Hello,
I believe it is generally believed here that a $150 dac is transparent. Where are the tests to show this? Yes, I could conduct the test for myself and see if I pass or fail, but I'm looking more for a larger scale testing to see if other people can pass or fail it, rather than just myself.
Thanks.
This article might be interesting to you:
http://www.tomshardware.com/reviews/high-e...audio,3733.html (http://www.tomshardware.com/reviews/high-end-pc-audio,3733.html)
This article might be interesting to you:
http://www.tomshardware.com/reviews/high-e...audio,3733.html (http://www.tomshardware.com/reviews/high-end-pc-audio,3733.html)
I think their conclusion goes a BIT too far. The 77 ohm output impedance of the Realtek should be easily audible with certain headphones. Of course, that's more of a headphone amplifier comparison, not a DAC comparison. Actually, it might increase the bass output of the HD800's enough to be audible. I certainly notice the difference with a 120 ohm output, but I don't know if I'd hear 77ohms.
I'm looking more for a larger scale testing to see if other people can pass or fail it, rather than just myself.
Who do you have in mind?
Trying to "convert" audiophools to a more rigorously scientific approach is a waste of time IMO. For them, the notion that perfect fidelity could be inexpensive and even available from the likes of Target stores is simply not an acceptable reality. Too much ego/self-worth issues on the line I think.
This article might be interesting to you:
http://www.tomshardware.com/reviews/high-e...audio,3733.html (http://www.tomshardware.com/reviews/high-end-pc-audio,3733.html)
I think their conclusion goes a BIT too far. The 77 ohm output impedance of the Realtek should be easily audible with certain headphones. Of course, that's more of a headphone amplifier comparison, not a DAC comparison.
Yeah, the headphone amp is obviously crap at 77 ohms, but its not really made to drive headphones, and the DAC is fine for powered speakers.
This article might be interesting to you:
http://www.tomshardware.com/reviews/high-e...audio,3733.html (http://www.tomshardware.com/reviews/high-end-pc-audio,3733.html)
I think their conclusion goes a BIT too far. The 77 ohm output impedance of the Realtek should be easily audible with certain headphones. Of course, that's more of a headphone amplifier comparison, not a DAC comparison.
Yeah, the headphone amp is obviously crap at 77 ohms, but its not really made to drive headphones, and the DAC is fine for powered speakers.
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
Thanks for the replies guys. However, I was hoping for something of a larger scale. For example, when we do drug trials or crime statistics, we look for a much larger sample size than 2 people. I understand that doing thousands upon thousands tests like this will be impractical but I was hoping for maybe a test of 10, 20, 30, 40, 50 people.
Thanks for the replies guys. However, I was hoping for something of a larger scale. For example, when we do drug trials or crime statistics, we look for a much larger sample size than 2 people. I understand that doing thousands upon thousands tests like this will be impractical but I was hoping for maybe a test of 10, 20, 30, 40, 50 people.
You can't extrapolate from bench measurements + known limits of human hearing?
Do your own experiments if that's insufficient. Because who, exactly, is going to perform (and pay for) the experiments you require? DAC makers? Why would they?
Thanks for the replies guys. However, I was hoping for something of a larger scale. For example, when we do drug trials or crime statistics, we look for a much larger sample size than 2 people. I understand that doing thousands upon thousands tests like this will be impractical but I was hoping for maybe a test of 10, 20, 30, 40, 50 people.
You can't extrapolate from bench measurements + known limits of human hearing?
Do your own experiments if that's insufficient. Because who, exactly, is going to perform (and pay for) the experiments you require? DAC makers? Why would they?
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
Test only 50 people? But what if the 51st one, you didn't test, could hear a difference?
Even if you tested all 7 billion humans on Earth, at the moment, how would you know that the headphones/stereo you used were adequate or that the song selection was good enough? Audiophools will never be satisfied and will always challenge any results using this methodology with their three, classic, perpetual excuses:
- you tested the wrong people
- you used inadequate peripheral gear
- your musical selections were inadequate
This is why when I challenged my Stereophool reading audiophile friend I had the foresight [pre Meyer and Moran, I might add] to make the challenge "I bet YOU can't hear a difference, and that includes under any conditions of your choice, using any gear you can get a hold of [turned out to be a >$13K, hand selected 2ch system entirely of his choice, in a dedicated, professionally designed sound room with extensive acoustical room treatments, not someone's living room], using any music of your choice, at your chosen pace, any time, any place." He lost. [But our test was of amps].
Your "test 50 people" approach is like trying to convince followers of Uri Geller that he can't bend spoons with his mental powers because these 50 random people you tested can't. It won't get you anywhere with his devotees.
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
It would be nonsensical to do a large scale study to answer the question whether $150 DACs are sonically transparent. The question itself is the problem. What would you choose as a representative example of such a DAC? Or would you want to test all of them? What kind of difference is it that you want to test the audibility of? Noise floor? Distortion? Frequency response? Phase response? Something else entirely? Undefined and usually meaningless properties like "musicality"?
A large scale study needs a well-defined and sensible research hypothesis, not a broadly worded question.
Thanks for the replies guys. However, I was hoping for something of a larger scale. For example, when we do drug trials or crime statistics, we look for a much larger sample size than 2 people. I understand that doing thousands upon thousands tests like this will be impractical but I was hoping for maybe a test of 10, 20, 30, 40, 50 people.
You can't extrapolate from bench measurements + known limits of human hearing?
Do your own experiments if that's insufficient. Because who, exactly, is going to perform (and pay for) the experiments you require? DAC makers? Why would they?
