Why on earth do speaker wires sound different?

[Nevalti]

In the real world we can tell with amazing accuracy where in space a sound comes from.

What evidence do you have for this? I think you only think you can do this.

That of my own ears and experience.

Imagine you are walking alone in some dark woods. You are a bit nervous because humans still have their primeval prey instinct in that situation. You hear a sudden strange noise and you KNOW, without any doubt, that it is about 6 ft away from you, behind you, about 45 degrees to the right and about 1 ft above your head height. Most of us would be able to swing round and point our torch directly at the source of that noise without any hesitation. We have located the direction, distance and height of the sound just(?) with our two ears. How? My point was that you could not reproduce that 'information' with a dummy head and a pair of headphones. All you would know from the head-phones is that the sound was somewhere to the right.

[Dave2002]

That of my own ears and experience.

Maybe, but you are probably wrong!

[Nevalti]

This sounds a little speculative.

That is precisely why I said 'possibly'. Consider the recent 'discovery' that the full moon affects our sleep. Most of us would have put good money on the scientific study of the subject finding that the scientists were right - it was just a myth. However, as you probably know, they have recently proved that the moon does actually affect sleep. Whatever the reason is, who would have thought of measuring it or how to measure it? It is a very bold person who thinks he knows everything or relies on theory instead of experience because we will never reach a state of perfect understanding. Presumably, in this instance, the factors are minute differences in gravity and/or minute differences in light seeping through the night sky and our curtains. Whatever it is, it SHOULD be salutary that our ancient ancestors understood this better than we do.

[Phileas]

It is a very bold person who thinks he knows everything or relies on theory instead of experience because we will never reach a state of perfect understanding.

Hence the need for properly controlled, level matched, double-blind ABX testing.

[Dave2002]

... they have recently proved that the moon does actually affect sleep.

Again, no! They have apparently established a correlation in the state of the moon and human sleep, but that's not necessarily a causative relation. Not a proof.

[Nevalti]

.......t it's a bit like trying to hear a bat fart at a thousand yards (he said, avoiding the hugh moral ground).

Off at a bit of a tangent - I can hear the bats near my house up to about 100yds away or thereabouts. Some people apparently can't hear them at all and tell me I am imagining things - until I shine a torch precisely at the (flying) bat in question.

Before anyone asks, yes, my friend Robin can hear them too.

[Nevalti]

Again, no! They have apparently established a correlation in the state of the moon and human sleep, but that's not necessarily a causative relation. Not a proof.

I feel that you are clutching at straws there Dave. There is a 'cause'. Who thought of measuring 'it' and what is 'it'?

[Nevalti]

Maybe, but you are probably wrong!

Why 'probably'? What about the dark woodland example? Unless your hearing is impaired, I have no doubt you could point a torch at the source of a noise - in any 3D direction - just as the rest of us could.

Because of where I live, I often have to walk around in the dark and I have often done exactly what I described earlier, even if it was just a tiny froglet hopping or a beetle moving a dry leaf.

At its simplest, we all know, no doubt whatsoever, whether a noise comes from behind us or in front of us. The dummy head and head-phones can't even tell us that basic information let alone the precise 3D information that I described.

[An_Inspector_Calls]

At its simplest, we all know, no doubt whatsoever, whether a noise comes from behind us or in front of us. The dummy head and head-phones can't even tell us that basic information let alone the precise 3D information that I described.

Strange, then, that the subject has been studied, and explained, in such detail:

http://en.wikipedia.org/wiki/Sound_localization

So if they can analyse this phenomenon, can't they explain why people (apparently) can tell the difference between different connectors?

[Nevalti]

Hence the need for properly controlled, level matched, double-blind ABX testing.

I would be very interested to take part in such a test to see exactly how they are conducted. When I audition equipment I may well use a dozen different CD's that I think I know well in order to explore the performance of many different aspects of the equipment. Some middling sounds seem to be pretty easy to reproduce and there may be little obvious difference between the equipment under test. Other recorded sounds are far more taxing and telling. It is no good trying to hear how well dynamics are reproduced unless there are some realistic dynamics to listen to. The sort of thing I want to know is what happens to that nicely detailed sound when the amplifier (etc) is suddenly asked to go much louder and add in some more taxing instruments? Do the quieter, delicate sounds get swamped so that you can't even hear them? All too often that is the case. Similarly, you can't compare performance at any of the extremes, unless there is recorded information to test them with. It goes way beyond that of course and what is important to me may not be important to someone else. I have difficulty therefore understanding how a meaningful test panel can be assembled.

