Richard Burwen told me that when he is critically listening, and he picks up his whisky tumbler to take a sip, and places it back in a different spot than it was before, he can hear a sound difference.
If that is the case, it underscores the stringent conditions for a good test.
Jan
In the article that John Curl provided a few pages ago, , one of the blind tests was conducted by 3 people, the author, his wife and P. Crook. 😀 😀
How about that ?
Hans
How about that ?
Hans
Not so surprising, isn't it Earl Geddes says diffraction is one of the biggest issues in acoustics?
Listening position variation can be mitigated by using quick (within fraction of a second) switch method between DUT. Not stringent at all.
So, a mind-altering substance makes a difference in perception?
Isn't that WHY we drink?
That´s the point.
Don´t think glass position was as important as glass contents reduction.
On a more serious point, very much doubt his head returned to exact same position and angle, and *that* is way more important, whisky or not.
Don´t think glass position was as important as glass contents reduction.
On a more serious point, very much doubt his head returned to exact same position and angle, and *that* is way more important, whisky or not.
It's probably better to use headphones whenever possible? What would be the best way to test speakers, double blind rapid ABX seems impractical?
You have two setups behind a thin black curtain, with the relative positions of A and B chosen at random. Rinse, repeat (yes you don't get rapid changeover, but you can AB switch as you want for each configuration). Its tricky to match volume levels fairly too as polar patterns differ, and typically a louder configuration gets voted as "better".
Its also an issue with the noises made by changeover, so you need a way to prevent the subject being able to sense these.
If the subject(s) can consistently track the changeovers you know the difference is audible, and their preference for the sound is blinded.
However if the speakers are very different and the choices known its still possible for the subject to know which is which from bass-extension or vertical positioning etc.
Its also an issue with the noises made by changeover, so you need a way to prevent the subject being able to sense these.
If the subject(s) can consistently track the changeovers you know the difference is audible, and their preference for the sound is blinded.
However if the speakers are very different and the choices known its still possible for the subject to know which is which from bass-extension or vertical positioning etc.
To make sure tested speakers are always at the exact same position, Harman build the 'speaker shuffler', a pneumatically powered system to move speakers around in always the same position. I believe it cost less than a million bucks.
Jan
Jan
The very fast OPA1656 has to be used with great care, meaning good power supply decoupling, preferably a ground plane and a well designed PCB around the input connections.
Despite the low source resistance driving the preamp, the interconnect’s capacitance and switchable input resistors can easily lead to stability problems causing differences in sound perceptions.
Proof of the pudding would be to try a slower opamp that’s less critical like the OPA2134 or the OPA1642 and see if the supposed sound differences are still there.
I bet they won’t.
Hans
Despite the low source resistance driving the preamp, the interconnect’s capacitance and switchable input resistors can easily lead to stability problems causing differences in sound perceptions.
Proof of the pudding would be to try a slower opamp that’s less critical like the OPA2134 or the OPA1642 and see if the supposed sound differences are still there.
I bet they won’t.
Hans
Back in the day I did a lot of mono listening, i.e. 1 speaker. Often against a reference placed next to it symmetrically in the room so room modes were equally excited. Often using live environment sounds, i.e. a measurement mic placed outdoors. IMO recorded music is not always the best source material for evaluating things.
Nowadays I prefer headphones. Eliminate the room entirely.
'Should be' is an interesting choice of words. So is, 'golden ears.'
Seems like most people in these threads have decided what they want to believe a long time ago.
When someone can hear the brownian motion of air in a room at STP then they might start worrying about things 130dB down. For everyone else I think the phrase 'below golden ears resolution' makes a lot of sense. Clearly rediculous claims of audibility remain just that.
Here's a scenario: a trained subject is listening in a supa-dupa system quite loud. The sound pressure makes the mains power cables vibrate within a few tenth of micro inch. Due to the EM field laws, that movement induces an EMF in these power cables. The EMF makes it back through the amplifier power supply to the signal chain. It's clearly audio signal correlated.
I am sure a trained subject can hear that too. It's a good experiment to promote and sell high end audio power cables at $1000 a foot.
I am sure a trained subject can hear that too. It's a good experiment to promote and sell high end audio power cables at $1000 a foot.
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If you are playing loud enough pretty sure the rarefaction will affect it. Air is a compressible fluid after all.
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