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
You seem to have ignored my first (rhetorical) question.
But at least now we have a better idea of the axe you're intending to grind.
Hello,
I believe it is generally believed here that a $150 dac is transparent.
Don't speak for anyone/all else, but I can see most DACs, including $150 ones. Perhaps you mean "audibly indistinguishable vs other non-pathological DACs"? Then yes, $150 should do, unless shown otherwise.
Where are the tests to show this?
Show what? You've got the cart before the horse. You need only one example that violates the premise. Got one?
Yes, I could conduct the test for myself and see if I pass or fail, but I'm looking more for a larger scale testing to see if other people can pass or fail it, rather than just myself.
Thanks.
Why?
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
What is this in reference to?
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
This doesn't really make sense. You can't determine the abilities of people to discern a difference in general by testing specific devices, so this huge test you're hoping for would be useless for your purposes. You can do that by controlled listening tests that measure the threshold of audibility for different audio phenomena. If you want to understand the physics of human hearing, I'd ignore device tests entirely and start reading up on the scientific literature.
The only thing testing specific devices can really do is show you that theres not very much difference between devices, but probably you already knew that.
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
To what end? I don't think the notion of transparency from a $150 DAC such as ODAC is controversial on HA or the public at large, just a tiny subset of the population which isn't likely to accept the validity of controlled testing procedures anyhow.
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
Let's flip this on its head.
The assumption is that DACs such as the ODAC perform the task of converting digital recordings to analog signals with no audible defects or noise. It can be inferred from measurements that neither THD, stereo crosstalk, noise floor or any other parameter reaches audible levels, by a margin that is quite large.
The question should not be "can you prove that there are no audible defects", because the measurements quite clearly show that there are indeed no audible defects.
Rather, the question and burden of proof is on those who believe these measurements are wrong, and that there are indeed audible defects present when using high-quality DACs such as the ODAC. So far, no one has been able to provide any proof for these arguments, other than audiophile woo-woo. At least not in any case I know of where the measurements didn't already indicate a problem.
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
As others have pointed out, the quick summary of all generally accepted scientific evidence to date is that a DAC that measures as good as the ODAC can reasonably be expected to be totally undetectable by any human being, and not by a little.
To be more specific, the ODAC should be able to pass a straight wire bypass test, hands down.
A product that measured say 10 times worse can be reasonably be expected to pass the same tests.
100 times worse, probably that too.
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
To be more specific, the ODAC should be able to pass a straight wire bypass test, hands down.
How would one do a straight wire bypass test with a DAC?
To be more specific, the ODAC should be able to pass a straight wire bypass test, hands down.
How would one do a straight wire bypass test with a DAC?
Obviously, an ADC needs to be added to the test setup.
This puts the ODAC at the mercy of the quality of added ADC, but finding adequately high performing ADCs is not rocket science.
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
Which means that there may or may not be a problem.
The fact that computer noise is another 20 dB down in most cases often effectively addresses that concern.
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
Which means that there may or may not be a problem.
The fact that computer noise is another 20 dB down in most cases often effectively addresses that concern.
I don't know how you established "in most cases," but I'm planning to check my motherboard grounding...
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
Which means that there may or may not be a problem.
The fact that computer noise is another 20 dB down in most cases often effectively addresses that concern.
I don't know how you established "in most cases,"
Over 20 years experience measuring and liotsening.
but I'm planning to check my motherboard grounding...
May help if not done right the first time.
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
Which page exactly are you getting those numbers from?
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
Which page exactly are you getting those numbers from?
My own testing with an ALC889
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
Which means that there may or may not be a problem.
The fact that computer noise is another 20 dB down in most cases often effectively addresses that concern.
I don't know how you established "in most cases,"
Over 20 years experience measuring and liotsening.
but I'm planning to check my motherboard grounding...
May help if not done right the first time.
I checked motherboard connections and tightened screws... Any other ideas?
This is not even 16-bit performance, and the computer is practically idling:
https://onedrive.live.com/redir?resid=5B2A7...int=photo%2cPNG (https://onedrive.live.com/redir?resid=5B2A74A081A41676!107183&authkey=!ALcaS70VYIflf1o&v=3&ithint=photo%2cPNG)
I checked motherboard connections and tightened screws... Any other ideas?
This is not even 16-bit performance, and the computer is practically idling:
https://onedrive.live.com/redir?resid=5B2A7...int=photo%2cPNG (https://onedrive.live.com/redir?resid=5B2A74A081A41676!107183&authkey=!ALcaS70VYIflf1o&v=3&ithint=photo%2cPNG)
Is this a self-loop using the onboard ADC? I know you have a Tascam interface in previous posts, try to switch the gain to GUITAR, turn the gain knob to compensate level differences and run the test in 24-bit again.
My VIA HD audio tests have much better results (recorded by X-Fi Titanium HD)
http://www.hydrogenaud.io/forums/index.php...ost&id=7804 (http://www.hydrogenaud.io/forums/index.php?act=attach&type=post&id=7804)
What did you use as your A/D converter?
I checked motherboard connections and tightened screws... Any other ideas?
This is not even 16-bit performance, and the computer is practically idling:
https://onedrive.live.com/redir?resid=5B2A7...int=photo%2cPNG (https://onedrive.live.com/redir?resid=5B2A74A081A41676!107183&authkey=!ALcaS70VYIflf1o&v=3&ithint=photo%2cPNG)
Is this a self-loop using the onboard ADC? I know you have a Tascam interface in previous posts, try to switch the gain to GUITAR, turn the gain knob to compensate level differences and run the test in 24-bit again.
