You may not, but the "delay" thing is a canard indeed. Basic control theory.
The difference is that when you say "hear," you mean "peek," not "perceiving only by ear."
Hi,
You did. Or rather, you implied even ( pair, your words) order HD was O.K.
It is not as it will change timbral accuracy of the instrument. Same goes for odd order HD.
What you meant to say is that we object less to even order distortion as it sounds more pleasing to the ear as opposed to excessive odd order harmonic distortion which is perceived as irritating. (See the SE amp craze for evidence)
At the end of the day distortion is just that; distortion.
Much more malign types of distortions exist and quite often intermixed.
Cheers,
You did. Or rather, you implied even ( pair, your words) order HD was O.K.
It is not as it will change timbral accuracy of the instrument. Same goes for odd order HD.
What you meant to say is that we object less to even order distortion as it sounds more pleasing to the ear as opposed to excessive odd order harmonic distortion which is perceived as irritating. (See the SE amp craze for evidence)
At the end of the day distortion is just that; distortion.
Much more malign types of distortions exist and quite often intermixed.
Cheers,
You are true, sometimes i perceive infra bass with my body.
But, believe me or not, i never listen with my eyes.
I even used to close them, when it was about to build a believable acoustic decor during a mix. You know, the virtual scene on witch the musicians were supposed to play, the side and back walls, the height and the distances, while they were all recorded with close mics ?
Hi,
I read you.
Still this is something I discussed with Tim De Paravicini back in the mid-Eighties in London.
His argument was that some kinds of distortions can't be corrected for by GNFB because of this delay.
Was he wrong in saying so?
My mind and acquired knowledge say yes, my instinct is still doubting....
Cheers,
I read you.
Still this is something I discussed with Tim De Paravicini back in the mid-Eighties in London.
His argument was that some kinds of distortions can't be corrected for by GNFB because of this delay.
Was he wrong in saying so?
My mind and acquired knowledge say yes, my instinct is still doubting....
Cheers,
I certainly agree with this particular point: things can be seriously counter-intuitive sometimes.
OK, non linear elements generating even order dist are supposed to have "benign" distortion products, in particular IM products, supposedly the most harmful.
Here is an example for 4th and 5th order (with this setup, no fundamental is shown, since the interest is elsewhere).
Basically, two sources, one at 1KHz and the other at 1.1KHz are linearly added then processed in a purely non-linear element of a pure and known order.
Because of the way LTspice processes the functions, the 5th is disadvantaged (I didn't care to scale the amplitudes), but the interesting bit is elsewhere: although the 5th's spectrum (right window) is logically somewhat denser than the 4th, the lower frequency products are naturally cancelled: you see nothing at 100Hz and 200Hz.
This is important, because in general, lower order products will be more audible, or at the very least be more identifiable regarding the pitch, which means their dissonance will be more perceivable: even if you can (still) hear 12 or 15KHz, , you are not going to be able to correlate it correctly with a fundamental at 4 or 5KHz.
When you hear a 1KHz signal added to the 4 or or 5KHz fundamental, it will take a lot of masking level to make it disappear.
Now, it works both ways: you'll notice that the odd order distorter creates lots of artefacts around the fundamental, totally absent for the even distorter (this is a pure, idealized situation of course).
This means that even order distortions will be more harmful for a mix of high frequencies signal, whereas odd order distortions will sound more benign for lower frequencies: a counter-intuitive result again.
Morality: all distortions (read non linearities) are harmful in some ways. Nothing is benign, but people tend to like what poisons them, be it crack cocaine, Gevrey-Chambertin or harmonics...
Attachments
Last edited:
I don't thing it is plain wrong.
Call this how you want, phase error or delay between the original and feedback signal. The phase error begin to have an influence around 10Khz for the fastest amps.
Here the response curve at the input of the VAS (Original signal - feedback one) of a 1000V/µs amplifier (simulated):
http://www.esperado.fr/temp/in-vas.jpg
Last edited:
It is a common mis-conception to look at any phase vs. frequency as delay. A true delay is not the correct concept here.
Right too, we can have a delay witch not affect the response curve, but a low pass filter will always affect the phase near its FC. That is what you mean ?
