I don't think same sound necessarily follows just due to same voltage from source.Conrad Hoffman said:
But, it may be that eventually we should be able to measure what it is that makes different sources sound different. I don't know if that will turn out to be resolution of very small voltage differences.
Salas- I'd like to ponder any topic you like, but I can't read your mind. My skills are in hardware and measurement, so like a carpenter with a hammer, everything looks like a nail to me. Regarding psychoacoustics, there's the issue of how we interpret difference in actual equipment performance- I have to tie this in with measurements or it becomes the chasing of ghosts and no progress can ever be made. I've watched the audio community go in circles on those issues for 30 years or more. Then there's the issue of presentation- the tone of the hi-end salon salesman's voice, the chair you sit in, the weather, the time of day, maybe the claims for a certain capacitor that you know to be in the system- all have a profound effect on what you perceive. Those things can be researched, but not by me. Meaningful data on those issues is difficult and expensive to collect, so we're probably left with using the general understanding of human bias that already exists. The original topic was whose philosophy to trust on capacitors and I don't think we've strayed too far from that, since it involves sound quality, measurements, and perception, but I'll happily go in any direction that's interesting to you.
AndrewT said:
Andrew,
If two sounds are different it is because the air moves differently. That is because the speaker membrane moves differently. That MUST be because the voltage at the speaker terminals is differently. Assuming you use the same speaker in the two cases, that difference in voltage can be measured.
Jan Didden
One vote for unsure. Is 0.005% pure 11th or 13th harmonic distortion audible? 0.005% total 11th and 13th? I don't know, might be on solo tenor or oboe. How about the earlier example of an amp which measures well except during momentary clipping? Your measurements were clean yet the amp sounded 'fuzzy'. The proposed metric could be interpreted to capture this under some operating conditions. If you're keen to enterain completely artificial and 'way out there', how about a 5 kHz level-dependent oscillation in anti-phase between channels which localizes above the listener's head?
I understand the reasoning, a small enough number doesn't require weighting. Would these amps meet your metric?
http://www.edn.com/article/CA6418209.html?ref=nbfe
I understand the reasoning, a small enough number doesn't require weighting. Would these amps meet your metric?
http://www.edn.com/article/CA6418209.html?ref=nbfe
Conrad Hoffman said:
I am interested in you to do an experiment. Just connect 30cm of solid core magnet wire enameled copper passing music through it. Then take it out and connect 30cm solid core silver same d. Listen. If you don't hear anything different don't bother. If you do hear something different, can you please measure it and tell us why and what is happening? Thanks.
rdf said:
Well, he didn't say 0.005%, he said 0.005% DIFFERENCE.
OTOH, clipping of course is quite audible, but that is using your amp outside the design domain. The only option if you want to avoid clipping is getting an amp with higher output voltage. Or turn down the sound
.And to answer your question: anything below 0.1% distortion is inaudible with a controlled, double blind test. Whatever the instrument.
Jan Didden
janneman said:
Then make it the difference between an audibly perfect amp and one with 0.005% 11th or 13th. I didn't read the intent as 0.005% difference between two amps with 5% THD.
OTOH, clipping of course is quite audible, but that is using your amp outside the design domain. The only option if you want to avoid clipping is getting an amp with higher output voltage. Or turn down the sound
Reread Conrad's post. He said the amp sounded muddy and diagnosed it by finding 'fuzz on the waveform under clipping'. He could clarify but at this point it can't be assumed the audibility was only under clipping as that's not what he wrote.
I've measured a few amps that at an operating level with 0.1% total THD have of a huge trail of harmonics past the 10th just ten or fifteen dB below the dominant harmonic, usually the second. Research has demonstrated these are inaubible? I'ld also appreciate pointers to papers demonstrating that flat 0.1% figure.
Hi,
Particularly with higher order harmonics and for short duration (crossover) distortion.
Now, if one were to apply an audibility rating to each of the harmonics and multiply each by that rating and then sum the total, Sigma[k2*H2....kn*Hn]<=0.1% (k2~=1.0) then I would be very tempted to agree, but I have never tried to do any of this, just intuitive guesswork.
I don't think this is true either.
Particularly with higher order harmonics and for short duration (crossover) distortion.
Now, if one were to apply an audibility rating to each of the harmonics and multiply each by that rating and then sum the total, Sigma[k2*H2....kn*Hn]<=0.1% (k2~=1.0) then I would be very tempted to agree, but I have never tried to do any of this, just intuitive guesswork.
rdf said:
You are right, yes. So there may or may not be any connection between the fuzziness at clipping and his perceived audible difference.
rdf said:
Yeah, I've done my measurements also. I know I should provide papers etc. I have them somewhere. Maybe I'll look 'm up. Maybe it wasn't 0.1%, maybe it was 0.2%
Point is, controlled double blind tests show an appalling lack of audibility of THD we normally consider as huge. Heck, even Ivor Tiefenbrunn (founder of Linn) couldn't detect the difference when an early SONY PCM-1 A/D -> D/A chain was inserted in his sytem. I have that also somewhere. Are you really expecting me to dig it out again for the umpteenth time? Why me always?