My VIA HD audio tests have much better results.
http://www.hydrogenaud.io/forums/index.php...ost&id=7804 (http://www.hydrogenaud.io/forums/index.php?act=attach&type=post&id=7804)
You beat me by a minute!
One of the greatest contributions from RMAA to consumer audio world is that manufacturers are forced to use excellent ADCs even for $100 soundcards.
You're still going to get background noise as high as -80dB or higher, which could be audible at high volume during silent passages.
As a rule, the noise floor of almost all commercial recordings is -70 dB or higher. There are a few exceptions.
The source of the noise is typically "room tone" in the recording studio or venue where the recording was made, and that usually turns out to be spectrally shaped so as to put a lot of the noise at frequencies where the ear is not particularly sensitive.
Computer noise is not shaped to those standards.
Which page exactly are you getting those numbers from?
I presume that the -80 dB number comes from spec sheets and actual tests of audio interfaces and players. IME, most of the current crop of on-board audio interfaces are about 10 dB or more better.
My -70 dB number comes from analysis of a large number of commercial recordings. A recording with this low of a noise floor would likely be very dynamic and uncompressed. For the longest time my benchmark for this number was Rickie Lee James eponymous album and its still a good number for a pop album. Most recordings are at least 10 dB worse. Highly compressed recordings are going to be far worse.
There is a real issue here which is differences in the spectral content of the noise floors of digital gear, and that of real-world recordings. There is Fielder's classic JAES paper which has information for some of the finest recording venues in the world, which are generally in a class by themselves. That paper does not seem to represent actual working situations, even for work that is done in them. The noise floor of an world class empty room in the dead of the night is not representative of what they are like with 100 musicians playing their instruments in it in the middle of a normal working day.
Not mentioned is the noise floor of typical playback environments which are generally far poorer yet, and have a spectral shape that is more like that of recording studios and the like. How many complain about the noise floor of say Sansa Clips and Fuzes which are well known to be in the -85 to -95 dB range?
Measurements of generally well-regarded sources (http://nwavguy.blogspot.com/2011/02/rightmark-audio-analyzer-rmaa.html)
(http://2.bp.blogspot.com/_gnU30vMbtYg/TUrgUXmHaWI/AAAAAAAAABM/h7TFcuvPn0s/s400/rmaa-problems.jpg)
One of the greatest contributions from RMAA to consumer audio world is that manufacturers are forced to use excellent ADCs even for $100 soundcards.
I suspect that the chicken came before the egg. ;-)
My view is that DAC technology progressed to the point where it wasn't worth building a sound card audio chip without a halfways decent DAC in it.
It was competition among the vendors that made it happen.
Realtek's commanding market share didn't hurt.
RMAA allowed a large number of people to observe the process by which this happened.
In fact the popularity of USB DACs has seems to have led to a fairly massive disimprovement in computer audio interface performance. I've been testing a fair number of pro and consumer USB audio interfaces and many have relatively massive artifacts due to their USB interfaces. The 7 KHz spike that Archimago has made famous seems to be pretty popular.
On balance their performance is probably good enough for human ears, but the working devices often vastly underperform their DAC chips. USB DACs from a few years back such as the eMU 0404 don't seem to have a lot of modern competition.
I mean ADC and it is not a typo. People like to share their results on the internet therefore manufacturers need to use better ADCs on their products otherwise the loopback results will look ugly. I still remember tomshardware made a mistake in looping the Audigy in around 2000, which resulted in poor frequency response, then Creative uploaded a RMAA guide for users to test their cards. Since then Creative also have their RMAA guide included in later flagship soundcards and Asus also have their guide to test their flagship Xonar cards.
http://audio.rightmark.org/download.shtml (http://audio.rightmark.org/download.shtml)
My X-Fi scored 119dB in loopback tests.
http://www.hydrogenaud.io/forums/index.php?showtopic=100481 (http://www.hydrogenaud.io/forums/index.php?showtopic=100481)
But now manufacturers are not interested to make PCI soundcards anymore and there are many USB DACs without ADC function.
I mean ADC and it is not a typo.
Thanks for the correction.
Traditionally, audio interfaces have had symmetrical performance.
The asymmetrical products probably exist due to budgetary considerations.
I don't see the Rightmark program, as much as I appreciate it, as being a strong influence simply because almost every time I google for a Rightmark test for a product, there is none.
In fact the popularity of USB DACs has seems to have led to a fairly massive disimprovement in computer audio interface performance. I've been testing a fair number of pro and consumer USB audio interfaces and many have relatively massive artifacts due to their USB interfaces. The 7 KHz spike that Archimago has made famous seems to be pretty popular.
On balance their performance is probably good enough for human ears, but the working devices often vastly underperform their DAC chips. USB DACs from a few years back such as the eMU 0404 don't seem to have a lot of modern competition.
