Re: Urban Myths...
And here's the most telling excerpt...
*****
Myth 5: 16 bits are not enough
PO: ‘Quantization is bad’ nonsense
RP: Converters are available with more than 16
bits, so why not?
ST: The dynamic range of the human ear is
greater than 16 bits
TM: 24-bit DVD-Audio
RT: 16 bits gives 98 dB dynamic range; typical
home system can achieve 60 dB; CD noise floor
can be as low as 19 bits perceptually; 20 bits is
great for studio mastering but not needed in a
delivery medium
*****
I believe none of us have a typical home system of only 60dB dynamic range. Well, that's not true... I have a couple of boom-boxes lying around.
ensen.
Tube_Dude said:Hi Guys!
A nice reading!!
http://signal.ece.utexas.edu/seminars/dsp_seminars/01fall/AudioMyths.pdf
Cheers!
And here's the most telling excerpt...
*****
Myth 5: 16 bits are not enough
PO: ‘Quantization is bad’ nonsense
RP: Converters are available with more than 16
bits, so why not?
ST: The dynamic range of the human ear is
greater than 16 bits
TM: 24-bit DVD-Audio
RT: 16 bits gives 98 dB dynamic range; typical
home system can achieve 60 dB; CD noise floor
can be as low as 19 bits perceptually; 20 bits is
great for studio mastering but not needed in a
delivery medium
*****
I believe none of us have a typical home system of only 60dB dynamic range. Well, that's not true... I have a couple of boom-boxes lying around.
ensen.
How to think critically, 101
how about these lines:
=========================================
usually the folks with the wild claims are trying to sell you something;
burden of proof is on those making claims;
anecdotal evidence is not evidence at all;
subjective tests not done double-blind are probably worthless;
physics, electronics and materials science well understood;
quantitative data is important.
=========================================
Enjoy.
Tube_Dude said:
how about these lines:
=========================================
usually the folks with the wild claims are trying to sell you something;
burden of proof is on those making claims;
anecdotal evidence is not evidence at all;
subjective tests not done double-blind are probably worthless;
physics, electronics and materials science well understood;
quantitative data is important.
=========================================
Enjoy.
Aw, Nelson, you're just upset because he kicks you in the wallet on page 11. And you managed to return the favor in your usual genial manner. Well done!
enson: Most analog systems are lucky to get a 60 dB S/N. And frankly, unless you've got a dedicated room, no wife or kids, and extensive wall treatment and soundproofing, you're probably not doing too much better than 40 dBa as ambient noise. So, it's more than cheap boom boxes...
enson: Most analog systems are lucky to get a 60 dB S/N. And frankly, unless you've got a dedicated room, no wife or kids, and extensive wall treatment and soundproofing, you're probably not doing too much better than 40 dBa as ambient noise. So, it's more than cheap boom boxes...
SY said:
enson: Most analog systems are lucky to get a 60 dB S/N. And frankly, unless you've got a dedicated room, no wife or kids, and extensive wall treatment and soundproofing, you're probably not doing too much better than 40 dBa as ambient noise. So, it's more than cheap boom boxes...
And no noisy neighbours
Dynamics folks... not SNR, although there are many pre/amp combos that give can you >80dB SNR. Besides, even with lots of ambient noise, it's possible to distinguish if the sound comes from outside, next door or the speakers.
Really $20,000 - that sure is a load of money for something that only needs to give 60dB. Maybe they use the tried and true uA741 in their buffers since they don't need better than 60dB. Yuk! At least my money is being spent on stuff good enough that I can no longer tell that it's crap.
One more thing... is that dBa, dBV, dBU, dB@1W/m, dB@2.83V/m, etc., etc., etc.? Does dB stand for double Blind, or what?
ensen.
Really $20,000 - that sure is a load of money for something that only needs to give 60dB. Maybe they use the tried and true uA741 in their buffers since they don't need better than 60dB. Yuk! At least my money is being spent on stuff good enough that I can no longer tell that it's crap.
One more thing... is that dBa, dBV, dBU, dB@1W/m, dB@2.83V/m, etc., etc., etc.? Does dB stand for double Blind, or what?
ensen.
sss said:i dont know how u people can claim that u can hear differences between op amps like opa627 , ne5532 , opa134 and so on ....?
wasn't there a film called "dead men talking?" or something like that.
I'd say it's "interesting"....john curl said:That TI "AUDIO MYTH" paper is complete garbage. It is an insult to the engineering community.
Proof = true, No proof = untrue
How easy it would be if the world was that way.
Re: lmh6715 vs. tl082
...
If you want to do a serious test, at least listen to the same opamp on both channels... such that you switch between 2xlmh or 2xtl082. Listening in mono is only half the truth, and has nothing to do with "real-world" sound anymore.
