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In Reply to: RE: I'll let Brad expand on his comments posted by AJinFLA on June 02, 2007 at 15:41:53
I was responding to the topic of the post.
rw
Follow Ups:
You posted quotes by MC as if they were of some significance then clammed when asked about them. No answers to the questions of what *you* linked.
Your personal experience with one 70's amp has what relevance to the topic?
cheers,
AJ
Absolute Perfect hearing and audio memory 24/7
Just thought you read the two short posts and gleaned the importance. Here are two quotes that summarize the content:
Fidelity to an oscilloscope is not the same as fidelity to a human listener. Types and levels of distortion that look to be of no consequence on a computer screen can have profound effect on the listener...
See Andy, I don't believe in Euphonic distortion. I believe in distortion you can hear (bad) and distortion you cannot hear (good). The oscilloscope doesn't discriminate between the two. However; through correlation of listening and measuring we can. Based on the one real study I have read that attempted to do a decent job of this (Cheever) he found that the TYPE of distortion is more important than the level. He also surmized that the fundamental linearity of an amp (ie. open loop) is key to that amp delivering a natural distortion spectrum that our brains can largely ignore.
My Crown amp measured great and performed poorly. Back to that notion of the kind of distortion is more significant than the quantity when one factors human perception.
rw
From *your* links:-
- if a piece of gear measures nearly perfect and yet still doesn't sound right (subjectively speaking)
Doesn't sound right (subjectively speaking) - to who?
- Why is another piece of gear measureably further from an exact replication of the source material subjectively much closer?
Subjectively much closer - to who?
- The result was often poor sound quality. Poorer measuring but better sounding amps
Poor sound quality and better sounding amps - to who?
- Who are the engineers designing high fidelity gear for, the test bench or human listeners? When designers make a real effort to apply what has been learned to date about psychoacoustics to electronics design then we might begin to see a directed progress in sound quality
- Sony uses noise shaping in SACD, not to eliminate the problems but to push them where they are outside human (listener) perception
Huh???
You felt these important enough to link. Don't run and hide, just answer them if you can. If you can't, well, that would make a lot of sense too.
Then we'll move on to your next quotes that summarize the content.
cheers,
AJ
Absolute Perfect hearing and audio memory 24/7
Doesn't sound right (subjectively speaking) - to who?That would be everyone on the planet who ever heard a 1971 Crown amp using massive amounts of NFB around a Fairchild ua739 op amp. Dreadful. By the nature of his remarks, Mr. Danley is familiar with this breed. The product underwent two revisions (apparently Crown agreed with the consensus) over its lifespan before getting put out to pasture. Early 70s SS using op amps was brutal. I also had a PAT-5 in the day which was quickly converted to a Jensen's FET-5 replacing the horrible LM-301s with LF-356s. Much better.
Who are the engineers designing high fidelity gear for, the test bench or human listeners?
That depends upon the designer. Clearly Crown falls into the former group.
Sony uses noise shaping in SACD, not to eliminate the problems but to push them where they are outside human (listener) perception.
It is a variation of dither.
rw
- if a piece of gear measures nearly perfect and yet still doesn't sound right (subjectively speaking)
Doesn't sound right (subjectively speaking) - to who?
ES - That would be everyone on the planet who ever heard a 1971 Crown amp using massive amounts of NFB around a Fairchild ua739 op amp. Dreadful. By the nature of his remarks, Mr. Danley is familiar with this breed. The product underwent two revisions (apparently Crown agreed with the consensus) over its lifespan before getting put out to pasture.
So when an audiophile refers to a piece of gear that measures nearly perfect, they are referring specifically to a 1971 Crown?
The sound of a 1971 Crown explains all audiophiles lamenting about SS sound, even today? All SS amps sound like a 1971 Crown? All SS amps use "massive NFB around a Fairchild ua739 op amp"? I though Mr Danley mentioned some other measurements that may be not so stellar? Do all tube amps today sound as awful as a 1971 or other model? A 1971 Crown measures in every parameter the same today as a 2007 Crown?
- Why is another piece of gear measureably further from an exact replication of the source material subjectively much closer?
Subjectively much closer - to who?
ES - That depends upon the designer. Clearly Crown falls into the former group.
Designer? The question is who gets to judge what is "subjectively much closer". Which listener? What qualifications? Crown's amp from 1971 determines all? It is all encompassing to everything? It answers who gets to judge what today?
- The result was often poor sound quality. Poorer measuring but better sounding amps
Poor sound quality and better sounding amps - to who?
ES - No answer.
