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BillB
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Hearing stuff never heard before!

I'm hearing stuff I've never heard before! I'm making out lyrics that I didn't know before, and other musical details. It's a knockout! I do it by listening to my big rig, my little rig, my iPod, my lousy computer speakers, my mediocre car stereo. Clearly - different systems have different responses and some of those different peaks in response (and other system variations) will differently expose parts of the music.
Thus - when a $20K speaker system gives a reviewer a sense of hearing something new compared to his $15K reference - take it with a grain of salt. He might hear a similar difference with a less expensive speaker too.

Buddha
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Re: Hearing stuff never heard before!

Beautiful!

Different systems have different things they emphasize, yes.

Great post. I hope it generates many replies.

I hear stuff in my car I don't hear at home - it's flawed, but "different."

Perhaps it trumps ultra high end, sometimes!

Cheers, man.

(The bummer is, now I dread the AVA/Legacy diarrhea we are about to elicit.)

judicata
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Re: Hearing stuff never heard before!

I always wonder what would happen if we stuck every single component together, which during use some reviewer had "heard things never heard before" and slapped them all together. I think maybe there'd be a black hole.

Buddha
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Re: Hearing stuff never heard before!


Quote:
I always wonder what would happen if we stuck every single component together, which during use some reviewer had "heard things never heard before" and slapped them all together. I think maybe there'd be a black hole.

We'd hear everything, all at once.

It would be the same as hearing that joke Monty Python talked about.

I've known people who tried it...they went mad.

Mad.

judicata
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Re: Hearing stuff never heard before!

Maybe it's like a Large Hadron Collider on LSD?

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
He might hear a similar difference with a less expensive speaker too.


Good point. Some cheap speakers have an intentional resonant peak around 6 to 8 kHz to add phony "clarity," and that can make lyrics and other details easier to hear. I don't want speakers like that! But they can still be very clear sounding.

--Ethan

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Re: Hearing stuff never heard before!

Now there is an elitist comment from Ethan.

How dare a manufacturer enhance a product just to make it sound good !!!

This elitism conveniently forgets that a large percentage of our listening material is flawed, live music often sounds like crap live !!!, CD's are massively compressed, as a famous movie quote " You cant handle the truth "

Im all in favour of great sound, but dont knock lower end companys who use tricks to make their products sound better within a budget.

How can clarity be phony ??

Alan

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
How can clarity be phony ??


Great question, though I don't understand why you had to insult me by saying I'm elitist.

The problem with phony clarity is it often makes some recordings sound much worse. In my example of an 8 KHz resonant boost, that can sound terrible on some types of cymbals, or on vocals that are already at the edge of being sibilant.

A perfect example of phony "enhancements" is Bose table radios. To an experienced listener they seem to have a surprising amount of bass for their size. But experienced listeners quickly recognize that the bass is in fact artificially tubby in the 150 to 250 Hz range. I see this in cheap boom boxes and car radios too. The mid-bass is exaggerated so it sounds full to newbies until they learn what to listen for by hearing a good system.

--Ethan

tom collins
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Re: Hearing stuff never heard before!

ethan: how right you are. we recently went on a vacation and the people had bose 201 speakers hooked up to the cd/dvd player (obviously a system no one would steal). my wife (who should know better) thought the people had a "really good stereo". i said, honey, can you tell one note from the next or does the bass just sound loud. she got it shortly thereafter. the same thing happened with one of those wave radios. my thinking is just give me what is correct as far as it can go for what i can afford. if i can't afford to get to 20hz sounding correct, than give it to me straight to 40hz or whatever my budget can take.

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Re: Hearing stuff never heard before!


Quote:
if i can't afford to get to 20hz sounding correct, than give it to me straight to 40hz or whatever my budget can take.


Great phrase.

dcstep
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Re: Hearing stuff never heard before!


Quote:

Quote:
How can clarity be phony ??


Great question, though I don't understand why you had to insult me by saying I'm elitist.

He didn't say you're elitist, he said that you made an elitist comment. There's a big difference.

You're always getting your panties in a wad because you either can't read or you like to twist everything anyone says that not exactly aligned with your view.

Dave

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
He didn't say you're elitist, he said that you made an elitist comment.


And the difference is? Who besides elitists make elitist comments?


Quote:
You're always getting your panties in a wad because you either can't read or you like to twist everything anyone says that not exactly aligned with your view.

