Blue or red pill?

[pkane2001]

1 hour ago, beerandmusic said:

1. Use DSD256 file for comparison testing as it is the most demanding and provides the most detail..

19 minutes ago, beerandmusic said:

^^^ one thing about ethernet is that for any test, it should be on it's own segment...timing is critical...and any bandwidth use on same segment will interfere with results.

 

 

That's why high frequency DSD playback is not a good test  over a network compared to a file from local disk: there's a significant bandwidth requirement with demands on latency that could cause audible trouble if packets are lost or retried frequently. Obviously, serious errors and significant delays on the way to the DAC will account for differences in sound.

 

I have no problems playing PCM at 24/192KHz over my Wi-Fi, but there are obvious errors playing DSD256 and more so, DSD512. Wi-Fi has over 180Mb/s sustained, with low latency and no reported errors, and I'm using a repeater bridge next to the audio PC.

 

[pkane2001]

2 hours ago, manisandher said:

 

That was the original spirit of the invitation, and I hope it's still the case.

 

 

If this is to aid in "how to really test this", then I'm all for it.

 

Edit: If we stick to just files from the NAS vs. audio PC, then there really shouldn't be any need to verify they're the same - Mans can do the copying the files himself to make sure there's nothing underhand going on. However, streaming might also be of interest.

 

When I stream a file from Tidal and then listen to the exact same file on my NAS, they sound different to me. I'd like to demonstrate this to Mans. Let's say Mans agrees that they do indeed sound different. The obvious question then is: how do we know they're exactly identical? I can say, "because I say so", but that's not very convincing. I'd be quite happy to play the files back and capture the digital output of the audio PC and the analogue output of the DAC with the recorder.

 

Once Mans has verified that the two digital captures are identical (which they will be - I've done it many times already) and that the two analogue captures are virtually identical, within a small error (slightly drifting ADC clock, etc.), then Mans should be satisfied that the two files were indeed identical.

 

The thinking can then begin...

 

But if an A/B/X (the procedure for which I now understand) would be helpful, I'm happy to oblige. I could pick a few tracks that I think I'd be able to identify and we could see how I do. But I'd really, really prefer for this not to become to main focus of Mans' visit.

 

Mani.

Mani,

 

You are a good man to offer this invitation to Mansr! I am very interested in the outcome and the testing process.

 

I am curious as to how you’ll determine that the audio PC and the NAS source do not do something different to the data before it reaches the DAC? I would assume you’d use the same player software with the same settings in both cases?

 

Otherwise, what’s the guarantee that different filters, different up sampling methods or rates, or even different DSP settings will not be applied? (Apologies if this has already been discussed.)

[pkane2001]

21 hours ago, manisandher said:

 

For sure. My feeling is to use XXHighEnd for the most part (there's so much you can play around with), and HQPlayer for any streaming vs. local file comparison we might make. In all comparisons, the compared files will be bit-for-bit identical. I've discussed how we would verify that this is the case.

 

Mani.

 

Ok, just want to make sure that the same player software is used, with the same settings, when doing A/B comparisons -- there's a lot a player can do to the bits before these are sent out to the DAC, even if the source files are exactly the same.

 

[pkane2001]

3 minutes ago, sandyk said:

Not if both comparison files are saved to, AND played back from the same storage device, whether HDD,SSD,USB memory  OR even as adjoining tracks on a CD-R.

Mansr will find no differerences looking at DIGITAL files with identical checksums even if hears differences himself !!!

 

You’re missing my point.. Playing the same exact file using two different players or the same player with different settings can easily invalidate the test. You’re then comparing two players and their internal processing and not two storage devices. 

 

That’s why capturing the digital output to the DAC is critical to ensure that the same digital samples are being sent to it in both cases, as Mansr already said he’ll do.

[pkane2001]

2 minutes ago, sandyk said:

Mansr will NOT find any differences between DIGITAL files with identical checksums even if he reports hearing differences under correctly performed DBT conditions !

 

Anyone taking bets?

 

[pkane2001]

10 minutes ago, sandyk said:

A high Expectation  that you will hear differences, does not mean that you will hear verifiable differences under non sighted conditions. One reason could be that you aren't relaxed enough (stress) , and the other reason that there are none to hear !

 

What’s to stress about if you’re 100% certain you can hear the differences, you are listening in your own home, listening to your own system and music of your choosing? This is the case in this test, is it not?

[pkane2001]

12 minutes ago, beerandmusic said:

^^^ Does anyone NOT agree that if there are audible differences that the recording will show differences?

and wouldn't you be able to see the differences on an oscilloscope on the input to the D->A circuitry?

 

Do you need to ask? Pretty much all subjectivist audiophiles will disagree with this.

[pkane2001]

11 minutes ago, manisandher said:

 

Suggesting the possibility that I might not actually be hearing any real differences is something that I accept as healthy skepticism. Suggesting that I might go to the lengths of manipulating files isn't.

 

I agree. Regardless, Mans said he'll record the digital output to the DAC, so the bits can be compared. Any bits manipulation (intentional or unintentional) will be easy to discover.

 

[pkane2001]

7 minutes ago, PeterSt said:

 

Are you among those who think that copying a file will change the bits ?

haha

 

- File is on NAS - Play.

- Copy same File from NAS to local - Play.

 

When I once suggested to Barry Diament that checking for such a thing would be the utmost waste of time, he got angry with me.

But I guess such a thing happens when one really doesn't know digital.

 

When doing objective testing it's important to eliminate all sources of error or bias. So yes, bits should be compared, but not at the file level, but before they enter the DAC. 

[pkane2001]

2 minutes ago, Spacehound said:

If there's  any difference something's broken. 