In reply to your comments on recent USB interfaces, I agree there are some regressions. The only USB RMAA result I can find which is better than my PCIe X-Fi is Lynx Hilo but it costs $2495 while my X-Fi is only $170 back in 2013. Benchmark DAC2 is another possible candidate but I can only see Audio Precision results in the manual, so the numbers may be incompatible with RMAA. I am highly interested to see John Siau post some results by using RMAA test signals to loop DAC2 and ADC1 as an article in Benchmark's site said their products already outperformed Audio Precision analyzers.
http://benchmarkmedia.com/blogs/news/40489...de-measurements (http://benchmarkmedia.com/blogs/news/40489089-benchmark-dac2-vs-dac1-side-by-side-measurements)
This is not even 16-bit performance, and the computer is practically idling:
https://onedrive.live.com/redir?resid=5B2A7...int=photo%2cPNG (https://onedrive.live.com/redir?resid=5B2A74A081A41676!107183&authkey=!ALcaS70VYIflf1o&v=3&ithint=photo%2cPNG)
I was more concerned about your claim of 80dB range or worse, but 85 dB isn't that bad, particularly if you did that as a loop back test. Take a look at this thread:
http://www.hydrogenaud.io/forums/index.php?showtopic=92637 (http://www.hydrogenaud.io/forums/index.php?showtopic=92637)
FWIW, the newer parts are a lot better:
http://www.anandtech.com/show/8797/asus-x9...rboard-review/5 (http://www.anandtech.com/show/8797/asus-x99-a-motherboard-review/5)
Although I don't think it really matters much in practice, unless maybe you're using a headphone amp.
In reply to your comments on recent USB interfaces, I agree there are some regressions. The only USB RMAA result I can find which is better than my PCIe X-Fi is Lynx Hilo but it costs $2495 while my X-Fi is only $170 back in 2013. Benchmark DAC2 is another possible candidate but I can only see Audio Precision results in the manual, so the numbers may be incompatible with RMAA. I am highly interested to see John Siau post some results by using RMAA test signals to loop DAC2 and ADC1 as an article in Benchmark's site said their products already outperformed Audio Precision analyzers.
http://benchmarkmedia.com/blogs/news/40489...de-measurements (http://benchmarkmedia.com/blogs/news/40489089-benchmark-dac2-vs-dac1-side-by-side-measurements)
I've seen a lot of RMAA results for the Hilo, but none seem to clarify that they were made using the USB interface. Both the Hilo and the DAC2 can be operated using other sources than USB-2 and the issues that I see in other products are USB-2 related.
This is not even 16-bit performance, and the computer is practically idling:
https://onedrive.live.com/redir?resid=5B2A7...int=photo%2cPNG (https://onedrive.live.com/redir?resid=5B2A74A081A41676!107183&authkey=!ALcaS70VYIflf1o&v=3&ithint=photo%2cPNG)
I was more concerned about your claim of 80dB range or worse, but 85 dB isn't that bad, particularly if you did that as a loop back test. Take a look at this thread:
http://www.hydrogenaud.io/forums/index.php?showtopic=92637 (http://www.hydrogenaud.io/forums/index.php?showtopic=92637)
FWIW, the newer parts are a lot better:
http://www.anandtech.com/show/8797/asus-x9...rboard-review/5 (http://www.anandtech.com/show/8797/asus-x99-a-motherboard-review/5)
Although I don't think it really matters much in practice, unless maybe you're using a headphone amp.
The -85dB number came from the Tascam. I had to use 18dB of gain because of the onboard audio's laughable output. -80dB might have been from a loop back, or just an exaggeration from memory.
Aren't those Tom's Hardware examples all $200+ enthusiast motherboards reviewed in enthusiast magazines, along with the motherboard used in the original ABX? Hardly a typical end-user system, and I doubt mine is the worst example...
Of course I'm using a headphone amp.
I've seen a lot of RMAA results for the Hilo, but none seem to clarify that they were made using the USB interface. Both the Hilo and the DAC2 can be operated using other sources than USB-2 and the issues that I see in other products are USB-2 related.
I don't like USB interfaces because they generally have higher latency and CPU usage than PCI/e ones, and they usually don't support multiclient ASIO except for some expensive models. I am a virtual instruments user so these are essential requirements.
I didn't notice USB interfaces' sound quality issue is caused by the type of connection until you mention it and I am pretty surprised. In another forum a member asked for a solution to hook up an Onkyo soundcard with only one stereo line out and a toslink output to powered speakers and headphones with an ability to switch between speakers and headphones without too much hassle, and he doesn't want to give up using the soundcard completely. I recommended a $60 SMSL SPDIF only DAC with headphones amp while another member (A) recommended a USB-only one. I said using USB is inconvenient because the OP need to switch between audio devices in Windows control panel and/or audio/video player device preferences and A said that it is a common sense to avoid toslink since it is jittery. SIGH.
Actually toslink measured better than other electrical interfaces at my home because it can effectively avoid ground loop.
The -85dB number came from the Tascam. I had to use 18dB of gain because of the onboard audio's laughable output. -80dB might have been from a loop back, or just an exaggeration from memory.
Aren't those Tom's Hardware examples all $200+ enthusiast motherboards reviewed in enthusiast magazines, along with the motherboard used in the original ABX? Hardly a typical end-user system, and I doubt mine is the worst example...
Of course I'm using a headphone amp.
I hope the Tascam's gain is analog otherwise 18dB is a big penalty to SNR. My motherboard is only an el cheapo ASRock H55DE3 with VT1718S codec but I only have 5dB level differences when recording using my X-Fi.
I didn't notice USB interfaces' sound quality issue is caused by the type of connection until you mention it and I am pretty surprised. In another forum a member asked for a solution to hook up an Onkyo soundcard with only one stereo line out and a toslink output to powered speakers and headphones with an ability to switch between speakers and headphones without too much hassle, and he doesn't want to give up using the soundcard completely. I recommended a $60 SMSL SPDIF only DAC with headphones amp while another member (A) recommended a USB-only one. I said using USB is inconvenient because the OP need to switch between audio devices in Windows control panel and/or audio/video player device preferences and A said that it is a common sense to avoid toslink since it is jittery. SIGH.