Speaking of "views" Dave, there are several outstanding challenges I've made in response to your posts, and you've ducked every single one of them. I do get my panties in a bunch when someone calls me wrong, then when I ask to explain how I'm wrong and what's right they don't answer. You've done that several times. If someone has no answer and realizes they have no answer, the smart - and civil - thing to do is stop calling me wrong. At least until you can explain why I'm wrong. So let me post my most recent challenge to you again, repeated below. If you can't answer my questions, do me a favor and stop calling my views on audio wrong. Deal? Thanks.

--Ethan


Quote:
Dave, I have $100 that says you have no idea what jitter sounds like, have never heard it, and could not distinguish severe jitter from no jitter. Heck, when did I ever say I can't explain jitter? I know exactly what jitter is, and I know exactly what causes it! Do you?

...

Dave, I try hard to be polite and respectful, even when I know people are talking out their butt as happens often in all audio forums. If you disagree, then the burden is on you not just to say I'm wrong, but to explain why I'm wrong and also explain what is right. You haven't done that once. If you can explain what jitter sounds like, and tell me why you're certain that what you heard was actually jitter and not something else, that $100 is yours. No kidding.

dcstep
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Re: Hearing stuff never heard before!

Ethan, contact your mom if you want to talk to someone that gives a shit about your silly challenges.

Dave

dcstep
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Re: Hearing stuff never heard before!

BTW, when did you and I ever talk about jitter??? How 'bout a link?

Dave

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
Ethan, contact your mom if you want to talk to someone that gives a shit about your silly challenges.


Exactly. You have no answer, you know you have no answer, yet you disagree and call me wrong and duck the issue.


Quote:
BTW, when did you and I ever talk about jitter??? How 'bout a link?


Your post #50716 toward the end of THIS thread.

--Ethan

dcstep
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Re: Hearing stuff never heard before!

Here you go shit-for-brains, I said:

"When did jitter become a non-issue??? This is another Ethanism, he can't explain it so it doesn't exist."

I never said that I've heard jitter. I don't OWE you an answer to your stupid question. Just because I've never identified it in a listening test doesn't mean it doesn't exist. Your dismisal of jitter calling it a "non-issue" is still unsupported. You were merely trying deflect from a weak position by diversion.

What did your mother say about your challenge?

Dave

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Re: Hearing stuff never heard before!


Quote:
Here you go shit-for-brains

Please stop the name-calling.

tom collins
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Re: Hearing stuff never heard before!

thanks, oh antlered one. just the strait cowpatty.

CECE
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Re: Hearing stuff never heard before!

Hmm, just cus I can't hear it, doesn't mean it doesn't exist!!! Thata would mean if you can't hear it Ethan is correct, it's not an issue, it doesn't effect things you think you hear, you think it matters cus teh pundits of bable in audio mags keep telling you it matters, so you can buy teh next upgrade of a product. If you didn't hear it, then it doesn't matter, unless of course, no matter if it's audible, and some nudnick writes about how it matters, you jump on the train. Hmmm, this could equate to WIRES, since the wire scammers keep telling you how much it matters, you agree, even though you ain't hearing anything related to a wire sound. Maybe the audiophile crowd is really a bunch of gullible fools. great quote just cus' I can't hear it doesn't mean it doesn't exist, but it still has to be fixed, cus some writer tells me it matters. dcstep is a perfect example of a foolish audiophile. you claim Ethan can't explain it, so it doesn't exist, but YOU can't hear it and it still exists!!! Even though it doesn't if you can't hear it, since I thought what you hear means more than measurements, in audioflakedom world. If you don't hear it, it doesn't exist, right. Like why vinyl is so much better than digital, yet it measures like crap (cus it is) but so many audiofools say it's sounds better. dc is doing a politician wants it both ways, is he bi? amp'd?

CECE
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Re: Hearing stuff never heard before!

Is shit for brains a name or a description of intellect? Shit head comes from what Latin word?

CECE
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Re: Hearing stuff never heard before!

Shiteous Obliskeous

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
you claim Ethan can't explain it, so it doesn't exist, but YOU can't hear it and it still exists!!!


Good point. Belief systems sure are strong and strange. Also, I can explain jitter in excruciating detail. But the causes of jitter are irrelevant because it's always too soft to hear. It's a total non-issue.


