also affect the listeners perception, with short term listening the 'risk' or 'error' is greater for the listener.

Surely the chances of a listener's health/mental state changing will be lower over a shorter period of time? If you carry out a comparative test over the course of days, there is virtually no chance at all that these non-sonic factors will remain constant. But if you do a test over the course of a few hours, they are less likely to change. And since the purpose is to try and do some sort of scientific test, you have to try and eliminate as many external variables as you can.

Of course, an intensive ABX test is rather stressful, and many people would argue that this in itself is a non-sonic factor that overwhelms any differences one would otherwise notice in a more relaxed environment - hence the large number of negative results. It may be this issue that you're referring to when you say that the 'risk' is greater in short-term listening. As far as I'm concerned, this is the only valid criticism one can level against ABX, because everything else it sets out to do seems pretty logical to me.

[cliveb]

So back to the ABX thing, I have no problem with anyone who uses that to evaluate their changes, but for me it's not a lot of fun or very effective in my view

And it's also a heck of a lot of hassle to set up properly if you're trying to compare things like PSUs.

Just please don't try and convince *me* that I cannot be hearing what I hear, when I'm happy that you are totally happy with your position.

Hey, I would never do that, because it is tantamount to telling people they are lying. My position is one of trying to come to some understanding about why people (including me) do genuinely hear differences between equipment which cannot be distinguished under ABX conditions. There's no shame in allowing oneself to be influenced by external factors: it's only human nature, after all.

[Fabrice Rossi]

cliveb wrote:
> NealG Wrote:
> Of course, an intensive ABX test is rather stressful, and many people
> would argue that this in itself is a non-sonic factor that overwhelms
> any differences one would otherwise notice in a more relaxed
> environment - hence the large number of negative results. It may be
> this issue that you're referring to when you say that the 'risk' is
> greater in short-term listening. As far as I'm concerned, this is the
> only valid criticism one can level against ABX, because everything else
> it sets out to do seems pretty logical to me.

I question the validity of this criticism, again with the wine analogy.
I've witnessed blind testing of wines by some highly trained sommelier
and they do operate under _very_ stressful condition. This is in general
a competition for some title like best sommelier of the world, the tests
are extremely difficult (like recognizing completely a wine, including
vintage), they have very limited quantities of wine to taste, and yet
the tests are passed by those professional sommeliers. And remember the
wine tasters do not have to test for differences, they have to recognize
a wine they might have tasted years ago.

So I don't understand how the ABX test could prevent people to hear
differences that they claim to hear in other conditions. I won't claim
that any one in this forum is not hearing was he says he is, but I claim
that under proper ABX double blind test, he should hear the difference.

Fabrice

[NealG]

But for me that's the problem IMHO Fabrice, "....under proper ABX double blind test, he should hear the difference."

What is 'proper'? As Andrew pointed out it's not a natural way to listen, it creates a false environment. I struggle to understand how we can apply a scientific test to what is a purely subjective and emotional event. No two people perceive visual or audible stimuli in the same way, yes, the sound may be the same reaching the ear but the listener’s perception of it will be different. I also feel that there will be a level of pressure on the listener to identify a difference. Does that not happen with wine tasting? Two people may recognize the taste of the same wine and recognize/identify it correctly but do they actually perceive exactly the same flavor?

Should we also say ‘better’ instead of ‘difference’? Hmmmm, maybe not as it’s a test but there again it’s a personal and emotional event to which I can’t help thinking you can’t apply such stringent rules………

Setting up of such tests would also be a nightmare, getting levels and balance correct for instance would take great care.

What I meant by 'risk' earlier is with taking 'snapshots' or 'samples'in time of a listening experience when the measuring tool IE: the listner is not at his or her receptive 'best'. The worse case would be that at each 'sample' the listner percieved the least or 'worst' result. Averaging the test out over several days may well eliminate this but aren't we back with subjective long term listening in this case?

Anyhow a good discussion that I am learning from.

[Fabrice Rossi]

NealG a écrit :
> But for me that's the problem IMHO Fabrice, "....under proper ABX double
> blind test, he should hear the difference."
>
> What is 'proper'? As Andrew pointed out it's not a natural way to
> listen, it creates a false environment. I struggle to understand how
> we can apply a scientific test to what is a purely subjective and
> emotional event. No two people perceive visual or audible stimuli in
> the same way, yes, the sound may be the same reaching the ear but the
> listener’s perception of it will be different. I also feel that there
> will be a level of pressure on the listener to identify a difference.

Difficult question. I in fact don't know if reasonable experimental
settings (on a scientific point of view) will be accepted by many
audiophiles. I suggest to give the listener the device A for a long time
(let's say a week) and the same thing for device B (both with complete
identification). And then, we just remove all identification means and
ask for the listener which one he prefers, or which is which. He/she can
listen as long as he/she wants. A bit theoretical, isn't it?

> Does that not happen with wine tasting? Two people may recognize the
> taste of the same wine and recognize/identify it correctly but do they
> actually perceive exactly the same flavor?

Indeed. I guess this is because we don't have correct words to describe
the actual taste and smell of a wine. It's very frustrating in the
beginning when you're told that this wine smells chocolate and you only
smell alcohol. With some training, you can identify some specific
flavors and odors, but I think no one perceive a wine the same way.
However, this does not prevent recognition and quality judgments.

> Should we also say ‘better’ instead of ‘difference’? Hmmmm, maybe not
> as it’s a test but there again it’s a personal and emotional event to
> which I can’t help thinking you can’t apply such stringent rules………

I would stay to difference rather than better. If you listen to rock
music for instance, I don't think you can say more than "this way of
reproducing the sound suits me better than this other way", because
there is no such thing as a natural sound when you are listening to an
electric guitar. Of course, with jazz or classical music, this is
another story and there are in way some references (live performances).
I'm always puzzled by some people who claim that this sound device
sounds very natural but never listen to jazz or classical music, or have
never attended to a live performance. But even so, difference is more
neutral.

> Setting up of such tests would also be a nightmare, getting levels and
> balance correct for instance would take great care.

Absolutely. But in some situations its easy. For instance, if you have 3
SB2, you can easily set up an ABX test for a fancy PSU (you need two of
those ones). On the other hand, implementing an ABX test for
loudspeakers seems more difficult.

> What I meant by 'risk' earlier is with taking 'snapshots' or
> 'samples'in time of a listening experience when the measuring tool IE:
> the listner is not at his or her receptive 'best'. The worse case would
> be that at each 'sample' the listner percieved the least or 'worst'
> result. Averaging the test out over several days may well eliminate
> this but aren't we back with subjective long term listening in this
> case?

Yes we are. But even so, it think you might figure out something in this
kind of setting (long term hearing test) as long as every thing stays
double blind.

> Anyhow a good discussion that I am learning from.

Me too. I especially enjoyed the discussion about short term memory vs
long term because this was really something new for me and its very
convincing. But all the discussion was very interesting.

Fabrice

[Mike Hanson]

You might like to investigate Andy Weekes' Super Regulator (ALWSR).

I've been in frequent contact with Andrew, and he's been exceedingly helpful in guiding me along the path to power supply nirvanah. I don't expect my designs to rival his, but for now I'm having fun playing with him. In the end, I'll probably get some of his units, just to see what I can see.

-=> Mike Hanson <=-