Digital Audio Explained (from an engineer's standpoint)

[shelly_d]

It was pretty crappy, wasn't it? Do you use a $300 player?

I really don't see why you are fixed on the cost of the equipment.

Apparently, their panel could not hear what the Ayre engineers could in developing the alternative filter position. Ok.

Or they were looking for a technical change to give their markeing a boost or they buy into the same "brickwall" theory that you do. Lots of companies develop and market devices that solve problems that really don't need solving in the grand scheme of things.

5. Running arbitrary SACD content through mediocre gear using ABX boxes renders the test an absolute joke.

Believe that if you wish. I think it says a lot about your belief structure.

Did that BAS test have any effect on the industry recording process or production of any audio equipment? Just lots of smiles.

With a great deal of business already invested in product and people out there ready to dismiss any double blind testing no matter the results, I wouldn't give up a product line either.

Shelly_D

 

[nailer]

The vast majority of CDPs exhibit multiple cycles of pre-ringing when attempting to run flat to 20 khz.

(bold added)

Please provide documentation to support this claim.

 

[JP]

Just use 10 second samples if you want to post a test - you'd have to be crazy to claim that's not fair use when there's a specific purpose for it. I'm not really interested; I've already failed that test, as well as MP3s 256kbps and up, once I started trying actual ABX for such things, and I ain't ashamed to say so. If I need an ego boost, I'll just think about how I can perform far above average on pitch perception and distortion hearing tests . It was kind of thrilling, in a way, having my certainty about hearing differences evaporate in a matter of seconds. No amount of non-blind A/B gets you that feeling.

If you do post a test and a bunch of people say they passed it, I'll perk up, and give it go too. After seeing many, many proposals for such tests and even starting a couple of threads proposing them with instructions, I would say don't get your hopes up.

There's also the issue of getting it done. With a studio setup and pro audio software, it's a piece of cake: if you don't already have an automated plugin, there's a still going to be a simple enough way to use A/B functions for ABX. Otherwise, it's a bit of a pain and has very setup-specific concerns. Redbook vs lower is a little easier, since you can pretty much use the foobar ABX for anyone with a computer source (still potentially useable for higher quality, but OS/driver issues come into play). Whatever you do, don't forget statistics. 8/10 correct doesn't mean anything, unless you get it over and over, but then it's not /10 anymore.

Here's a related rather hopeless thread I made recently (new year's eve afternoon, apparently) http://audiokarma.org/forums/showthread.php?t=565342

Thanks! My hopes aren't up, and truth be told for selfish reasons of time I hope there's little demand.

I thought about 10s and calling it fair use (I've no problem doing that) but I don't know if that's a long enough sample? Last thing I want to do is go through this and then have people say "well, we only had ten seconds of content"... amongst the things that'll be said anyway.

It's been a decade or so since I've done anything like this, and I had access to studio gear back then. I wasn't aware the foobar ABX plugin had an issue? Any recommendations for PC based free software?

The issue has always been about CD copies. I used EAC and Roxio. Now use dbPoweramp for ripping.

Were your copies actual copies or rips that you then made a CDA out of? Any bit level analysis if they were actual copies?

 

[E-Stat]

I really don't see why you are fixed on the cost of the equipment.

So what $300 player do you find matches the performance of say an EMM Labs player? I'm sure everyone would be truly interested in such a scoop. Did you see the system in the picture I posted? Do you really think that is representative of a high performance audio system?

Or they were looking for a technical change to give their markeing a boost or they buy into the same "brickwall" theory that you do. Lots of companies develop and market devices that solve problems that really don't need solving in the grand scheme of things.

Speculate on...

Believe that if you wish. I think it says a lot about your belief structure.

Real scientific test document the methodolgy and content so that others may replicate their results for verification. This *test* scientific? No danger there.

With a great deal of business already invested in product and people out there ready to dismiss any double blind testing no matter the results, I wouldn't give up a product line either.

Yeah, it's all the bad guys in the industry trying to prop up their marketing creation, right? I see you're into conspiracy theories.

So who killed Kennedy?

 

[E-Stat]

I thought about 10s and calling it fair use (I've no problem doing that) but I don't know if that's a long enough sample?

A ten second sample? Most certainly not. Who on earth would consider that to be of any value?

I'll be happy to compare tracks using my Squeezebox Touch players located far from the server. I use Foobar for running the in house system, but that is strictly car stereo fidelity using in-ceiling speakers.

 

[E-Stat]

Please provide documentation to support this claim.

Simply observe the measured FR response on Stereophile. Home Theatre, Audioholics, etc.

Show me others that have noticeable roll off at the top octave since that is required.

 

[JP]

I'll be happy to compare tracks using my Squeezebox Touch players located far from the server.

I don't understand how a valid ABX can be done that way. Can you elaborate?

 

[nailer]

Simply observe the measured FR response on Stereophile. Home Theatre, Audioholics, etc.

Show me others that have noticeable roll off at the top octave since that is required.

In other words, you can't support your statement.

 

[dumptruck]

Believe that if you wish. I think it says a lot about your belief structure.

Unlike a lot of other things said here, dismissing the equipment used is a relatively reasonable criticism/hypothesis when it comes to audibility of a pretty tiny difference. If one thinks the reproduction equipment wasn't up to the test, they can go do a better one. Heck, try to set it up for a positive result: crank up the HF response, use a recording with lots of HF content and very little reverb, put the tweeters 2" from your ears. Try to establish a baseline where a difference is audible that others can duplicate. It might very well be possible, but you'd probably be the first.