Actually toslink measured better than other electrical interfaces at my home because it can effectively avoid ground loop.
Toslink is very good for the reason you mention - its complete and total electrical isolation.
Ironically, USB 2.0, at least at the lower speeds used with stereo audio interfaces, can be totally electrically isolated because the signal wiring is transformer coupled.
The higher speed forms of USB 2.0 that are associated with products such as external hard drives appear to have lost the transformer coupling in the quest for speed.
The specific faults that I am seeing appear to be related to the packetizing of audio data.
This is further described here:
Apple TNL about USB 2 packet sizes and rep rates (https://developer.apple.com/library/mac/technotes/tn2274/_index.html)
with some user experiences here:
Archimago report of USB packet noises (http://archimago.blogspot.com/2015/05/measurements-usb-hubs-and-8khz-phy.html)
Thanks for the replies guys. However, I was hoping for something of a larger scale. For example, when we do drug trials or crime statistics, we look for a much larger sample size than 2 people. I understand that doing thousands upon thousands tests like this will be impractical but I was hoping for maybe a test of 10, 20, 30, 40, 50 people.
You can't extrapolate from bench measurements + known limits of human hearing?
Do your own experiments if that's insufficient. Because who, exactly, is going to perform (and pay for) the experiments you require? DAC makers? Why would they?
This isn't about my own ability to discern a difference, it's about human beings' abilities to discern a difference in general, and whether we can just say that Odac is transparent, full stop and anybody that disagrees is wrong.
You seem to have ignored my first (rhetorical) question.
But at least now we have a better idea of the axe you're intending to grind.
Bruh, you don't even know me.
I personally believe Odac is transparent. I hope it is possible to ask questions without people questioning each other's motivations.
I feel it would be a stronger case if there was some sort of study out there that pulled 50, 100 people and did a double blind study about transparency of say, the Odac. There are many ways to ignore the results, but I think it would convince some people. I only came up with this thread because somebody I knew felt this would be the nail in the coffin for him.
I personally believe Odac is transparent.
I feel it would be a stronger case if there was some sort of study out there that pulled 50, 100 people and did a double blind study about transparency of say, the Odac.
What are you waiting for bruh?
Let me guess, non-belivers to spend their time doing all the heavy lifting searching for yet another witch effect, so that believers can ignore the results.
I personally believe Odac is transparent.
I feel it would be a stronger case if there was some sort of study out there that pulled 50, 100 people and did a double blind study about transparency of say, the Odac.
What are you waiting for bruh?
Let me guess, non-belivers to spend their time doing all the heavy lifting searching for yet another witch effect, so that believers can ignore the results.
You seem a little pessimistic about the whole situation. It ain't all that bad.
Let me guess, non-belivers to spend their time doing all the heavy lifting searching for yet another witch effect, so that believers can ignore the results.
What are you saying exactly?
Sane people might not have time nor desire for a large scale double blind test, to see whether an ODAC et al, is "transparent".
cheers,
AJ
Sane people might not have time nor desire for a large scale double blind test, to see whether an ODAC et al, is "transparent".
Sane people might look at the ODAC's excellent measured performance and see no need for that large scale DBT.
Why shouldn't ODAC nay-sayers be obliged to follow the same stardards as ODAC proponents?
I feel it would be a stronger case if there was some sort of study out there that pulled 50, 100 people and did a double blind study about transparency of say, the Odac. There are many ways to ignore the results, but I think it would convince some people...
For the group of people who claim the piece of gear is
not transparent, all they have to do is find
one single person who can hear a difference, using scientific protocols to preclude bias such as level matching and DBTing, using whatever music they wish,
and they win the argument.
For the group of people who claim the piece of gear
is transparent, all they have to do is test
every single person on the planet, with
every single song ever recorded, through
every price no object audio system, otherwise when their 50, 100, or 100 million test subjects fail to hear the difference it will simply be dismissed by the Stereophools with the exact same three reasons they
always use, and which I listed earlier:
- you used the wrong people with inadequate hearing and/or training
- you used the wrong, non-revealing music
- you used inadequate playback gear which obscured the subtle differences
Which group of people has the easier task of providing the burden of proof that their rivals insist upon?
I feel it would be a stronger case if there was some sort of study out there that pulled 50, 100 people and did a double blind study about transparency of say, the Odac. There are many ways to ignore the results, but I think it would convince some people...
For the group of people who claim the piece of gear is not transparent, all they have to do is find one single person who can hear a difference, using scientific protocols to preclude bias such as level matching and DBTing, using whatever music they wish, and they win the argument.
Except if a single instance is 'not transparent' , that does not mean that a listener can be expected to be 'blown away' by the difference, 'even my wife could hear it', 'veils were lifted', etc. And THAT is the rhetorical norm in audio difference reporting.
Simply passing the 'not transparent' threshold doesn't cut it. Let's not let audiophiles get away with such bluster (e.g., wild extrapolations from the Meridian report on digital filter difference).
I respectfully disagree. If a person can show with strong statistical significance that they can reliably hear a difference using normal music, not special test tones or signals that don't represent real world use, then it is their call, not mine, as to whether this is important to them or not.
"Night and day diffrerence" has no exact definition, whereas "audible vs inaudible on music" does.
I'd rather focus on exposing the possible errors* of their test, and how these errors were used as tells, rather than endlessly arguing if "a little bit different" is, or isn't, of great importance.
Speaking of Stuart et al, he played the card "you used inadequate playback gear which obscured the subtle differences" preemptively when he wrote at the end of his paper's summary:
"an audio chain used for such experiments must be capable of high-fidelity reproduction."