Quote:
you think it matters cus teh pundits of bable in audio mags keep telling you it matters


This nails the problem. 30 years ago pro audio magazines were written by pros. Many of the articles were DIY projects written by people that actually know how to design circuits. And most of the reviews were serious and included not only vendor specs but independent tests made by the article author. This is one of the great things about Stereophile that is lacking in just about every magazine today, both consumer and pro. It kills me when a loudspeaker review includes the size of the woofer but no hint as to upper and lower 3 dB points. Off-axis response and distortion? Fuggedaboutit!

--Ethan

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
Your dismisal of jitter calling it a "non-issue" is still unsupported.


Usually when a thread degenerates into one person calling another "shit-for-brains" I'm out. But I still believe there's hope for you so I'll continue to be civil and try to help. I'm sure you're a great guy who would never talk like that face to face.

Dave, jitter is indeed a non-issue because all logic and common sense, and understanding audibility and the masking effect, clearly shows it's too soft to hear. According to Ken Pohlmann's Principles of Digital Audio, jitter is typically below -110 dB. This is way below the noise floor of a CD, which itself is well below the acoustic noise floor of most recordings. So all logic says jitter will be inaudible. Now, it may be that jitter is audible, but the burden of proof is on those who believe that.

Does this not make sense to you?

--Ethan

dcstep
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Re: Hearing stuff never heard before!

No, I talk like that face-to-face.

I hear differences in digital clocks. I don't know why, but jitter may be part of the reason. Your explanation is not convincing because you may not be addressing all the issues relevent to jitter. I don't know enough about the subject to argue with you about it, BUT I do know that you tend to take simplistic approaches and dismiss things with little support, so I remain undecided about the relevence of jitter.

Please notice that I've never said anywhere that jitter makes an audible difference. I'm only questioning your dismissal of its importance. Maybe someone that has actually worked with audio in the digital domain and knows something about jitter can chime in.

Dave

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Re: Hearing stuff never heard before!


Quote:

Quote:
Your dismisal of jitter calling it a "non-issue" is still unsupported.


Usually when a thread degenerates into one person calling another "shit-for-brains" I'm out. But I still believe there's hope for you so I'll continue to be civil and try to help. I'm sure you're a great guy who would never talk like that face to face.

Dave, jitter is indeed a non-issue because all logic and common sense, and understanding audibility and the masking effect, clearly shows it's too soft to hear. According to Ken Pohlmann's Principles of Digital Audio, jitter is typically below -110 dB. This is way below the noise floor of a CD, which itself is well below the acoustic noise floor of most recordings. So all logic says jitter will be inaudible. Now, it may be that jitter is audible, but the burden of proof is on those who believe that.

Does this not make sense to you?

--Ethan

I may be off here, but I seem to recall that when people were initially displeased by digital sound, a cause/effect analysis was done...and it lead to the discovery of jitter in players as a sonic problem, with jitter measurements correlating with sound quality.

Am I mis-remembering this situation?

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
No, I talk like that face-to-face.


LOL! At least you're honest.


Quote:
Your explanation is not convincing because you may not be addressing all the issues relevent to jitter.


What part of "110 dB below the noise floor" do you not understand?


Quote:
I do know that you tend to take simplistic approaches and dismiss things with little support


I do try to reduce things to what really matters, but I have lots of support. Did you read either of my articles I linked earlier, about the audibility of dither and jitter? They both include files you can download and listen to on your own system. At least I'm trying to get to the bottom of this stuff. Versus many people who, like you, admit they don't understand it well, but go on to voice strong opinions anyway. I'm all for strong opinions, but only when they're informed opinions!


Quote:
Maybe someone that has actually worked with audio in the digital domain and knows something about jitter can chime in.


Ken Pohlmann is a leading expert on digital audio and he has already chimed in. Here's an article about jitter by Bob Adams of Analog Devices that's not too technical:

http://www.theaudiocritic.com/back_issues/The_Audio_Critic_21_r.pdf

--Ethan

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Re: Hearing stuff never heard before!


Quote:
I seem to recall that when people were initially displeased by digital sound, a cause/effect analysis was done...and it lead to the discovery of jitter in players as a sonic problem, with jitter measurements correlating with sound quality.