Once again, I'll ask you, WHO gets to judge what is "Poor sound quality and better sounding". Which listener? What qualifications?
- Who are the engineers designing high fidelity gear for, the test bench or human listeners? When designers make a real effort to apply what has been learned to date about psychoacoustics to electronics design then we might begin to see a directed progress in sound quality
- Sony uses noise shaping in SACD, not to eliminate the problems but to push them where they are outside human (listener) perception
Huh???
ES - It is a variation of dither.
Are you purposely being dense here? I highlighted the contradiction and absurdity of the statements. How did Sony manage "not to eliminate the problems but to push them where they are outside human (listener) perception" when "engineers designing high fidelity gear for the test bench" when they don't have a clue how to "make a real effort to apply what has been learned to date about psychoacoustics to electronics design"? Did they get plain lucky staring at their oscilloscopes? Pure chance? How did they or any other reality/measurement based manufacturer know anything about psychoacoustics applied to electronics?
cheers,
AJ
Absolute Perfect hearing and audio memory 24/7
So when an audiophile refers to a piece of gear that measures nearly perfect, they are referring specifically to a 1971 Crown?
Choose whichever poor example of audio amplification you please that illustrates the irrelevancy of THD. I chose one that I knew well from my yout'. You'll note that I don't have a blanket condemnation of SS. Look at my systems. Each one uses SS amplification of some sort. Actually, worse existed at the time and I was able to avoid it -- despite my faith in the value of THD. The dealer also sold Harman-Kardon and quickly steered me to a Citation 11 for the same jack. It was he who warned me of what he came to call...naturally, I'm talking about the ICK preamp, aka the IC-150. It looked cool and sported the lowest THD spec in the industry at the time. Distortion quoted from the manual: "essentially unmeasurable; IM less than 0.05% at rated output with IHF measurement (typically under 0.002%)." Yet this is one of the worst sounding components you can find. Ever. But, it did measure well. Goody. One reviewer likened the top end to getting "drilled by the Dentist without anaesthesia". The funniest story is by an ex-dealer of Crown equipment of that day:
Grounds for Termination of Employment
LOL!
A 1971 Crown measures in every parameter the same today as a 2007 Crown?
I'll have to give them credit and acknowledge that over the past three decades, their philosophy has likely evolved closer to the 'human listener" perspective as you call it. Most of their current units measure worse . At least when we're referring to THD. Where the D-150's THD spec was 0.05%, that of a current mid priced amp is 0.1%. Hopefully, they sound better. :)
Poor sound quality and better sounding amps - to who?
Is there an echo in the room?
How did Sony manage "not to eliminate the problems but to push them where they are outside human (listener) perception" when "engineers designing high fidelity gear for the test bench" when they don't have a clue how to "make a real effort to apply what has been learned to date about psychoacoustics to electronics design"?
The first response that comes to mind (with a smile on my face) is:
Jane, you ignorant slut!
I'll be happy to address the first (non-imaginary) part of the interrogation. The principle is quite simple to me and used elsewhere in audio engineering. Conceptually, you are describing how a class D switching amplifier works. The switching frequency selected is always over the 100 kHz (inaudible) range. It is the designer's sincere hope that his low-pass output filter will fully remove all of the $hit, er modulation noise inherently present in the output signal. Alas, no one has yet done that. You see that as "fuzz" on a square wave. The question as to the audibility of that "inaudible" junk (or the unintended consequences of) is certainly a lively topic of debate.
rw
'
Absolute Perfect hearing and audio memory 24/7
What does that have to do with the answers to your questions?
Don't give up so soon on trying to understand the underlying concept behind Sony's noise shaping and the conceptually equivalent example I provided. Both don't eliminate the noise - they simply move it above the audible band. Why is that so difficult to understand? Search for "noise shaping" and "dither" in the first link.
Noise Shaping
Here's a Sony document that says basically the same thing.
Pushing noise above the audible range
rw
Surely you are jiving or something, Isn't the "human element" the reason why noise is moved outside the audible range, moving noise out of the audible range is equivalent to eliminating noise from the audible range , different terminology, same meaning. You want to have your cake and eat it. No way howsay!
Music making the painting, recording it the photograph
You have exactly restated the point morricab made, to which I agreed and quoted - and which AJ doesn't seem to get. Thus the topic of my last post.
If it is impossible to make a truly distortion free amplifier, then isn't it smarter to put that distortion in the blind spot of human awareness rather than make it really small but sitting right in the open where even very tiny levels are obvious? Kind of how Sony uses noise shaping in SACD, not to eliminate the problems but to push them where they are outside human perception.