We are blessed in Australia by having excellent value for money wines, makers who consistently create fault free product - I would be struggling to recall a single off wine, over decades of drinking; we are extremely averse to wine snobs, from having local "celebrity" wine buffs, over the years, scorning these types. Biggest 'flaw' is lately creating wines which lack character, largely to placate overseas drinkers,
. I'm reminded of a Colombard wine, made a couple of hours drive away in a cooler area wine area, very low priced. The Colombard grape in Australia has always been a "junk" variety, used for filling el cheapo wine casks and such ... yet this particular wine has intense fruit character - think a high quality NZ sauvignon blanc, as a reference for depth of character - a superb drink.
Last edited:
I do see your point . Mine was what the purpose of it all was . No longer being in sales and have no public contact at work has made my life much easier. Standard question in the vcr era was "This all you have" while pointing at 28 different model . When ask what are you looking for ? Answer I do'nt know. At times does apply here some what .Yes, but that's a different question than "Can I actually hear the difference between A and B?" If you can, then you can move on to which sounds "better" to you. If you can't, then you can move on to issues which actually matter to the sound. Or you can become a high end huckster.
As Esperado points out, by choosing the right source material it's easy to differentiate between different situations. I get the impression that a lot of 'objectivists' get trapped by the term "better", which is far too vague to be useful. A '50s Cadillac is "better" at hiding bumps on the road then a lot of modern cars - but as a piece of engineering, well ...Yes, but that's a different question than "Can I actually hear the difference between A and B?" If you can, then you can move on to which sounds "better" to you. If you can't, then you can move on to issues which actually matter to the sound. Or you can become a high end huckster.
.Infinitely more useful is the term "correct" - is the rendition of a particular musical passage more convincing, more accurate to to your memory of how such should sound?
Where this conversation is missing the bigger picture is that all systems generate a soup, a stew of distortion - it's not just the transfer function in the amplifier that you need to worry about, it's all the failings, weaknesses throughout the playback chain, that all add up and create a dog's breakfast at the driver cone surface - hence the muckiness of much audio that one hears.
The solution is to eliminate as many of the distortion elements that produce this "mess" as possible, and then a far higher standard of sound is heard - even a nominally poorly performing amp, from a measurements POV, can sound very impressive, because most of the extra sludge normally heard has been removed from the picture ...
The solution is to eliminate as many of the distortion elements that produce this "mess" as possible, and then a far higher standard of sound is heard - even a nominally poorly performing amp, from a measurements POV, can sound very impressive, because most of the extra sludge normally heard has been removed from the picture ...
In the audio band- yes, that's incorrect, either what he said or your interpretation. And you know why that is, which is why it surprises me to see you saying that.
edit: I see that Scott has more than adequately addressed this point. I had a similar exchange with someone else (a very smart tube guy) who truly couldn't grasp the difference.
Not consciously, I'm sure. But if you know what A and B are, you automatically cannot judge their sound in an unbiased way. This is true for any sensory issue if I am correct in assuming that you're human.
We are blessed in Australia by having excellent value for money wines, makers who consistently create fault free product - I would be struggling to recall a single off wine, over decades of drinking; we are extremely averse to wine snobs, from having local "celebrity" wine buffs, over the years, scorning these types. Biggest 'flaw' is lately creating wines which lack character, largely to placate overseas drinkers,
I'm reminded of a Colombard wine, made a couple of hours drive away in a cooler area wine area, very low priced. The Colombard grape in Australia has always been a "junk" variety, used for filling el cheapo wine casks and such ... yet this particular wine has intense fruit character - think a high quality NZ sauvignon blanc, as a reference for depth of character - a superb drink.
Frank, you are amazingly consistent. BTW most NZ SB are vinified with cultured rather than wild yeasts to enhance the "cat pee in a gooseberry bush" taste i.e. manufactured and essentially fake taste IMNSHO.
Last edited:
Not quite, a true delay is a linear phase over all frequency and results in a non-minimum phase response i.e. the derivative is a constant and conveys no information to the amplitude response. Think cancellation by echos, at certain frequencies the amplitude can drop to zero by simple subtraction with no poles or zeros.
Last edited:
Not consciously, I'm sure. But if you know what A and B are, you automatically cannot judge their sound in an unbiased way. This is true for any sensory issue if I am correct in assuming that you're human.
SY weren't you the guy who used to say 'don't feed the trolls'. What happened
?Jan
SY weren't you the guy who used to say 'don't feed the trolls'. What happened
Jan
We can all be fooled.
- Status
- Not open for further replies.