I'm not aware of any compelling evidence of jitter being audible at all, let alone audible to the point of harming the music. That is, a small amount of tape hiss is audible (not to mention vinyl surface noise) but that doesn't seem to bother devotees. Regardless, you're probably remembering correctly, but what you read was likely misinformed opinion and/or guesses by magazine writers. That's not the same as hard proof.

My best guess for why early digital was shunned by some is due to using master tapes that were intended for a vinyl lathe. Vinyl requires HF boost that is reduced upon playback, so that could account for a perceived harsh sound if the same tape is used for CD. I always thought early CDs sounded very good, especially compared to vinyl and cassettes at the time. There may be some CDs that sounded terrible. I know only the CDs I own, which is maybe 0.000001 percent of all CDs out there.

Buddha, what did you think of CDs when they first came out?

--Ethan

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Re: Hearing stuff never heard before!


Quote:
... -110 dB. This is way below the noise floor of a CD, which itself is well below the acoustic noise floor of most recordings.

-110dB is far below the noise floor of any recording.

The sonic difference between a USB input to a DAC and an S/PDIF input is often apparent. If jitter is not the cause of the sound difference, what is?

I've heard this difference and can readily point it out on certain recordings. Many reviewers have commented on this also.

Buddha
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Re: Hearing stuff never heard before!


Quote:

Buddha, what did you think of CDs when they first came out?

--Ethan

First one I ever heard was a Streisand disc at the local Hi Fi shop on that first Sony CDP-101 player.

Other than not liking Streisand, I vividly recall that out of the silence at the start of the disc, hearing a HUGE inhalation from Streisand that was obviously overlooked in the remaster.

Hhhhhhuuuuuuuuuuuuuh, then she started to sing.

We listened on some A/D/S 810's and Acoustat 2+2's (biege).

It was at Q Audio in Reno, NV, and Ollie was the salesman.

The sound was bright, and probably 'detailed' due to a high frequency over-emphasis (the mixing, as you mention.)

I think we also tried listening to some Springsteen, but Clarence Clemons'sax sounded awful.

I was put off by the audition, and did not buy a CD player until I got a Sony ES something in late 1988.

I like CD OK, it does seem a little "gynecologic" to me, still, but I buy 'em and play 'em.

I think CD still has problems. It seems a bit etched, to my ears, with emphasis on detail that just stops at some point. It sounds 'clear' right up until it seems to convey a sense of "no more data available."

These things are hard to describe. Maybe a good analogy would be that CD sounds like animation looks - vivid right up until the point where there is no more information to be had.

dcstep
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Re: Hearing stuff never heard before!

Not surprisingly, the cited articles (thanks for the lead Ethan) don't cover all the facts. For instance, audibility may be -110dB below 100hz, but rises 6db per octave thereafter. See Robert Dunn's AES paper, particularly graph #9 for the audibility chart (heard as a hardness in the sound). The Dunn article dates back to the article Ehan cited. Here are some recent articles that are a decade or two more recent:

http://www.tnt-audio.com/clinica/jitter2_e.html
http://www.nanophon.com/audio/1394_sampling_jitter.pdf
http://www.nanophon.com/audio/diagnose.pdf

People seem to continue to work very hard at this issue for something that has no audible impact. I wonder what gives??? I'm surprised that all these engineers are presenting to the AES for marketing purpose.

Oh, BTW, I've been reading and distrusting Audio Critic since 1976. It's a good read for a different perspective from TAS and Stereophile, but I recommend not taking anything that Peter says or publishes as gospel. Aczel, as usual, was too busy sniping at Robert Harley to cite other articles that more directly addressed audibility.

Dave

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Re: Hearing stuff never heard before!

Ethan,

You appear to be regarding the effect of jitter as creating a sound separate to the music that is far too low level to be heard. I don't think that is the impact that it has:

A DAC is reading digital values and creating an analogue signal from those values. The assumption is that the rate that the digital values arrive at the DAC is identical to the rate at which they were recorded. If the rate that those digital values arrive for conversion differs slightly from the original rate or is not constant then the analogue signal created will be different from the one recorded. This would imply that the more stable and accurate the clock controlling the arrival of samples at the DAC the more faithful the analogue output will be to the original analogue signal.

I didn't think this would make a big difference in the sound until I connected the word clock output from my sound card to my upsampler/DAC and noticed that the sound improved. This change provided the clock from the sound card direct to DAC instead of it being transmitted across the SPDIF interface with the data.