Now if anyone attempts to replicate his study using less than the DSP7200SE speakers that were used, with a response to over 32kHz and a price tag of *gulp* $46,000, all he has to do is say "See, I told ya. Your system was inadequate".
Hmm, I wonder how many other researchers have access to $46K speakers?
*- Dither? The wrong kind was used with a lame explanation as to why.
- Filter slopes used? Unusual and not "typical" at all, according to Arny.
- Level matching to 0.1dB or less? No discussion in the paper, everyone but me just "assumes" he did it, and since he foolishly might think response over 20k has meaning he also might have used weighting which included content above 20k [ITU does this I believe] to determine the level matching which is dead wrong and will skew things in the truly audible range.
- Time alignment and latency after processing the signal causing audible tells, like I demonstrated in the AVS AIX test comparison both through my ABX scores and Audacity analysis [I learned just for the occasion, BTW]? None mentioned.
Sigh.
Would you mind reiterating what the success rate was? Now tell us how this doesn't say something about the extent of the difference that was audible.
*- Dither? The wrong kind was used with a lame explanation as to why.
The results showed this to be irrelevant.
Filter slopes used? Unusual and not "typical" at all, according to Arny.
According to Arny? He hasn't exactly demonstrated mastery over digital filters. I'm afraid you'll have to do better.
Time alignment and latency after processing the signal causing audible tells, like I demonstrated in the AVS AIX test comparison both through my ABX scores and Audacity analysis [I learned just for the occasion, BTW]?
Again, I refer you to the success rate of the test.
Inexact level matching could have made the difference, however I think it's probably safe to assume this wasn't an issue. It wasn't like they were comparing different hardware.
New post instead of editing my previous (apologies in advance if I decide to merge them later).
Intermodulation distortion was not ruled out as a cause for differences heard.
Sigh.
Would you mind reiterating what the success rate was?
56% in aggregate form over many trials, if I understand correctly. I mocked how unimportant this would be (from
my perspective at least) here (http://www.avsforum.com/forum/91-audio-theory-setup-chat/1598417-avs-aix-high-resolution-audio-test-take-2-a-32.html#post30863730):
"Imagine the sales pitch: "Ladies and Gentlemen, come one, come all, wait till you hear our incredible new Hi-Re$ sound system that blows CD away! True, you may not be able to hear the difference on your own, as an individual, but merely invite seven of your closest friends over, listen through my necessary $46,000 speakers*, use my specially prepared samples only, cast your votes over several listening trials, sum your totals, and then finally examine the results in aggregate form, AND BINGO! 56% correct responses don't lie (instead of a random coin flip's 50% results) and it conclusively shows, with statistical significance, that yes, you made the right decision to only buy THE BEST!" - not a real quote
*- "audio chain used for such experiments must be capable of high-fidelity reproduction" [This is a real quote. It's the last line of the paper's abstract, protecting him from any subsequent failed attempts to replicate his findings, by others who may discredit his paper: https://secure.aes.org/forum/pubs/conventions/?ID=416 (https://secure.aes.org/forum/pubs/conventions/?ID=416) ] "But your test setup didn't use $46K speakers, now did it?!" He'll protest.
- "high fidelity" defined by me, or authorized agents of Meridian Audio, details not specified nor provided upon request
- offer not valid under test supervision by a disinterested third party
- must use exact, unpublished, unreleased down converted samples held in my possession
- alternate forms of conversion, music, or the use of superior dither disallowed
- any attempt to measure the down converted sample's level match to the original, possibly showing a minor mismatch, as was found in the initial AIX records' down conversion samples for the AVSforum tests, for example, is disallowed. "
Now tell us how this doesn't say something about the extent of the difference that was audible.
I never said the difference was strong, in fact I pointed out how trivial it was in my mockery of the 56% figure, however it does technically exist (assuming his test was fair, which I'm not thoroughly convinced of) and shows statistical significance based on the number of trials. [Although, as I understand it, not a single person in the test showed an ability on their own to hear a significant difference, it was only when all the results were pooled together, and that's what I was making fun of in the above quote. Would an audiophile (with such Hi-res gear) really brag to their friends about
that?]
My point is arguing over what is and what isn't "important" is a judgement call and will have no conclusion. Arguing over "is or isn't audible on music" is however more of an exact thing, hence of more interest to me personally. YMMV.
Inexact level matching could have made the difference, however I think it's probably safe to assume this wasn't an issue. It wasn't like they were comparing different hardware.
Software filters, not just hardware filters, cause level changes too, when the level matching procedure uses an inappropriate form of frequency band weighting.
Speaking of Stuart et al, he played the card "you used inadequate playback gear which obscured the subtle differences" preemptively when he wrote at the end of his paper's summary:
"an audio chain used for such experiments must be capable of high-fidelity reproduction."
Now if anyone attempts to replicate his study using less than the DSP7200SE speakers that were used, with a response to over 32kHz and a price tag of *gulp* $46,000, all he has to do is say "See, I told ya. Your system was inadequate".
A speaker does not have to be outrageously expensive to have reasonably flat super-high frequency response.
All of Adam Audio's studio monitors with their folded ribbon tweeter have treble response to ~50kHz at -3dB, and there are plenty of other speakers available with similar treble extension at similarly non-crazy prices. The practical application of this is debatable, of course, but you don't have to spend $46K to get that kind of frequency range.
And considering those are some of the most highly-rated studio monitors out there, anyone claiming that they are incapable of "high-fidelity playback" must be out of their mind.
