The suggestion that cables should make up 10% of the system cost clearly came from a cable company.....
I think it is upto 10%, not 10%.
There does seem to be a common figure. Check out 'Chapter 4' http://www.whathifi.com/video/get-the-best-from-your-hi-fi
The 10% thing seems to have become semi-institutionalized. When I bought an amp and DAC several months ago, the retailer was doing an offer: free interconnects up to the value of 10% of your spend on other kit. Needless to say, I took them up on the offer, though it might have been fun to say "You can keep your fancy interconnects, they don't make any difference!", just to see the look on their faces. (Of course, I did try the 'I'd rather have some money off the amp and DAC" line, but Head Office wouldn't have it.)
Probably because the mark up on cables is much higher than the actual gear.
In other words, not only is the SQ benefit dubious, the stuff is also being overpriced.
What classical music are you listening to?
On the subject of testing components in a system - expectation bias is very difficult to overcome, blind testing is a solution but is awkward and requires assistance.
What I would recommend as a simple alternative is A-B-A testing, ie: Listen to your system, swap in new component and listen again but then go back to the original and listen again. It's quite an effective and quick way of gauging how real a difference may be. Often when making a change you hear a "definite improvement" initially but when you swap back it's less obvious in hindsight. It doesn't completely get around expectation bias but it is far better than a simple single swap for new component. Also use a track you know well and listen for a short period, you know quite quickly if something is right or not. When happy with your system you can always have a longer listen with more material.
The difficult thing with psychoacoustics and expectation bias is that if you think a component is better for whatever reason, even if technically it can make no difference, then in a very real way it IS better for YOU - you will hear the improvement! People will argue that there is technically no difference and may well be correct, but if you believe there to improvement then that improvement will be real to you. It's the reason there are so many ongoing debates on Hi-Fi forums about cables etc and it's an impossible battle to win either way because both camps are right in their own way.
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My view is I can accept the theory that different cables affect (analogue) sound, but what I can't see is the correlation between a cable's SQ and price. Or put it another way, what is it about the construction of expensive cables which we're lead to believe makes them sound better? Or put it even another way, what is it about good-sounding cables which we're lead to believe makes them expensive to manufacture?
I can look at an expensive hand-built turntable, I can see and feel the quality of the build and workmanship, I understand why that quality of build costs money, and then I understand the basics of why that high-quality solid build potentially has a positive affect on the tt's SQ. But not so a cable. I can't see what's in a brilliant-sounding cable which makes it more expensive to manufacture than a cheap one.
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The API guide linked in Matt49's thread gives an excellent explanation of how (speaker) cables can and do measure differently and more importantly how different amplifier and speaker characteristics affect the cables performance. Some of the HF roll off in some of the samples were pretty shocking.
Sadly it is beyond the brief of the paper to investigate how these changes relate to what is actually heard but I think the real lesson here is how the cable interacts with the components on either end.
Speaker cables (in this case) are clearly system dependent, something that was obvious enough in my time as a dealer, but rarely analysed.
AEJim's suggestion of A - B - A testing is sensible enough and many of us (more anal types) have been doing it for years but even so it really no substitute for blind testing.
I strongly urge any enthusiast to take part in a blind test if given the chance. If nothing else it will give you a really good handle on how small differences in suposedly very different components can be.
We do so many shows in a row,
And these towns all look the same,
We just pass the time in our hotel room
And wander 'round backstage,
Till the lights come up, and we hear that crowd,
And we remember why we came.
Yes I agree with AEJim and have suggested something similar, I have read several reports along the lines of changing the cable to a more expensive and it sounded better, then doing the same again with a more expensive one and so on but then returning to the original and he could not hear any difference. Maybe on the first the amp was just warming up or his brain was. I agree blind testing is better if you can arrange. Sometimes people can hear a difference but they don't believe the difference is worth the extra cost, sometimes the more expensive cables sound worse.
Sadly it is beyond the brief of the paper to investigate how these changes relate to what is actually heard
For that you'd need a psychologist ...
You will need a statician too, the EDITEDs get in everywhere........
But the psychologist will have been trained in statistics, so you won't need the EDITED statistician.
I just going to keep asking until someone give a satisfactory answer - What proof is there that double blind ABX testing works for audio?
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ON THE HOOF: iPhone 5S/Sennheiser MM450.
It depends what you mean by "works".
The ABX testing that's been done on hifi kit has in most cases produced statistically null results, i.e. the subjects in the tests have displayed preferences (e.g for an expensive amp as against a cheap amp) that are statistically no different from complete randomization.
But (and davedotco may disagree here) this ABX testing has not been carried out to standards that those in the field of psychoacoustics would regard as academically robust.
Also there are vanishingly few hifi "experts" who are willing to submit themselves to these trials, for a variety of reasons.
The conclusion I draw from this is that the jury is still out and is likely to be out for a long time yet.
That may or may not be a satisfactory answer.