In the link that you graciously provided to the Dan Lavry interview in another thread he talks a lot about the effect of jitter and finishes with "Unlike tube, transformer or many other distortions, the outcome due to jitter is NOT predictable or repeatable. There is no such thing as

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
-110dB is far below the noise floor of any recording.


No kidding.


Quote:
The sonic difference between a USB input to a DAC and an S/PDIF input is often apparent. If jitter is not the cause of the sound difference, what is?


Very brief drop-outs? Computers that are not optimized for audio (too many background services etc) can suffer millisecond drop-outs.

I'm more than a little skeptical that one steady digital stream can sound different than another through the same gear and speakers. And jitter definitely manifests as side-band noise. As soon as someone says they heard a change in low-end fullness, or high end, or stereo imaging, I know what they really hear is comb filtering. Jitter cannot possibly change the frequency response or imaging - it's a teensy amount of noise! So with that in mind, how do you describe the difference between SPDIF and USB?


Quote:
I've heard this difference and can readily point it out on certain recordings. Many reviewers have commented on this also.


Please clarify. You mean to say you can readily identify USB versus SPDIF on some recordings better than on others? And of course you can do this blind, yes?

--Ethan

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Re: Hearing stuff never heard before!


Quote:
Not surprisingly, the cited articles (thanks for the lead Ethan) don't cover all the facts. For instance, audibility may be -110dB below 100hz, but rises 6db per octave thereafter. See Robert Dunn's AES paper


That paper is from 1992. These days even $20 sound cards have jitter so low it has to be predicted. In fact, the graphs in that article also are all predicted and calculated. As I recall, when you asked when jitter ceased to be an issue I said about 20 years ago. I doubt jitter was audible even in 1992. In fact, I really doubt it was ever audible. The only serious engineers that claim jitter is an issue today are those that sell expensive A/D/A converters.

But those engineers are correct. Bad jitter - like 100 times worse than a $20 sound card - probably could be a problem.

Also, I didn't see anything showing 6 dB per octave increase. The graphs on that article show jitter never being higher than -96 dB, which is at the CD's 16-bit noise floor.


Quote:
particularly graph #9 for the audibility chart (heard as a hardness in the sound)


I don't see that graph, nor do I find the word "hardness" anywhere in the article.


Quote:
http://www.tnt-audio.com/clinica/jitter2_e.html


Yes, a more modern article - the graphs in that article show jitter being 140 dB down!

Just because something can be measured, or predicted, does not mean it's audible or a problem. Please keep this in context. Vinyl has a surface noise about 30 to 50 dB below the music, with occasional crackles and ticks louder than the music. Yet jitter and digital audio generally are perceived as not hi-fi?


Quote:
People seem to continue to work very hard at this issue for something that has no audible impact.


Specmanship.


Quote:
I'm surprised that all these engineers are presenting to the AES for marketing purpose.


That, and mental masturbation.

--Ethan

dcstep
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Re: Hearing stuff never heard before!

Down -140dB at 100hz, but rising at over 6dB per octave. I cited the old 1992 article to show what was left out of the 1994 article that you cited. The 2000 article that I posted is still talking about audible jitter.

What else have you failed to tell us in your misleading posts? I see no evidence that the issue of jitter is settled at all. Since I'm not a digital designer I'm not going to conduct my own experiments or do further research, but my little foray into researching your "challenge" to me convinces me that plenty of learned people still consider it an issue and are expending real effort dealing with it. Your dismissal was clearly premature.

Your mother should be happy that I answer her son's silly challenge.

Dave

ethanwiner
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Re: Hearing stuff never heard before!


Quote:
You appear to be regarding the effect of jitter as creating a sound separate to the music that is far too low level to be heard.


Yes, that's exactly what it is, and every graph of jitter you'll find anywhere expresses it as noise side-bands some number of dB below the signal.


Quote:
I didn't think this would make a big difference in the sound until I connected the word clock output from my sound card to my upsampler/DAC and noticed that the sound improved.


Are you sure it got better and not worse? I doubt the sound changed at all, but let's assume you're correct and can pick out one clock from another blind every time. According to all the posts I see from Dan Lavry, external clocks can only make jitter worse:

http://recforums.prosoundweb.com/index.php/mv/msg/10086/136316/0/#msg_136316

Note that I do want to have it both ways by quoting Dan on the science, while disagreeing that low jitter sounds better. As I said above, it's a game of specsmanship where there's a need to convince people to spend $2,000 for a small electronic device. Just like an amp maker claiming 0.0002 percent distortion when even 0.01 percent is inaudible. Yes, I want to buy gear with the best specs too. If not because it sounds better, at least because it shows that the designer engineers know what they're doing. Meaning it's less likely to oscillate, will probably run cooler and last longer, etc.