A ten second sample? Most certainly not. Who on earth would consider that to be of any value?

I'll be happy to compare tracks using my Squeezebox Touch players located far from the server. I use Foobar for running the in house system, but that is strictly car stereo fidelity using in-ceiling speakers.

If you don't think a selected 10 seconds is enough, that's your call. Do you know what ABX is? You have to listen to two tracks, and then a third that is one or the other, and pick which one of the first two is the same as the third. Then you need to do that at least 9 more times (the more you do, the greater your chances for a positive result, until fatigue sets in).

With a squeezebox, I suppose you could do it, but it would be much more difficult than with ABX or even A/B software because you couldn't switch back and forth as it plays.. hmm..

edit: I think you'd need a helper in control of the server and a coin. Helper puts both tracks on a playlist, flips a coin for which goes first, flips a coin again for which track is added again as third, you listen to all three tracks however you want as much as you want, make the call, and repeat from the start with new coin flips. That's the easiest I can think of for a squeezebox. Not being able to switch from A to B while continuously playing makes it MUCH harder, though.

 

[shelly_d]

Or they were looking for a technical change to give their markeing a boost or they buy into the same "brickwall" theory that you do. Lots of companies develop and market devices that solve problems that really don't need solving in the grand scheme of things.

Speculate on...

Perhaps 5 or 10 minutes watching late night infomercials will convince you.

With a great deal of business already invested in product and people out there ready to dismiss any double blind testing no matter the results, I wouldn't give up a product line either.

Shelly_D

Yeah, it's all the bad guys in the industry trying to prop up their marketing creation, right? I see you're into conspiracy theories.

So who killed Kennedy?

Would you end a profitable business line of equipment based upon one study if it still was profitable? I think not. And it was Lee Harvey Oswald.

Real scientific test document the methodolgy and content so that others may replicate their results for verification. This *test* scientific? No danger there.

There was more then enough scientific detail in that report to replicate the experiment. They documented the methodolgy quite well, dispite what you may think.

Shelly_D

 

[E-Stat]

Heck, try to set it up for a positive result: crank up the HF response, use a recording with lots of HF content and very little reverb, put the tweeters 2" from your ears.

I have no way of "cranking the HF response" (why would anyone want to do that? ) and there are no tweeters in my system.

If you don't think a selected 10 seconds is enough, that's your call.

Is your evaluation process that shallow?

Do you know what ABX is? You have to listen to two tracks, and then a third that is one or the other, and pick which one of the first two is the same as the third.

Sure. Just don't insert bogus boxes in the mix or change the way I normally play content.

Not being able to switch from A to B while continuously playing makes it MUCH harder, though.

Sorry, I don't find value with instant Cowboy audio comparisons. I find that long term listening is the only way to fully ascertain the capabilities of a component.

 

[E-Stat]

There was more then enough scientific detail in that report to replicate the experiment. They documented the methodolgy quite well, dispite what you may think.

So, which recordings were used? Kindly show documentation.

Isn't that a pretty important part of the test?

 

[dumptruck]

I have no way of "cranking the HF response" (why would anyone want to do that? ) and there are no tweeters in my system.

I said why in what you quoted.

Is your evaluation process that shallow?

Not necessarily, I wasn't being sarcastic when I said the length of the track is your call.

Sorry, I don't find value with instant Cowboy audio comparisons. I find that long term listening is the only way to fully ascertain the capabilities of a component.

Fair enough, and in that case, the squeezebox method I described in my post edit above would not be much of a hinderance at all, although I'm little confused about why a $300 CD player is laughable, but a $300 digital player with wifi and a touch screen is fine? I mean, don't get me wrong, I think it's fine.

 

[dumptruck]

So, which recordings were used? Kindly show documentation. Isn't that a pretty important part of the test?

Yes, I'll back you up on THAT one.

 

[E-Stat]

I don't understand how a valid ABX can be done that way. Can you elaborate?

Perhaps not. That's how I listen to digital content. I can compare two tracks.

 

[JP]

If you can't do it double blind, there's little point.

 

[shelly_d]

So, which recordings were used? Kindly show documentation.

Isn't that a pretty important part of the test?

Yes, I'll back you up on THAT one.

To repeat the test, the testers would be choosing their own music and set of equipment. The methods used and the listening levels and ambient noise levels would also be different. The important part of the test is the vary careful level adjusting, the very careful adherence to the Redbook standard for A/D D/A, consistency of phase inversion, not inversion, selection of test subjects and enough of a sample to be statistically valid. If the selections in this test were of such an origin that they were originally had the ringing that E-Stat speaks to, re running the same test with the same music would not prove anything. It is the very act of choosing different music with a different source and getting the same or different results that will either validate or repudiate this test.

Shelly_D

 

[E-Stat]

although I'm little confused about why a $300 CD player is laughable, but a $300 digital player with wifi and a touch screen is fine? I mean, don't get me wrong, I think it's fine.

Perhaps you might want to review how I actually use the Touch player instead of using erroneous speculations.

E-Stat's systems

 

[E-Stat]

To repeat the test, the testers would be choosing their own music and set of equipment.

That wouldn't replicate their test bed and most likely provide very different results.

Again, the scientific method is about duplicating a given set of test conditions to verify the same results.

 

[E-Stat]

If you can't do it double blind, there's little point.

No problemo. I already know the differences I hear between the different media.