The worst flaw of all in AB testing is that they are 'level matched' - as if that was a good thing! What happens when you turn the volume up or down? What happens when you use different speakers etc, etc. For example, the Musical Fidelity M6-500 is one of the best amplifiers I have ever heard (with my speakers) BUT only at one level. If you drop the volume below that 'sweet-spot' level the tonal balance (with my speakers) changes and fine detail reduces so that it simply sounds wrong. Conversely the excellent ATC P1 amplifier retains precisely the same tonal balance and detail (with my speakers) right across its volume range BUT it is incapable of providing the realistic dynamics and control that the M6-500 can (with my speakers) when the music gets loud and complex. Level matched ABX testing of those two amplifiers would prove what? Seriously, what would it prove? Which would be judged to be 'better'? Would you really buy on the basis of a 'level matched' ABX test? NO, surely no sensible music lover would - would they? All audio equipment is flawed, perfection does not exist. Choosing what to buy is mainly a matter of deciding which flaws and drawbacks you are willing to accept. Once you have heard top-notch equipment, that has significantly fewer flaws, you are in a much better position to decide what flaws you are willing to accept. It is rather like viewing an HD TV but deciding that you are quite happy with your SD TV - which some people are. If someone deliberately avoids listening to to-notch equipment, they will never know what they are missing. Most people I know have never, truly NEVER, heard a really high quality hifi system; perhaps they are lucky.

It seems to me that there is no substitute for comparing real live sound with the reproduced music. 'Pop' music, as has been said, is useless for auditioning purposes unless you know what the live performance was like. With live classical music or perhaps 'unplugged' music, we have a wealth of experience to draw upon which tells us what a real live guitar, cello, female voice, orchestra etc is likely to sound like. For example, we are likely to 'know' how well the plucked cellos stand out in a particular passage and, if they don't in the reproduction, we 'know' something is wrong. Without that grounding in what something really sounds like, AB testing becomes a pointless exercise of identifying a vague preference. That does not strike me as very useful.

[MrGongGong]

At its simplest, we all know, no doubt whatsoever, whether a noise comes from behind us or in front of us. The dummy head and head-phones can't even tell us that basic information let alone the precise 3D information that I described.

Are you sure about that ?
People I have met who do Binaural , Ambiasonic and other multi channel format diffusion etc would probably say something else.
Have you listened to binaural (adjusted ) recordings ?
I suggest having a look at this

http://www.dallassimpson.com/

who knows more about this than anyone I have ever met

Also , image a phase and perception are regular topics for discussion on the CEC list
maybe have a look there as there are many rather clever folks who have studied this in depth

[Nevalti]

Strange, then, that the subject has been studied, and explained, in such detail:
http://en.wikipedia.org/wiki/Sound_localization...

Thank you for that link AIC, it makes the points I was making very well indeed. It was stated earlier, by someone else, that a dummy head and a pair of headphones can replicate virtually 'everything' that we can hear in real life. I challenged that notion and this article explains why they can not. It also explains why one can not measure 'everything'.

(Why you say 'strange, then' is a mystery to me. Perhaps you mixed up my post with someone else's.)


Mr GG. I suggest you read this article.

[An_Inspector_Calls]

Because in your previous statement you had 'we know we can localize sounds in three dimensions' but by saying dummy heads can't even measure this phenomenon ("The dummy head and head-phones can't even tell us that basic information let alone the precise 3D information that I described.") you implied that this can't be measured. In fact, the basis for the phenomenon seems very well measured and understood.

[MrGongGong]

In fact, the basis for the phenomenon seems very well measured and understood.

And is discussed endlessly on electroacoustic music forums

[Nevalti]

Because in your previous statement you had 'we know we can localize sounds in three dimensions' but by saying dummy heads can't even measure this phenomenon ("The dummy head and head-phones can't even tell us that basic information let alone the precise 3D information that I described.") you implied that this can't be measured. In fact, the basis for the phenomenon seems very well measured and understood.

I would say, 'fairly well understood' and 'measured to some degree'. My statement was that a dummy head and head-phones can't even tell us that [front or back] basic information let alone precise 3D information. Can we be perfectly clear - are you saying that a dummy head and headphones CAN give you precise 3D information?

If you are going to say 'yes' how does it replicate all the other cues described in your Wikipedia article when no steps were taken to gather that information? Just one obvious example.... the asymmetric ear positions needed to provide height cues - an asymmetry that will be different in each of us.

It must be theoretically possible to measure some individual and then produce a dummy head recording that provided that single person with precise 3D 'imaging' - but I doubt it could be achieved very successfully; there are still too many variables and too much 'everything' that the head-phones will not provide. That gets back to my point, I was challenging the suggestion, made by someone else, that a dummy head and headphones provide "virtually 'everything' we hear". You have already, quite rightly, demonstrated that they do not.

Believing that we can measure everything we can hear is rather like believing that we can measure everything that we can taste or smell. We can measure a lot of it and replicate a lot of it but try making a chemical facsimile of some good wine and see what the wine buffs make of it! Try masking a smell so that a dog can no longer detect the original smell. I am saying that the same sort of things apply to sound. 'We' understand a lot of the problems but far from all of them. If we could replicate an original sound accurately there would be no place for the plethora of competing sound reproduction equipment that there is. At the moment, all manufacturers and designers are striving and compromising; perfection is getting closer but I doubt we will ever get there.