Quote:
finishes with "Unlike tube, transformer or many other distortions, the outcome due to jitter is NOT predictable or repeatable.


Right, it's random noise. Like tape hiss. Only a hell of a lot softer!

--Ethan

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Re: Hearing stuff never heard before!


Quote:
Down -140dB at 100hz, but rising at over 6dB per octave.


Even if that's true, it's still below the noise floor!

Jim Tavegia
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Re: Hearing stuff never heard before!

I fully agree...the jitter issue is not fully put to rest and that is why JA measures every digital device that comes his way. Should we have assumed that the $6500 Mac Music Server is as good a DA as a $20 sound card? Hardy, as JA found out. Certainly JA is not going to waste his valuable time measuring low grade consumer computer sound cards. Didn't the high priced Zanden have high jitter as well?

If you have a digital device and you have to add a Benchmark DAC to it to make it a class A or B Stereophile kit, I am not sure you can call it high end audio. We should at least be at that point of agreement.

We still have so far to go with in-room speaker response, phase accuracy, and efficiency that it seems arguing over jitter way less important, but that does not mean it is not an issue. Those of you with excellent hearing, I feel confident, can hear the difference between a very good CD player and one full of jitter.

dcstep
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Re: Hearing stuff never heard before!

BTW, people actually hear below the noise floor. Just listen to an LP to hear for yourself.

Dave

Elk
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Re: Hearing stuff never heard before!


Quote:

Quote:
The sonic difference between a USB input to a DAC and an S/PDIF input is often apparent. If jitter is not the cause of the sound difference, what is?


Very brief drop-outs? Computers that are not optimized for audio (too many background services etc) can suffer millisecond drop-outs.


I am sure this is not it, both because my primary desktop is indeed optimized for audio and is ridiculously powerful. Even high resolution multi-channel audio is not much of a challenge for a modern high-end work station.

Plus drop outs are easy to measure/see in a waveform - as you of course know.


Quote:
I'm more than a little skeptical that one steady digital stream can sound different than another through the same gear and speakers.


Me, too.


Quote:
You mean to say you can readily identify USB versus SPDIF on some recordings better than on others? And of course you can do this blind, yes?


Yes, some instruments are easier to hear differences just like piano is great for hearing wow and flutter in a tape drive or TT.

I am quite sure I could hear it blind, but haven't checked. I don't have any vested interest as the DAC easily switches between USB, optical s/pdif, coax s/pdif, AES. All are connected simply because I can.

USB is different than the others. Jitter measures much higher as well. Of course, this could be coincidence.

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Re: Hearing stuff never heard before!


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...jitter is indeed a non-issue because all logic and common sense, and understanding audibility and the masking effect, clearly shows it's too soft to hear. According to Ken Pohlmann's Principles of Digital Audio, jitter is typically below -110 dB... --Ethan

Ethan,
You may want to re-read your references.

From the reference you give:
http://www.mcgoodwin.net/digitalaudio/digitalaudio.html

Quote:
Any variation in absolute timing comprises "jitter", which adds noise and distortion. Jitter is worst for high amplitude high frequency signals. Jitter must be less than 200 ps (picoseconds) for 16 bit sampling of a 20 kHz full amplitude sinewave and less than 100 ps for 20 bit in order to keep resultant noise below the quantization noise floor

Most digital gear come nowhere near that ideal "absolute timing".

Which brings into question; which kind of jitter are you referring to?

It is important to distinguish between the MANY different types of jitter.

See this for more info:
http://www.tnt-audio.com/clinica/jitter1_e.html

Here is an example; Low-frequency correlated phase jitter, is otherwise known as wow and flutter. This type can NOT be quantified in terms of db. However, listen to a piano track on any 'run-of-the-mill' tape machine and one can readily hear what kind of negative effects this particular type has.

This warble effect is more subtle in the digital realm and tends to manifest itself as smeared highs not out-of-band noise (the result of the type of jitter you seem to be referring to).