Software filters, not just hardware filters, cause level changes too, when the level matching procedure uses an inappropriate form of frequency band weighting.
With anti-aliasing/imaging filters this is a bit of a stretch.
KozmoNaut, I was merely mentioning one specific aspect of his $46k speakers that were used. I didn't mean to imply ultra high frequency response is all that matters but as soon as anyone attempts to replicate his study with speakers that don't go up to 32kHz, or beyond , I'll bet Stuart will be quick to point it out.
Software filters, not just hardware filters, cause level changes too, when the level matching procedure uses an inappropriate form of frequency band weighting.
IIRC, forum member David (?) mentioned that the current incarnation of ReplayGain used in Foobar2K ABX, [which I don't follow closely so perhaps things have changed] used weighted filtering that
takes ultrasonics into consideration in its estimation of level. So for instance, in comparing song 'A' with ultrasonic content to the same song 'B' with everything above, say, 20kHz stripped away, it inappropriately lowers the overall level of 'A' because it weighs those ultrasonics as being part of overall power level of the music.
[I can't remember what thread this discussion took place in, unfortunately.] The end result is the "level matched" audible level of 'A' and 'B' will be off, over the audible <20kHz range. Arny's "keys jangling" files, as I recall it, might be an example of where this problem would show up, perhaps, I'm not sure, and it wouldn't surprise me if Meridian's files would suffer from the same issue, however to the best of my knowledge Meridian has never made available the actual processed and unprocessed files, nor spoken a single word about how, and to what level of accuracy, the files were level matched.
KozmoNaut, I was merely mentioning one specific aspect of his $46k speakers that were used. I didn't mean to imply ultra high frequency response is all that matters but as soon as anyone attempts to replicate his study with speakers that don't go up to 32kHz, or beyond , I'll bet Stuart will be quick to point it out.
Yes, but as KozmoNaut points out, your price inclusion is a red herring. It wouldn't be hard to find a far less expensive speaker with that high extension. Heck, there are $40 planars that extend to 40k with less drama than that dome.
The problem with any repeatability test is the lack of system details regarding the whole mess. But if >30k response is required for the "benefits" of MQA, it might be DOA, as very few speakers on the market, even the "audiophile" one, would qualify.
If you read the comments on the paper AES site, there has been some backpedalling that would make Deon Sanders proud. Including an admission that the whole "cognitive load" aspect might have been a load of BS:
However, we accept that the use of the term “cognitive load” was perhaps over-reaching as we used it.
I guess the "smearing" aspect remains a "hypothesis":
Point 3 is perhaps worded unhelpfully generally, but it is not untrue that our results are consistent with such a temporal smearing hypothesis; we do not claim that our results support this hypothesis.
No mention of whether the claim in their own manual about TPDF being transparent will be, ummm, corrected to:
Turning to the comments on dither: we know that in order to approach transparency TPDF is the minimum that should be accepted.
"Approach transparency".
cheers,
AJ
Maybe this post, mzil? https://www.hydrogenaud.io/forums/index.php...st&p=895311 (https://www.hydrogenaud.io/forums/index.php?s=&showtopic=107570&view=findpost&p=895311)
Yes eric.w, good find. David's response below it, and your testing, confirms what I warned of.
[Yes, but as KozmoNaut points out, your price inclusion is a red herring.
If I perhaps gave you or anyone else the impression I respect Stuart or his grossly overpriced speakers, you are mistaken.
What we do know is he preemptively used the "your gear is inadequate" card, right
in the abstract itself. As to what makes his gear "hi-fi" enough, none of us really know. He can conveiniently manufacture whatever it needs to be at the time when bad mouthing any subsequent studies by others, should he need to. No reason for him to show his cards prematurely before the showdown when he doesn't need to.
From the paper by Stuart et al (http://www.aes.org/e-lib/browse.cfm?elib=17497) opening abstract:
"Two main conclusions are offered: first, there exist audible signals that cannot be encoded transparently by a standard CD; and second,
an audio chain used for such experiments must be capable of high-fidelity reproduction. " [bold text emphasis mine]
"Must be"? Funny how that "lesser, not as high-fi audio chain", which didn't cut it and failed to show any differences, I guess, never eneded up being discussed in his paper.
But he's not really saying that you must have expensive audiophile-approved speakers. I read it as a him making a point that unless your entire signal chain is actually capable of super high-frequency signal reproduction, there is absolutely no chance you will hear a difference, no matter if it's technically audible or not.
A lot of gear will impose an upper limit on frequency response, maybe because response above 20kHz is simply not specified and the manufacturer only cared about 20Hz-20kHz, maybe they even put a lowpass filter in there to avoid ultrasonic harmonic interference in the audible range.
Or if there's a DSP in there, the frequency range is limited by sampling rate. For instance, even though my speakers technically go to 50kHz, they will never ever get an input above 24kHz, because my DSP crossover uses 48kHz sampling rate ADCs/DACs.
I feel it would be a stronger case if there was some sort of study out there that pulled 50, 100 people and did a double blind study about transparency of say, the Odac.
Back in the 1970s and 1980s when we invented ABX, we did DBT power amp comparisons involving about 25 different people and found our classic "no differences" results. The work was repeated with a similar size group of people in the 1990s with similar results.
The ODAC is a far cleaner piece of gear than most of the gear we tested then.
There are many ways to ignore the results, but I think it would convince some people. I only came up with this thread because somebody I knew felt this would be the nail in the coffin for him.
Don't underestimate the power of greed and denial.
I respectfully disagree. If a person can show with strong statistical significance that they can reliably hear a difference using normal music, not special test tones or signals that don't represent real world use, then it is their call, not mine, as to whether this is important to them or not.