Strictly speaking, the noise is still there. It's there on the signal and visible on scopes. As morricab pointed out, it is outside human perception. I agree. Again. You concur! Great.
rw
nt
Music making the painting, recording it the photograph
Circular reasoning requires that one begins with an unsupported assumption and uses that assumption later as "proof" to some other conclusion. Like SM used to do with cables. His POS cables are perfect, so why would using an extra set have any effect on the sound? His Citation 11 preamp is perfect so why can't you assume that his other mediocre preamp is likewise perfect because he can't hear the difference when one is piped through another? Great real examples of circular reasoning.
Neither morricab nor I have made any assumptions as to the existence of distortion present in all amplifiers, the existence of noise present in Sony's DSD process nor for the modulation noise present in all class D amps. While the designers *wish* the measurable noise was imaginary, alas it is not. Nice try though. :)
rw
Keep up the good work Estat, I am on holiday and not in the mood to duke it out with morons like AJ and AH. I just wanted you to know that I am agreeing with your arguments right down the line. We most definitely see eye to eye (about speakers too!). The ironic thing is that AH actually has really good speakers (Audiostatics). I have no clue what AJ is doing with audio...making a sonic mess most likely.
MC:I am on holiday and not in the mood to duke it out with morons like AJ and AH
TAH: You are on holiday and have no time to duke it out yet you found time to respond four of my threads, three within the 2 hours! In addition you respond to a couple of AJ's posts with the same timeframe. So if you had time, what will you do, respond to all of them? You are too funny!
Music making the painting, recording it the photograph
You are not content making a circular argument, you go one better and make a tangential one :0. I see why DB and SM were rather very short when replying your posts, You make it raison d'etre to be either tangential or circular, whichever suits your purpose at the time.
Let's rewind and go back AJ original post.
MC - Who are the engineers designing high fidelity gear for, the test bench or human listeners? When designers make a real effort to apply what has been learned to date about psychoacoustics to electronics design then we might begin to see a directed progress in sound quality
MC - Sony uses noise shaping in SACD, not to eliminate the problems but to push them where they are outside human (listener) perception
Huh???
AJ is highlighting the contradiction in MC comments, on the one hand, he claims that designers do NOT apply psychoacoustics to their audio designs, whilst unwittingly commenting somewhere else on how Sony use noiseshaping push (eliminate? the exact wording is irrelevant) noise outside of human (listener) perception. In other words apply psychoacoustics to audio design. Therefore, the exact terminology describing noiseshaping is auxiliary to the point, it is simply an illustration to highlight inherent contradiction in MC's commentary.
Now, you come along and dance around AJ's comments, ignoring the substantive issue. But proceed to make circular arguments about noiseshaping terminolgy. Eliminate, push further up or whatever word you choose to use, what does it matter, EStat? The point is that they applied psychoacoustic knowledge to audio design.
My comments
"Isn't the "human element" the reason why noise is moved outside the audible range"
are intended to reiterate that the "human element" is the application of psychoacoustics to audio design not further your circular and now tangential comments on noiseshaping. The semantics of the noiseshaping terminology is auxiliary to the main issue. So please stop playing dumb.
Music making the painting, recording it the photograph
"he claims that designers do NOT apply psychoacoustics to their audio designs,"
I make no such claims whatsoever. Don't try to put words into my mouth. It is clear that some designers DO take some of these things into account just not systematically. Sony may or may not have done psychoacoustic tests to confirm the audibility of noise shaping but maybe they simply assumed that these digital artifacts were audible and felt it would be better if they could shift them to higher frequencies beyond audiblity of normal humans.
You can test noise shaping yourself if you like. The Behringer DEQ 2496 has a noise shaping function and it's effect is clearly audible. There are also three dither settings, 16, 20 and 24 bit as well as off. These are also clearly audible. If you can't hear a difference with these settings then i suggest a new amp or better ears.
There is no contradiction in what I am saying or have been saying.
MC: Sony may or may not have done psychoacoustic tests to confirm the audibility of noise shaping but maybe they simply assumed that these digital artifacts were audible and felt it would be better if they could shift them to higher frequencies beyond audiblity of normal humans.
TAH: What a stupid thing to say! After over 30 years of digital audio, Sony was just guessing about the audibility of noiseshaping. Is that how you do it your chemical labs, you foister stuff on the unsuspecting public based on an untested assumption. I will save your blushes and not post any links. Meanwhile I suggest you stop fooling yourself.
Music making the painting, recording it the photograph
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