Double blind and ABX testing are two different techniques, i believe they are quite different in psycological terms, thogh matt49 will put us straight on that.
In both cases the test equipment is set up in such a way that all variables are excluded, apart from the the items being compared, ie in the case of an amplifier test the tone controls would be set flat, the output levels carefully matched and care taken that both amplifiers are working well within their designed capabilities.
In a double blind test the test subjects are played excerts of music on one system, then on the other. They are simply required to say which one they think sounds best. Importantly, the person carying out the test does not know which amplifier is which at any point.
An ABX test is subtly different, in this case music is played on one system then the other, then a third time on either the first or the second system. The subject as asked whether the third sample is a repeat of the first or the second sample.
This is repeated as often as possible, with as many subjects as possible and the results calculated statistically, but I believe differently in the two cases.
There are also variations on these tests where tests are inserted where the two excerts are played on the same system. ie there should be no difference, and the results of these tests analysed too. All of these results can be (and have been) subjected to rigorous statistical analysis.
All of this analysis is of interest to academics but the ordinary hifi enthusiast simply wants to know whether he can tell a difference or not and the answer is often not.
Perhaps more importantly the enthusiast gets to see just how tiny the differences can be between, apparently, quite different products.
That's an invitation if ever I saw one, but I fear I would bore everyone (if I haven't already). Well, OK then, just a quickie.
All serious testing is double blind. Double blind simply means that both the subjects of the test and the people conducting it are ignorant as to the identity of the things being tested. This is so that the people conducting the test can't convey any subliminal cues to the subjects.
ABX testing is one of a large number of (double blind) sensory evaluation test protocols. Davedotco has described it well above. There's a brief and accessible description of various test protocols in Meilgaard, Carr, and Civille: Sensory Evaluation Techniques, pp. 59-98. Sensory evaluation tests are big business in e.g. the food and cosmetics industries. Their methodologies and results are controversial. AFAIK no serious studies have been done on sensory evaluation techniques for hi-fi.
What I find so curious is that they get mentioned as being absolutely foolproof. I see two problems: firstly, reliance on short-term memory. We can assume instant switching so no delay but what evidence is there that that we can actually remember enough to draw any conclusions? Audio introduces some particular problems. For instance if we want to compare the quality of two different photographic lenses we could print out the results from each & examine both side by side, looking for particular aspects such as sharpness or colour fringing at both the centre & around the edges - we can scan with our eyes, notice aspects, recheck etc. We are not constrained to only look at one or the other in sequential time frames.
With audio, we have to listen, then memorise then listen again - so what are we testing - audio memory or potential differences? Any differences noted are totally reliant on memory - if testing amplifiers, no one is suggesting we level match with one playing through the left an the other through the right speaker simultaneously! Am I alone in wondering whether or not short-term memory is better than longer-term memory? I ask because I find I get very confused with short quick-fire tests! I also often notice differences in perceived SQ after months not seconds. This may occur after playing a particular piece where I notice additional details. If I’m not listening out for differences & am just enjoying music, Expectation Bias is surely not an issue. Short-term memory maybe very convenient for formal DB ABX testers but only if effective!
So just how we confirm short-term audio memory is useful or not? ABX is very effective at filtering out false positives by the very nature of its statistical analysis but surely any methodology should be good at weeding out false negatives?
Let’s assume for illustration that we have room full of sceptics who firmly believe that nearly all differences with amplifiers are imagined. So they either genuinely cannot tell or have an axe to grind or just plain old Expectation bias plays its part! Once this particular group's responses have been analysed the numbers are close to 50 when averaged. This result would be similar to a random result. If a similar test was carried out on (for the sake of argument) a group who could tell the differences between amplifiers under test, the average result would be higher than random where the greater the number, the more statistically significant would be the results. As far as I know, most such tests "prove" no differences can be heard & the statistics are the same as being random. OK so far - still with me? Do you see a flaw to this like I do?
How do we differentiate between there being no detectable differences because none exist or the possible fact that the test method is flawed & that no subjects can tell anything whether or not they are real. What I'm saying is that a group of near deaf people could take the test & the result would be random unless we can filter out the potential false negatives. Their results would hover around 50 but never be lower. Unless I'm failing to understand the methodology of such testing we need to have some sort of control during the test such as real repeatable & deliberately introduced differences. These could be left right level imbalances, added distortion etc. The purpose of these controls is to highlight the deaf or axe grinders so no one can skew the results therefore making the results either less valid of highlighting the flaws of the methoditself. The level of these deliberately introduced controls could be incrementally increased to the point where they should be obvious. If they can't, be heard, what hope is there that the rather subtle variations in equipment can be heard? Without these controls, I fail to understand how anyone can think the tests work. If we sort out the potential false negative problem, we also get a handle on whether or not ABX tests prove anything. I'm sorry this is very long-winded but I can think of a simpler way of explaining it!
Last time you asked the same question I linked to a number of ABX tests which had been passed (eg for speakers). So that rather disproves your notion that a segment of people deliberately always fail them.
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