"Night and day diffrerence" has no exact definition, whereas "audible vs inaudible on music" does.
But in the real world, real audiophiles make real claims like 'night and day'. All the time.
'Audible' doesn't matter so much as 'HOW audible'
Btw what's the exact definition of 'strong statistical significance' and 'reliably'? And 'normal music'?
I'd rather focus on exposing the possible errors* of their test, and how these errors were used as tells, rather than endlessly arguing if "a little bit different" is, or isn't, of great importance.
I'd rather focus on what claims are being promulgated in the real world to consumers. In that regard I don't much care if a trained listener in a lab using the most sensitive conditions was able to detect a difference with pvalue just a bit less than 0.05. That's academically and scientifically interesting, but I want to know if the grand claims promoted every month since the 1970s by, say, the Michael Fremers and John Atkinsonses of the world, are likely to be true.
So, if an audiophile blowhard says, 'I auditioned Cable A and Cable B and wowie zowie, Cable B was clearly better sounding', I want to see
them replicate
that result, with everything the same
except 1) blind 2) level matched 3) random order 4) proctored.* Not some random and trained subject in a lab setting with gear and materials they haven't heard before. And not some Internet cowboy reporting unproctored results.
Audiophile blowhards should be able to
ace such a test. Their gear, their materials,
their claim. The results shouldn't be borderline.
Hmm, why don't we see more of such tests?
*if this sounds familiar, I'm thinking of the Mike Levigne cable tests on AVSF, one of the few instances where my wish was granted. The Zipser trials of amps is another.
Hmm, why don't we see more of such tests?
Because it takes months of listening to create solid day/night differences in your head.
Isn't it usually going to be the new thing you haven't yet bought that's going to make an improvement over something you already have? And if you already have the latest and greatest, you can always tape another bag of pebbles to something.
'Audible' doesn't matter so much as 'HOW audible'
What "levels of audibility" scale do you personally like best? What test instrument do you use to measure it and how do you calibrate it? Or do you simply take people's word for it on an arbitrary scale you've concocted like Olive does?
If a person says a volume difference of .5 dB is "night and day", how can you prove they are lying? You can't. If they can prove they can hear it, which they probably can under the right conditions, then you are stuck. It is a pointless path to follow that get's you nowhere.
"Night and day" has no measurable defininition. "Audible" and "inaudible" do.
I'm with jj: preference in inviolate, and arguing that everyone fits into the same "annoying to pleasurable" scale is absurd, in
my view [I'm not sure how jj feels on that part]. As an analogy, some people are easily bothered when the room temperature is just a couple of degrees above 72 degrees F whereas other people don't care at all if it is 10 degrees hotter. Neither group is "wrong" , they are just different, and I don't care if polls of 100 million other people say on average a difference of 2 degrees should be deemed " hardly annoying at all" whereas 10 degrees is "night and day". All I care about is under scientifically controlled conditions can that two degree guy show an ability to feel a difference, yes or no? How much does it annoy him? I don't care. It's his business.
Btw what's the exact definition of 'strong statistical significance' and 'reliably'? And 'normal music'?
Are you asking what I
personally use when I'm taking money from audiophiles when betting them that their claims are bogus?
'Audible' doesn't matter so much as 'HOW audible'
What "levels of audibility" scale do you personally like best? What test instrument do you use to measure it and how do you calibrate it? Or do you simply take people's word for it on an arbitrary scale you've concocted like Olive does?
If a person says a volume difference of .5 dB is "night and day", how can you prove they are lying?
You can never prove that a person is intentionally presenting false claims as being true (i.e., meeting the actual formal definition of lying) without some usually hard-to-obtain evidence about what they know and mean.
You can't.
It is like any other negative hypothesis - difficult or impossible to prove.
If they can prove they can hear it, which they probably can under the right conditions, then you are stuck. It is a pointless path to follow that get's you nowhere.
It may be ironic that everybody I know who has provided reliable evidence that they can hear a 0.5 dB difference with music will generally stop well short of calling it "Night and Day".
"Night and day" has no measurable definition.
Agreed. Typically, its hyperbole.
"Audible" and "inaudible" do.
But they vary with the circumstance.
I'm with jj: preference in inviolate, and arguing that everyone fits into the same "annoying to pleasurable" scale is absurd, in my view [I'm not sure how jj feels on that part]. As an analogy, some people are easily bothered when the room temperature is just a couple of degrees above 72 degrees F whereas other people don't care at all if it is 10 degrees hotter. Neither group is "wrong" , they are just different, and I don't care if polls of 100 million other people say on average a difference of 2 degrees should be deemed " hardly annoying at all" whereas 10 degrees is "night and day". All I care about is under scientifically controlled conditions can that two degree guy show an ability to feel a difference, yes or no? How much does it annoy him? I don't care. It's his business.
There may be a rational and relevant scale for evaluating preferences - preferences that are based on reliable perceptions, and those that are not.
Said briefly, "If there is no reliable audible difference, then there can be no rational preference".
Btw what's the exact definition of 'strong statistical significance' and 'reliably'? And 'normal music'?
Are you asking what I personally use when I'm taking money from audiophiles when betting them that their claims are bogus?
This could be begging the question. What is "an exact definition"? Got an exact definition for that? ;-)
Seriously, as humans we constantly work in a universe of inexactitude, yet we often operate reliably and rationally in it.
My definition of "normal music" depends on the circumstance, but I vacillate between something that comes from a commercial recording, to something that is not pathological.