Jitter ratings (all specs really) in and of themselves are meaningless, much like S/N ratio or even watts. They have to be considered in the context to which they apply and relative to other factors. They CAN be a good indication of quality but you still need to go and listen.

When it comes to audio gear the gestalt principal applies. This means that the whole is indeed greater than the sum of its parts (or even its specs). All of us value different aspects differently. Specs will NEVER answer the value proposition question in a universal way (IMO, YMMV, etc...).

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Re: Hearing stuff never heard before!


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BTW, people actually hear below the noise floor. Just listen to an LP to hear for yourself.


Agreed, but not when the noise floor is already at -90+ dB unless you raise the volume to be unnaturally loud.

--Ethan

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Re: Hearing stuff never heard before!


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USB is different than the others. Jitter measures much higher as well. Of course, this could be coincidence.


Any way you can record or capture this to a pair of Wave files?

--Ethan

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Re: Hearing stuff never heard before!


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Jitter must be less than 200 ps (picoseconds) for 16 bit sampling of a 20 kHz full amplitude sinewave and less than 100 ps for 20 bit in order to keep resultant noise below the quantization noise floor


In Figure 4.20 of Pohlmann's book the noise spectrum of 2 ns jitter is shown as being below -110 dB. So that's ten times more jitter than 200 picoseconds, yet the noise is still well below the noise floor of the CD. There's a difference between engineering design goals (make the circuit as good as possible) and practicality of what is actually audible. In my Artifact Audibility Report there are Wave files to download having noise much higher than that, and most people will be hard pressed to hear it. This is what really matters. IMO people obsess over all the wrong things.


Quote:
which kind of jitter are you referring to?


Clock jitter, not wow and flutter. Though wow and flutter are a type of jitter too, as you observed.

--Ethan

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Re: Hearing stuff never heard before!


Quote:

Quote:
USB is different than the others. Jitter measures much higher as well. Of course, this could be coincidence.


Any way you can record or capture this to a pair of Wave files?


You know I could, BWF to be exact. I should have thought of this already. Perhaps this weekend.

Good thinking.

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Re: Hearing stuff never heard before!


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Perhaps this weekend.


Excellent. Do you have a way to easily null Wave files? If not, or even if you do, please send them to me so I can do that here. Either short excerpts by email, or a CDR to the address on the RealTraps site.

--Ethan

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Re: Hearing stuff never heard before!

I have the latest version of SoundForge, which I know that you use as well.

I understand that we need to flip the waveform of one of the recordings and sum it with the other, but can you easily describe the process you use?

Oddly enough, I just use the program for mastering.

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Re: Hearing stuff never heard before!

I do null tests in SONAR because it's easier to align both files in time horizontally, and you can also adjust the volumes separately. It can be done in Sound Forge, but it's easiest if the files start at the exact same place and are the exact same volume. In that case copy one file, then do Edit .. Paste Special .. Mix into the other checking the box to flip either file's polarity.

--Ethan

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Re: Hearing stuff never heard before!

This is what I was coming up with, recording the same bit of a file, such as creating a 15 second file of music to play. This would make it easy to make sure the files are the same. As SoundForge will handle multichannel it should be easy to get them lined up and looking the same before putting them together.

I actually have a copy of Sonar that I have not played with in a long time (I rarely have any need for multi-tracking). I'll take a look at it as well.

Lamont Sanford
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Re: Hearing stuff never heard before!

Can't I just turn the volume up or down?

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Re: Hearing stuff never heard before!


Quote:
As SoundForge will handle multichannel it should be easy to get them lined up and looking the same before putting them together.


Right, I forgot they added that feature. I'm still on SF version 6 because it does everything I need and Sony has enough of my money.

--Ethan

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Re: Hearing stuff never heard before!

http://www.libinst.com/Audio%20DiffMaker.htm

thats all you need.

man, some audiophile nutjobs get all bent out of shape when you start throwing science and logic at them... science and logic do not belong in the realm of the audiophile It is a world dominated by hocus pocus, gear envy, voodoo, and snake oil... a 50,000 "transport" (that is a particularly funny term) must be better than a 2,000.00 one by default..quality is also in direct relation to the number of audiophile bs buzzwords smattered in the review article.

Ive got a nice system too,(although my speakers arent from audiophilia land, but studio realm(ATC and ProAC/bryston/quad) but jeesh, some of these people..

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