Re: Hi-fi is a dead subject.
Hey, welcome back. You'll find lots of folks who share your revulsion towards hi-fi on this forum. Start your own cable thread and you'll make some real friends.
wakibaki said:
Hey, welcome back. You'll find lots of folks who share your revulsion towards hi-fi on this forum. Start your own cable thread and you'll make some real friends.
Re: Hi-fi is a dead subject.
Hi wakibaki,
Nice post - first off, I know plenty of engineers and musicians who use tubes and film. Lets not go starting unnecessary battles with jihadists.
Its understandable that an engineer looking in on this mess would be disturbed. We are dealing with humans after all, not electrons - much less predictable, IME.
I see the problems in audio 'hi-fi' as twofold - first, no one has established any agreed upon method for rating better or worse devices. Second, there are tons of people (marketing departments) spouting off whatever they can make up to convince people they should invest in their products, ideas, etc. Look in any audio magazine, it is truly unbelievable what some people will publish. So not only is there a total lack of reliable information, there are all sorts of people spreading misinformation/propaganda. It is no wonder we can't agree on anything.
Perhaps a part of the problem is that hifi audio is a luxury item. There is no reason for the public to fund an academic sector. Luxury items are more about what people think/feel about them then what they actually are. Digital communication technologies are quite different.
I think the sciences of human perception are ripe for exploration, if anyone is up to the task. 😀
Hi wakibaki,
Nice post - first off, I know plenty of engineers and musicians who use tubes and film. Lets not go starting unnecessary battles with jihadists.
Its understandable that an engineer looking in on this mess would be disturbed. We are dealing with humans after all, not electrons - much less predictable, IME.
I see the problems in audio 'hi-fi' as twofold - first, no one has established any agreed upon method for rating better or worse devices. Second, there are tons of people (marketing departments) spouting off whatever they can make up to convince people they should invest in their products, ideas, etc. Look in any audio magazine, it is truly unbelievable what some people will publish. So not only is there a total lack of reliable information, there are all sorts of people spreading misinformation/propaganda. It is no wonder we can't agree on anything.
Perhaps a part of the problem is that hifi audio is a luxury item. There is no reason for the public to fund an academic sector. Luxury items are more about what people think/feel about them then what they actually are. Digital communication technologies are quite different.
I think the sciences of human perception are ripe for exploration, if anyone is up to the task. 😀
Well said; the luxury item is more about the name plate on the front than how much better it is.
I have nothing against people who like X amp, I am more into car amps and I certainly like specific models more than others. Some expensive some not. Then again I don't EQ in the car much so the response they have does indeed sound better because of how they are colored. Just like the old Harmon Kardon home amp I have, it is in the shed because it needs cleaning and the little NAD works ok for the rare times I have to listen to music in the house. The HK will handle the NAD though. I've even thought about running the HK on subs on the HT, a shame but why not use it. I think I need a power center to turn all that stuff on, that would help but I've run out of room.
Some day I will move into this century and get a DSP EQ. It was some other closed thread I read talking about a preamp with a billet machined case? Guy said he wanted it sturdy, I thought to myself aluminum can be welded but I would not toss my amp off a cliff either. I guess it is cool but at 1500 for a case it should be gold plated IMO.
I have nothing against people who like X amp, I am more into car amps and I certainly like specific models more than others. Some expensive some not. Then again I don't EQ in the car much so the response they have does indeed sound better because of how they are colored. Just like the old Harmon Kardon home amp I have, it is in the shed because it needs cleaning and the little NAD works ok for the rare times I have to listen to music in the house. The HK will handle the NAD though. I've even thought about running the HK on subs on the HT, a shame but why not use it. I think I need a power center to turn all that stuff on, that would help but I've run out of room.
Some day I will move into this century and get a DSP EQ. It was some other closed thread I read talking about a preamp with a billet machined case? Guy said he wanted it sturdy, I thought to myself aluminum can be welded but I would not toss my amp off a cliff either. I guess it is cool but at 1500 for a case it should be gold plated IMO.