Jan Didden
I love those thread!
I have a friend that always exagerates when telling stories. He likes telling a good story, and puts too much extra.
I think we are like that, the audiophiles on the forums. When we describe differences, it's always huge! Always night and days.
Nobody likes to say that they can't hear any differences between their new component and the old one, it's not a good story!
Fictional example: Hey guys, I just purchased 4 new titanium feet at 40$ each for my turntable. Guess what, I don't hear any difference!
The answer is always: there must be something wrong in your setup, on my system, the difference is HUGE!
Yeah right!
And i'm guilty, i've done it in the past. I just bought a new cartridge, spent an hour setting it right. And play: Wow! great sound. After a few hours of happy listening, on go on the forums and tell everyone that this is indeed a great cart, much better than my old one. etc.
Than a few days after, I put the old cart back, and guess what: the sound is not very different...well, I would even says that the sound is better with the old cart finally...
So that's how belief spread. But you knew that anyway.
Personnally, I think that these capacitors "could" make differences, but frankly, i'm not sure. And I also see a lot of people repeating the same old promotional BS that they read somewhere else. For example, Auricaps and their colored leads. How many times have you seens post asking where do you put the black lead, on the speaker side, or on the amplifier side? And some people are actually answering seriously that the black lead should always be connected to the speaker side, exept in amplifier coupling where the black should be positive, and whatever...
My opinion is that subjective listening does not worth much. I am generally happy with my system, but the other day, i hated the sound. Today it's good. Last year after being away from home for two weeks, I came back and thought my system was great! But not after 4 hours of listening.
These are HUGE differences! But 100% in my head.
F
Hey, i cannot hear any difference if I leave my CD player on all the time or if I turn it off after each use. Am I the only one?
I have a friend that always exagerates when telling stories. He likes telling a good story, and puts too much extra.
I think we are like that, the audiophiles on the forums. When we describe differences, it's always huge! Always night and days.
Nobody likes to say that they can't hear any differences between their new component and the old one, it's not a good story!
Fictional example: Hey guys, I just purchased 4 new titanium feet at 40$ each for my turntable. Guess what, I don't hear any difference!
The answer is always: there must be something wrong in your setup, on my system, the difference is HUGE!
Yeah right!
And i'm guilty, i've done it in the past. I just bought a new cartridge, spent an hour setting it right. And play: Wow! great sound. After a few hours of happy listening, on go on the forums and tell everyone that this is indeed a great cart, much better than my old one. etc.
Than a few days after, I put the old cart back, and guess what: the sound is not very different...well, I would even says that the sound is better with the old cart finally...
So that's how belief spread. But you knew that anyway.
Personnally, I think that these capacitors "could" make differences, but frankly, i'm not sure. And I also see a lot of people repeating the same old promotional BS that they read somewhere else. For example, Auricaps and their colored leads. How many times have you seens post asking where do you put the black lead, on the speaker side, or on the amplifier side? And some people are actually answering seriously that the black lead should always be connected to the speaker side, exept in amplifier coupling where the black should be positive, and whatever...
My opinion is that subjective listening does not worth much. I am generally happy with my system, but the other day, i hated the sound. Today it's good. Last year after being away from home for two weeks, I came back and thought my system was great! But not after 4 hours of listening.
These are HUGE differences! But 100% in my head.
F
Hey, i cannot hear any difference if I leave my CD player on all the time or if I turn it off after each use. Am I the only one?
If we are to use words like psychoacoustics, at least use them right. (rdf got it right with "New work must have been part, for example, of the development of lossy codecs which is essentially the art of hiding distortion.")
"There are true psycho-acoustic effects introduced by the brain. For example, when a person listens to crackly and needle-on-vinyl hiss-filled records, he or she soon stops noticing the background noise, and enjoys the music. A person who does this habitually appears to forget about the noise altogether, and may not be able to tell you after listening if there was noise present. This effect is called psycho-acoustical masking."-- http://en.wikipedia.org/wiki/Psychoacoustic_model
"There are true psycho-acoustic effects introduced by the brain. For example, when a person listens to crackly and needle-on-vinyl hiss-filled records, he or she soon stops noticing the background noise, and enjoys the music. A person who does this habitually appears to forget about the noise altogether, and may not be able to tell you after listening if there was noise present. This effect is called psycho-acoustical masking."-- http://en.wikipedia.org/wiki/Psychoacoustic_model
rdf said:
Its not hiding distortions, its hiding harmonics and unrelated tones that are masked by the louder sounds and/or in the same freq bands. (I guess it is distortion, but linear distortion, and generally in these posts we talk about non-linear distortion).
So, yes, there is new work done. Lossy codecs work precisely because we can be fooled to a great extend.
Jan Didden
Ok, I had to go back and read my own post regarding the amplifier. I referred to fuzz on the *peaks" of the signal- nothing to do with clipping. There was just some problem with stability as the slew rate of the waveform varied going over the top, on certain loads. I might add that this was at a level that would have been impossible to see on an 8 bit digital scope, or on anything with a slightly fuzzy trace to begin with- most modern analog scopes.
