Re: One for the bottleheads

In article <drod68$ied$1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Rob
<removethispatchoulian@xxxxxxxxx> wrote:
> Jim Lesurf wrote:

> > 
> >>As for the science that underpins the objectivity claim, I would
> >>simply state that you only know what you know today, and some other
> >>explanation of variation and experience may arise tomorrow. 
> > 
> > 
> > That is reasonable as a general statement. However it does not mean
> > that "we do not know everything" is a synonym for "we know nothing". 
> > :-)
> >

> We may know all there is to know - frightening thought.

But not one based on a statement that I make above.  :-)

> > It is clearly open to people to speculate without any real evidence if
> > they so wish. However the 'objective' definition I gave for 'accurate'
> > as a term for an amplifier is one which can be applied, and the
> > results determined.
> >

> Results are *interpreted*, not determined. 

No. The experimental process determines results (evidence). We may then
interpret these in terms of assessing hypotheses.

[snip]


> > 
> >>My main point is the validity - the *importance* - of such a finding
> >>(sound in equals sound out, only amplified). 
> > 
> > 
> > You are now talking about the value judgements you wish to make on the
> > basis of any findings. That is fine. However we need to distinguish
> > your personal judgements from the objective definition, and the
> > evidence returned by measurements of the accuracy of an amplifier
> > according to such a definition.
> > 

> I'd simply have to say that any result that comes from a measurement
> that is 100% replicable (were such a thing possible) is open firstly to
> context, and secondly to interpretation. 'One Volt' is fairly
> insignifcant in some contexts, all important in others.

Your phrasing above is rather odd. Results are not "open to context". They
will depend on the context, and should be interpreted with the context in
mind.

[snip]



> > In principle, provided we avoid many-to-one mappings, we could counter
> > one nonlinearity with another to get a total result which was more
> > linear. The snags, however, are as follows:
> > 
> > 1) We may have no idea what 'nonlinearities' we are trying to null or
> > cancel.
> > 
> > 2) Any such nonlinearities may vary in an unknown manner from each
> > bradcasting or recording to the next.
> > 
> > Hence the idea that one 'amplifier' could 'null' these in a systematic
> > manner seems rather dubious.
> >

> But it's still interesting how some people report, yet cannot prove,
> seemingly impossible difference don't you think?

The snag isn't that they "cannot prove" this since the scientific method is
not about "proving" something. The snag is that they seem unable to provide
any reliable evidence that reliably bears on their claims, or provide an
experimental method we can use to discriminate their hypothesis from
alternatives.

The main problem being that they make the claims, but then refuse to
enagage in any test that seeks to determine if they can actually tell
solely on the basis of the sounds produced. Thus we are unable to collect
evidence which might either support or conflict with their claims.

[snip]

> > 
> >>>Secondly, your assessment of 'accuracy' is entirely a matter of
> >>>personal judgement based on no actual measurements.
> >>>
> > 
> > 
> >>Precisely - but I question the validity of measurements. You (I think)
> >>rest your case on their unassailable objectivity.
> > 
> > 
> > My case is that they are defined and can produce evidence we can
> > evaluate.
> > 
> > It is up to you, and each of us, to decide for ourselves what value
> > judgements to make of the results.  :-)
> > 

> Wasn't it your point that results cannot be interpreted - they are
> simply read as fact?

No. My point was what I was explaining.  :-)  In the specific example, that
'accuracy' can be defined in a specific objective way that allows it to be
measurable and assessible. In effect, you measure and compare the input and
output waveforms and see how similar they are when you allow for a scaling
factor and a delay. In the context of an amplifier this seems an entirely
appropriate definition for 'accurate' since an amplifier is supposed to
'amplify' (i.e. scale up or down the signal patterns) and a small delay
does not really matter in this context.

However what use you put this result to is another matter. If someone does
not want 'accuracy' then such a result is of little interest to them.

> > 
> > 
> >>I don't see how the statement is ambiguous. We can agree that the
> >>listening experience is relative and subjective, probably. We disagree
> >>that the measurement of electrical equipment is *always* relative and
> >>subjective.
> > 
> > 
> > Yes. If I inject a signal of 1mV and the output is 1V Then I would say
> > that the voltage gain under the conditions of the test is x 1000
> > within the limits of the accuracy of the measurement. Can you say how
> > this is a "subjective" statement? I can also see that the voltage
> > measurements were relative to the definition of 'the Volt', and that
> > the gain value is a ratio so 'output relative to input'. Is that what
> > you mean?
> >

> But isn't a volt an ambiguous unit? I don't follow you there - too
> technical :-)

In what way do you think 1 Volt is an "ambiguous unit"? It is one of the
basic units defined for measurement purposes according to international
agreements. These days IIRC people like the NPL define the Volt in terms of
the quantum Hall effect, so linking it to a fundamental quantised property.

Slainte,

Jim

-- 
Electronics  http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Audio Misc  http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio  http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html
.

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