SY said:
I would put greater emphasis on duh.
And we now have confirmation that the amp wasn’t measured prior to being modded.
🙄
Conrad Hoffman said:
I can't tell you what the amplifier will sound like, but if the THD measures very small, I can tell you how it won't sound - ie, it won't have the coloration associated with high harmonic distortion, either the harsh high order sort or the less objectionable low order sort.
That is why it makes no sense to say the THD measurements help you predict nothing about the amplifiers sound.
If the amplifier produces a high enough THD, then I can say with some degree of confidence that it will sound coloured. There is a big difference between an amp that sounds coloured and one that doesn't (regardless of the nature of the colouration).
So I'm sorry, but your claim that THD does not 'describe at least some aspect of sound quality' is patently false.
Cheers,
Glen
Glen, I don't see where we disagree on all that much. I wouldn't have three different THD analyzers if I didn't find the numbers useful for something. Actually I find the monitor output as useful as the numbers. We do seem to have different ideas in mind as to the meaning of predicting amplifier sound. Just saying it's coloured is, to me, way different than being able to say it's harsh, smooth, subdued, or any of the vague terms everybody uses. So, yes, high THD readings predict that the amplifier isn't perfect. That's not nearly so satisfying as what can be predicted from a tilted, rolled or boosted response curve, or maybe even very low damping factor.
FWIW, my diy amps use very old designs, and are far from blameless. What I should probably do is update them to push the errors well below audibility (I get to choose!) and then the question should be moot. The numbers will then predict with great accuracy that they sound like every other amp with similarly low numbers.
FWIW, my diy amps use very old designs, and are far from blameless. What I should probably do is update them to push the errors well below audibility (I get to choose!) and then the question should be moot. The numbers will then predict with great accuracy that they sound like every other amp with similarly low numbers.
bear...
I am not able to find the actual paper on the "Gedlee Metric" and its experimental justification -- getting senile I suppose. Do you have a link for it? Again I would be most grateful.
I am not able to find the actual paper on the "Gedlee Metric" and its experimental justification -- getting senile I suppose. Do you have a link for it? Again I would be most grateful.
THD is useless as a measure of perceptible significance of distortion. That was clearly shown by Geddes and others. You won't be able to hear 2nd harmonics until it's a good fraction of a percent. On the other hand, crossover distortion can affect sound at lower levels than the ones you mentioned. You could argue that if THD is low enough (and that THD number better be for a 20 kHz full scale output test signal, not the usual 1 kHz), there can't be much other distortion of any kind because this would affect the THD. However, this is not true, because circuits are not memoryless. Thermal modulation of device parameters causes distortion that doesn't much show up on THD, yet is easily measured using the appropriate test. That's just one example.
eStatic said:
Dunno, google Dr. Earl Geddes, it's on his site somewhere, or was last year... probably still there.
There was a post earlier with a link to a paper by him, probably truncate the link and that's his site...?
😀
_-_-bear
READ .. the test was conducted with matched levels at the amps..
I;m tired.. and not going into an hours worth of typing to explain this
Read RC challenge then remove the eq device
that's what i did!!!!
I;m tired.. and not going into an hours worth of typing to explain this
Read RC challenge then remove the eq device
that's what i did!!!!
You've not shown that you matched levels sufficiently well if the 6 V RMS you give is for full scale output (just before clipping) rather than average level of music you listen to.
Do all amps sound the same? Yes.
And some sound even more alike than others! 😛
(For amps that seem to sound alike, listen to track #4 on the CD "Oh Brother Where Art Thou?" Listen to the reverb/room tone on the choir.)
And some sound even more alike than others! 😛
(For amps that seem to sound alike, listen to track #4 on the CD "Oh Brother Where Art Thou?" Listen to the reverb/room tone on the choir.)
- Status
- Not open for further replies.