Slightly OT, I'm amazed at what almost anybody can accomplish today using good sound cards and software. When I was doing more speaker work, I would have killed for that capability. I thought I was doing great to score a used GR third octave analyzer and recorder many years ago. I haven't tried using the sound card based spectrum analyzer on amps yet, but it's certainly another tool in the collection.
I'm a nice fish, and I take the bait quite easily. I just happen to have about 40-50 cm of 99.9% pure silver tubing about 1 cm in diameter, left over from another project. Several pieces in fact. That should address conductor material and skin effect, both of which I'm a skeptic on when it comes to audio. Just where would you like me to put it? No, wait, let me rephrase that! Just how would you like me to incorporate that in my music system? I use separate components with a 3-way 4th order active crossover and separate amps to a Morel tweeter, a Dynaudio mid-bass, and an acoustic suspension box of ill repute (my older bass speakers disintegrated over time and these were the emergency replacement- they still sound pretty decent). Pick the location and the physical arrangement.
Just to keep on topic, here's something interesting concerning capacitors. I like capacitance bridges. Digital "bridges" aren't bridges, but that's another topic. When you use a real bridge to measure a capacitor it basically matches the cap against a reference cap of extremely good quality, and a resistor or capacitor to match the dissipation factor. The bridge is adjusted to null and the values read. Here's the interesting part few people notice. You often can't completely null the bridge, only find a minimum. If you look at the residual signal on a scope, you're seeing (I believe) nonlinearities, i.e., distortions, in the capacitor. Older bridges can handle a lot of voltage, up to 700Vpk on some, so we can test at realistic signal levels, regardless of amp type and cap location. It might be interesting to see if there were some correlation between the bridge residual, and what people claim to hear from various dielectrics.
Regards,
CH
Slightly OT, I'm amazed at what almost anybody can accomplish today using good sound cards and software. When I was doing more speaker work, I would have killed for that capability. I thought I was doing great to score a used GR third octave analyzer and recorder many years ago. I haven't tried using the sound card based spectrum analyzer on amps yet, but it's certainly another tool in the collection.
I'm a nice fish, and I take the bait quite easily. I just happen to have about 40-50 cm of 99.9% pure silver tubing about 1 cm in diameter, left over from another project. Several pieces in fact. That should address conductor material and skin effect, both of which I'm a skeptic on when it comes to audio. Just where would you like me to put it? No, wait, let me rephrase that! Just how would you like me to incorporate that in my music system? I use separate components with a 3-way 4th order active crossover and separate amps to a Morel tweeter, a Dynaudio mid-bass, and an acoustic suspension box of ill repute (my older bass speakers disintegrated over time and these were the emergency replacement- they still sound pretty decent). Pick the location and the physical arrangement.
Just to keep on topic, here's something interesting concerning capacitors. I like capacitance bridges. Digital "bridges" aren't bridges, but that's another topic. When you use a real bridge to measure a capacitor it basically matches the cap against a reference cap of extremely good quality, and a resistor or capacitor to match the dissipation factor. The bridge is adjusted to null and the values read. Here's the interesting part few people notice. You often can't completely null the bridge, only find a minimum. If you look at the residual signal on a scope, you're seeing (I believe) nonlinearities, i.e., distortions, in the capacitor. Older bridges can handle a lot of voltage, up to 700Vpk on some, so we can test at realistic signal levels, regardless of amp type and cap location. It might be interesting to see if there were some correlation between the bridge residual, and what people claim to hear from various dielectrics.
Regards,
CH
FWIW, I measured the silver tubing. It's 0.386" OD, with a 0.008" wall. Lengths are about 1.8', for a resistance of 0.0015 ohms. Even with the thin wall, that's about the same as AWG9 copper wire. It would be really nice if the comparison method involved headphones, as I think I can resolve far more with those, but any sensible test of the pieces will be considered. Even with the large diameter, spaced an inch apart, the capacitance would be (if I figured right) only about 9.5 pF in air.
Quince said:
AndrewT said:
jcx said:
rod tends to 'reinvent the works of others',
and has a definite, mid-fi, mindset. (won't/can't hear).
as capacitors go, rod is 27 years, too late-
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Answer: Yes, you have. But your "great" scientists were not able to reconstruct the skeletons complety, because they wanted to reconstruct reptilian animals, not intelligent beings. You would laugh if you would know how many of the (especially small) saurian skeletons in your museums are totally wrong constructions of never-existing beings, because you used many bones which didn´t really belong together and sometimes you made artificial bones if something was missing you needed to construct an "animal" saurian. Many of your scientists are aware of this problem, but they don´t make it public, because they can´t explain it and they claim, that the right bones were just missing and their reconstruction is right. Many bones of us were used for Iguanodon reconstructions, for example the hands with the visible thumb (look at an Iguanodon in a museum and you will see that I´m right.) A scientist in the country you call United States had build a nearly correct skeleton of our kind some years ago, but the local government (which is partly aware of our existence) confiscated the reconstruction. As we live today (and since thousands of years) nearly completely beneath the earth, you will not find any cadavers or skeletons of us.
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