Now, not only do you have different tyres on each side of your test car, but you are running your test with a Wartburg
Furthermore, you're only making left turns, because that's the way your track goes round. Now tell me which tyre should I buy for my BMW?
You should at least get some proper headphones. AND do a test in a proper stereo setup - headphones are nice and good at details, but not for soundstage etc.
Well if the test person was completely blinded (so as to avoid bias), this test (using two pairs of opamps, good phones AND a speaker setup) might be OK. Provided that the test person took his time listening to whole music passages, before deciding whether opamp A or B was playing.
Unfortunately, I don't think it's possible for anyone to carry out the test him/herself without bias
But I read you were improving - is your hearing getting better?
Happy to hear that there are great people in here who still have their heads affixed correctly, and know that audio-myth thing is a load of crap written by some total ignorant (or maybe just someone deaf?).
cheers,
Cdl
Allright, let's accept that circuit setup for now for the sake of comparisonmillwood said:put together two headphone amps using lmh6715 and good old tl082. they both follow the headphone amp schematic in the opa227 datasheet.
...
Kind of like testing tires for a car, using the Goodyear on one side, and Michelin on the other...
I fed both channels the same signal (one channel split to go to both opamps) and couldn't tell if the earbuds (L and R) were swapped (I was right 9 out of 24 times. I will try a few more rounds tomorrow).
If you want to do a serious test, at least listen to the same opamp on both channels... such that you switch between 2xlmh or 2xtl082. Listening in mono is only half the truth, and has nothing to do with "real-world" sound anymore.
....the earbuds are the ones for ipot and a panasonic cheapo pair.
Now, not only do you have different tyres on each side of your test car, but you are running your test with a Wartburg
Furthermore, you're only making left turns, because that's the way your track goes round. Now tell me which tyre should I buy for my BMW?
You should at least get some proper headphones. AND do a test in a proper stereo setup - headphones are nice and good at details, but not for soundstage etc.
this might be a good experiment to try since if you cannot hear a difference between opamps driving earbuds, you are unlikely to have heared their difference in less demanding applications.
Well if the test person was completely blinded (so as to avoid bias), this test (using two pairs of opamps, good phones AND a speaker setup) might be OK. Provided that the test person took his time listening to whole music passages, before deciding whether opamp A or B was playing.
Unfortunately, I don't think it's possible for anyone to carry out the test him/herself without bias
But I read you were improving - is your hearing getting better?
Happy to hear that there are great people in here who still have their heads affixed correctly, and know that audio-myth thing is a load of crap written by some total ignorant (or maybe just someone deaf?).
cheers,
Cdl
Piece of Crap
I agree 100% John. This article I consider a provocative piece of crap.
john curl said:That TI "AUDIO MYTH" paper is complete garbage. It is an insult to the engineering community.
I agree 100% John. This article I consider a provocative piece of crap.
Re: Piece of Crap
I like the part about vinyl and 40 bits
I think many parts are not crap but the attitude isn't very humble.Elso Kwak said:
I agree 100% John. This article I consider a provocative piece of crap.
I like the part about vinyl and 40 bits
Well, since most of that 'paper' is "bald assertion or anecdote" complete with ad hominem attacks, I don't think a full rebuttal is worth anyone's time, and a partial one probably wouldn't do justice to any other viewpoint than that of the article's. Even said document says, "Burden of proof is on those making claims". This document makes lots of claims, passing them off as the "Real Truth". If it were even the partial truth it would at least consider things like jitter and distortion spectra (to name but two).
First one should observe that Tom Kites paper seems to be
a set of slides. Hence, it is by necessity very brief and makes
claims without justifying them. In this respect it is no better
than the audio myths it is attacking. It is claim against claim.
I have at least two immediate counterarguments.
Dynamics over 100dB has been measured in real concerts, so
for those who want to recreate a real concert at home, 98dB
might not be sufficient. There remains to be recordings found
that provide such extreme dynamics, though.
If power supplies are not important for well-designed amplifiers,
then how come that non-audio companies like Analog Devices
stress the importance of power supplies? Tom Kite even
says in his slides that they are competent op amp designers!!!
a set of slides. Hence, it is by necessity very brief and makes
claims without justifying them. In this respect it is no better
than the audio myths it is attacking. It is claim against claim.
I have at least two immediate counterarguments.
Dynamics over 100dB has been measured in real concerts, so
for those who want to recreate a real concert at home, 98dB
might not be sufficient. There remains to be recordings found
that provide such extreme dynamics, though.
If power supplies are not important for well-designed amplifiers,
then how come that non-audio companies like Analog Devices
stress the importance of power supplies? Tom Kite even
says in his slides that they are competent op amp designers!!!
purplepeople said:Hi millwood
How's the testing going? Are you better than 50% yet?
ensen.
haven't done any. I didn't leave my office until about 3am this morning and at 8am I am back.
I have found that I have a better chance if I just guess it blind,
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