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In Reply to: RE: Have you listened? posted by JLindborg on November 02, 2014 at 01:52:16
Can you speculate successfully if data points are invalid? Listening tests are not necessarily valid data points. Even objective tests are not necessarily valid data points....but they're better than listening tests.You seem to view subjective testing as more robust than objective testing. I don't understand that.
Why is this concept (and my point of view) so difficult to grasp?It's easy to dismiss my opinion as that of an "amateur psychologist." I had hoped for better from you.
Cheers,
Dave.
Edits: 11/02/14Follow Ups:
I have more respect for my hearing than perhaps I should, but there have been years where I heard more test tones than music. I trained myself to listen to particular aspects of sound quality rather than the emotional gestalt of the music when doing critical listening.
Having strong measured distortion on the overall signal does not necessarily do any harm to the low level resolution at practical listening levels. I found that some noise can be innocuous and easily separated from music by the mind, so I wonder what the point is in lowering it any further. I keep wondering about the fact that feedback lowers distortion measurements yet outside of the bass frequencies the results can sound worse. I played with toasty bias settings that had profound effects on the spatial and tonal quality of the music in general but caused obvious distortion at high volume that wasn't there at low bias settings. obviously the amp was being cooked so that heat dissipation and PS current capacity were challenged at less than half the rated output at low (factory) bias. But the payoff in the lower volume level was far more important for performance.
Which raises the question of what measurements matter and is all noise and distortion equally "bad"?
I am doubting that we know what to measure and perhaps more importantly, how to weight it.
As far as listening evaluations are concerned I take them more seriously if they are repeatable and independently observable by different people. Particularly if that is in different systems. More importantly, I take them more seriously if they are offering particular SQ descriptions. Instrumental locations on the soundstage, tonal and textural correctness of instruments and transient structure like piano hammer strikes, string picking and valve clap sounds on woodwinds. FR extension descriptions and detail retrieval. I find that those are not so subjective and have value while "good/better" and "bad/worse" gestalt descriptors are useless and it is beyond me why anyone would conduct a listening test with those as output.
The worst thing is that even cheap relatively early digital gear tested better than analog - tape or LP, with better S/N or dynamic range and less THD not to speak of the lack of rumble and wow and flutter, and fuller extension of FR, and lack of end of side distortion, but was entirely unlistenable unless you chose deliberately unresolving speakers with good dynamics. For a number of years in the late 80s I recorded all my CDs to tape - R to R and then a Nak 3 head cassette with metal tape. I didn't mind the minor loss of detail and some compression so long as the edge was taken off. I very much minded it in recording LP.
That brought me to the conclusion that we are just not covering psychoacoustically significant measures in the standard testing of audio gear. That not all distortion is important, that not all noise is intrusive, and that something is wrong with subtractive distortion canceling schemes - feedback (particularly global), balanced circuits - to some extent - and even DC servos, though they eliminate coupling caps.
I wonder why we should care to have less than 0.1% distortion and better than 90db dynamic range or S/N.
I am constantly bothered by the fact that pros do not try to figure out what to measure in order to tell what it is that is so consistently off in digital and feedback. I can say that whatever it is that is so wrong in PCM digital, it is not there in DSD playback via non-PCM chips as in the PS Audio Direct Stream.
Does anyone know of a simple inexpensive single ended pre and power amps with no feedback to use in my setup - with the amp driving the mids (96 db sensitivity). Tube or SS. If necessary I am willing to put my jittery hands and poor eyesight to use to build it myself if there is some tried out and tested design I can be pointed to.
BTW here is one way to measure what is going on between orientations of caps:
"...you can do a simple test to determine which is the outside foil terminal. Set the scope up to the most sensitive vertical scale (20mV or less, preferably) and connect the scope probe across the capacitor (ground to one side of the cap, probe tip to the other). Grab the capacitor tightly with your fingers, and note the amplitude of the induced 60Hz AC signal (or 50Hz if you are on the other side of the pond). While still holding the capacitor tightly, reverse the scope leads and you should see a dramatic difference in the amplitude of the induced AC signal. The orientation with the lowest induced signal is the one you want, and the ground lead of the scope is connected to the outside foil in that position. Mark it, and connect that side of the cap to the lowest impedance point in the circuit, typically the driving source plate when used as a coupling cap, or the grounded end if used in a shunt position. ... "
http://www.aikenamps.com/index.php/where-to-connect-the-outside-foil-on-capacitors
It is an RF shielding effect where the RF exposed outer foil can be connected either to ground, a power rail, or the low impedance side of a circuit to minimize RF injection into the circuit.
The fact of AC has nothing to do with the audible effect.
Do you even read my posts?
How about this one from the other day regarding capacitor shielding?
http://www.audioasylum.com/forums/MUG/messages/21/212903.html
"The fact of AC has nothing to do with the audible effect." I know you didn't mean it that way, but that sounds like you're agreeing with me. :)
This is ridiculous. You HAVE to stay focused and quit putting words in my mouth.
Dave.
Actually, I was hoping to find a physics discussion about transients which don't have a sinusoidal signal and are not strictly AC and how they might be affected, since imaging is largely dominated by transients and these are typically < <1ms in the rise portion and <5ms in the release portion so localization and size determination, which occur prior to fine intensity determination and the later pitch identification, might be somehow affected by the asymmetry of internal and external plates. Didn't find anything
Sorry, I missed that one.
I didn't intend to put words in your mouth. I just looked up the issue and found a good discussion of it so appended it to my long winded blathering about decades of frustration.
No, You got me all backwards.
Maybe I was too unclear in my translation from my native Swedish to English-
Sorry in that case!
The one who succeeded was the one who didn't know it was impossible.
Sorry, responded to the wrong post.
That post was meant for Satie. I'm sure he will figure that out....with some subjective evaluation. :)
Cheers,
Dave.
Hehe!
Thanks. Got a bit worried there for a moment. :)
The one who succeeded was the one who didn't know it was impossible.
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