janneman said:
I disagree, Jan.
The loudness effect you refer to is highly system and room dependent.
Actually I find quite the opposite effect (within SPL reason...).
When you get loud enough (some threshold) the room overloads, reverberation levels become too high (for most rooms), and then ears overload too.
The only time I have ever heard louder & louder sound correlate to a wider and more spacious soundstage is with the rare system in the rare room where the system is ultra ultra ultra capable of highish SPLs without the usual attendant increase in distortions, AND the room does not overload (usually a large room with longer than average reverberation times anyhow).
Actually, there is a narrow range for most rooms where the SPL correlates to the best listening experience, above and below that range, things degrade - of course there may be exceptions, but not too many. Also a whole lot of what the real world range literally depends on your environment's background and foreground noise levels, including super and subsonic.
Most folks who do not live miles away from civilization have various sources of sounds that they simply loose touch with and don't notice their existence at all, but they effect the listening experience none-the-less.
_-_-bearf
janneman said:
I don't find that volume differences within a reasonable range affect the soundstage size or instrument positions. I believe in a reflective room it will have an effect however I don't like many reflections, I want to hear the original sound as much as possible with a minimum of added reflections.
I've also found that with some amplifiers, (in a room with curtains and absorption all around) the soundstage is confined between and behind the speakers while other can create a defined soundstage far wider than the speaker position extending from in front of the speakers to far behind them. Both not dependant on volume levels.
SY said:
In this case the sonic defect was the amplifier, no further need for measurements.
SY, you are still missing the point I'm trying to make, I believe we lose low level detail in all equipment, some only more than other. What measurement will show this? Dynamic range yes but I believe there are more to it.
janneman said:
It's probably a compromise between ideal testing and practical duration. I have read about DBT's where the subjects were given the control and they could switch as often and listen as long (within reason of course) as they wanted.
What is a practical limit? In my experience, I hear differences (real or imagined
Jan Didden
Edit: What about the ABX test? You, as the listener, have a switch and you can listen to amp A, amp B, or amp X, where X is either A or B, but you don't know (nobody knows, even not the test director, and this is critical).
Your task is to identify whether X is A or B. Of course X is changed random everytime you select it.
I don't think it can get simpler than that. You can switch whenever you want, to A, B or X whatever you want. You can play the music you want, for as long or as short as you want.
If you cannot correctly identify whether X is A or B, in a statistically significant number of trials, I'm willing to accept that there is no audible difference between A and B.
(Let's for the sake of discussion assume that the test box itself doesnot mask the difference. It is a valid issue, but let's just concentrate on the concept here. One step at the time).
Jan Didden
stinius said:
I don't feel anybody here is spoiling anybodies time. As to the Thermal Trak, I've been using the Sanken STD03 series thermal track darlingtons for the last few years with good results. The diodes on those are monolytic and therefor have much less issues than the Toshiba's, so for me there is no problem. But I follow that thread with interest, there's a lot of smart people doing smart things there. I'm learning a lot.
Jan Didden
janneman said:
Jan, I don't have a problem with that idea, my only concern is that when you are trying to listen for smaller differences, there are other factors at play also.
A few of them:
1) On an unknown system it is much harder to hear differences, I prefer my own.
2) The system must be able to reproduce the differences that are expected to be there. Who decide what system must be used?
3) The listeners can not be randomly selected, you can not expect a grandma to evaluate a sportscar.
4) Any stereo system has only one correct listening position, therefore only one can do the test at a time.
5) Blind testing can be very fatiguing.
6) Some concentrate more on the test than on listening.
There must be more but it should be a good start.
Andre Visser said:
Yes, all good points, and all must be taken care of as good as possible. But they are not impossible to overcome. And even if you can't get it 100% as you would like, what is the alternative?
An unknown person with an unknown system with unknown interests stating that he 'clearly heard that cable A has much more details than cable B'.
Serious investigation and research never is 100% perfect, but I'll take some reasonable form of blind test over the anecdotes anytime.
To be sure, this has nothing to do with personal preference. If you like cable A better than cable B, by all means. But that's *your* personal perception and *your* personal preference, which is perfectly valid for you. But it doesn't say anything about any differences or not between A or B in *sound* alone.
Edit: indeed blind testing is more fatiqueing than casual listening. The brain is deprived of a lot of cues and has only the sound to work on, and must work harder.
At the last AES there was a workshop on listening fatique in general, but the main conclusion was that there is very little study done on it and reports partially contradict themselves. However, there seemed some kind of consensus that listeners that are asked to evaluate something (whether blind or sighted)report listening fatique after about 20 minutes, but that the results already start to show errors due to listening fatique after 5 minutes (although the listeners are not aware of it until the 20 minutes).
Jan Didden
janneman said:
It's probably a compromise between ideal testing and practical duration. I have read about DBT's where the subjects were given the control and they could switch as often and listen as long (within reason of course) as they wanted.
What is a practical limit? In my experience, I hear differences (real or imagined
Jan Didden
Differences between various parts of the system, be it cable or amplifiers or anything else, are noted within few seconds, or few minutes. However, which one is more enjoyable may take prolonged listening. So, both seem to be necessary.
janneman said:
Different people here have different aims. Some aim at scientific study, applicable to all people, or to people in general, while others aim at pleasing better their personal listening experience.
My aim is the second, pleasing better my personal listening experience. In this, choosing cable A over B is definitely a matter of personal taste and preference. However, it cannot be concluded that my preferences are over non-existing sound differences. The mere fact that the preference is personal is not any proof that the differences are imagined.
janneman said:
... and of course the preference for which is more enjoyable may be different for different listeners. Otherwise we would all buy the same amp
Jan Didden
Of course. That goes without saying, or, at least, it should be obvious.
However, when personal preferences are there, there is so much one can go with purely scientific methods.
Indeed, when I choose a cable, or amplifier, or whatever, to my system, I conduct blind tests. The blind tests are aimed at locating the actual sound differences, versus possible imagined ones. However, when I prefer the sound of cable A over cable B, hooked to my sound system, I cannot possibly say that cable A is better than cable B in general, for all people, and/or on all systems.
Furthermore, some people prefer some coloration or imbalance to their sound systems. Others, me included, prefer the system to be as transparent as possible. Which is why stating that amplifier A is better than amplifier B, as a general statement, is meaningless.
janneman said:
For sure they are not impossible to overcome.
I agree but when more than one describe the same differences, then it get interesting.
Very interesting.
I've done a blind test on cable direction
a while ago and quitted the test after 9 tries, not sure if I want to do that ever again. janneman said:
I´m terrible sorry janneman, but your´re not right in this point.
This sort of test is called ´forced choice test´ and is well established in sensory tests.
A test with two possible answers `a better than b´and ´b better than a´ is called a 2-AFC-test (two alternate forced choice), if you do such a test with a group of listeners listening at the same time, it can be better to include a third choice `no difference´to avoid rumors in the panel from listeners hearing no differences. That would be a 3-AFC-test.
Wishes
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