And you would either hear  it very clearly as clicks and pops or similar  or there wouldn't be any sound at all. 

 

Not necessarily. For example, if the player software is using different filters, applying different SRC, applying volume compensation, etc., etc. depending on the source/path of the file. 

 

[pkane2001]

6 minutes ago, PeterSt said:

I like to bet you a 1000 euros that all arrives the same but the sound is different.

 

That is the subject of this test, if I understand it correctly. Mani agrees with you, Mans does not. And you'll pay 1000 euros to everyone on this thread who disagrees with Mani, should Mani fail the blind test, did I get that right?

 

 

[pkane2001]

1 minute ago, Spacehound said:

That's you telling the player to alter something. It won't alter it by itself. And the source doesn't matter - there is no 'history'. Noise is not transmitted from one section to the next either, unlike 'analog'. And it doesn't matter if the top of the bits look 'furry', or rounded off,  they are not detected at the top.

 

Nor do the paths , it's not like 'analog' where every 'process' degrades it by altering it slightly  or adding noise. That doesn't happen with 'digital'.

 

You have a limited imagination about what players can and cannot do. A player I'm using, for example, remembers the volume setting based on where the file was played from last time. This can easily produce a different output if I move the file to a different path.

 

[pkane2001]

13 minutes ago, Spacehound said:

If they've changed on route it will sound different. If they haven't it wont.  That's it. 

 

That's exactly the claim that is being tested. Unfortunately, you declaring that "That's it" will not prove anything to those who disagree with you. And there are a few here that do

 

 

[pkane2001]

2 minutes ago, manisandher said:

 

I did a quick SFS=20 vs. SFS=1 comparison for myself the other day, just to gauge how comfortable I'd be doing an A/B/X with it, and decided that I would be.

 

Is SFS=1 below the threshold of bits getting changed?

 

Mani.

 

What is SFS?

[pkane2001]

19 minutes ago, PeterSt said:

 

Mani, by far not. That would be in the 0.08 areas.

Btw, not (bits) changed, but samples skipped would be the correct term.

 

Wait... samples skipped? Why and when would you skip samples?

 

[pkane2001]

6 minutes ago, sandyk said:

Performing on command like a trained seal is very different to relaxed listening. Lengthy sessions demanded as proof , in my case raise my BP which degrades my hearing due mainly to an Acoustic Neuroma pressing on my right ear canal.
 After a large number of repeats, everything may start to sound the same, despite there being actual differences.
 As others have also reported , they may even cause a splitting headache.
 M.C. also made a remark about the stress factor .
 "A very experienced and fearless pair of ears who can be subjected to such tests and not worry in the slightest." 

 

Nobody is pressuring Mani. He chose the format, he chose the venue and he chose the music. He can do whatever listening evaluations he wants, as long as he can't tell which source is playing.  I've done tests like that many times and found it no more stressful than doing them sighted.

 

If not knowing which component is playing induces so much stress that the 'not subtle' differences become too subtle to distinguish, then perhaps one should pick another hobby.

[pkane2001]

3 minutes ago, PeterSt said:

 

Actually easy enough : when you can interrogate in sufficient detail what the whole (driver and processor) system does, you are capable of skipping at the sample level (normal timer resolution in Windows is 10ms minimum, but in XXHighEnd it is sub-sample (which is 1/705600 sec at least)). This is very creepy because at first not detectable and usually we only can imply stutter (like 1/10ths of seconds long stalls of samples not going through, that even influencing the frequency).

 

Of course this is not what we want and it is also not intentional, but the result of how detailed things can these days be controlled in XXHighEnd.

It is also why Mani asked me, because this is not allowed to happen. It really goes unnoticed when it happens BUT changes the sound.

 

Apologies if this is confusing.

 

Thanks for the explanation. Of course, high precision timers are available and should be used (for example, the HP counter on my audio PC, built about 4 years ago, has the frequency of 14.3 MHz).

 

But, that's exactly why digital output of the PC should be recorded and compared. If samples are unexpectedly dropped due to bandwidth,  processing, or other hardware limitations, this can affect the sound differently for different sources by changing actual samples being sent to the DAC.

 

[pkane2001]

1 minute ago, mansr said:

You don't need high precision timers to play back audio. In fact, you don't need timers at all.

 

Probably not, but I'm not the one who brought up timer precision -- Peter did, and he's the author of the software and the DAC that will be used in this test, so I defer to him on what XXHighEnd is using.

 

[pkane2001]

3 minutes ago, mansr said:

If I become convinced there's a difference, I will certainly attempt to figure out why.

 

And that's why Mans is such a good test subject for this: he'll be curious enough to dig in deeply to find the reason for audible differences (if any), and he'll collect enough data and evidence so that others could help him, right, Mans?

 

[pkane2001]

5 hours ago, Audiophile Neuroscience said:

What may or may not be stressful to you may be quite different for others.

 

Take the little blue pill if you're experiencing performance anxiety (how about that, back on-topic for this thread! )

 

 

[pkane2001]

Just now, Audiophile Neuroscience said:

 

Agreed, performance anxiety is on topic and will affect us all differently. That is why I asserted that just because someone does not find a test stressful doesn't mean others will not. I do agree Mani offered the 'challenge' so one would think he is not stressed by the scenario. However, as said, the caveat as to not feeling stressed is that it should stay close to how Mani offered it.That's not to say others' suggestions are not valid.

 

A joke is not funny if you have to explain it, so I'll resist.

 

[pkane2001]

6 minutes ago, manisandher said:

I can't tell you how pissed off I am that the things we've discussing in this thread exist at all. I would absolutely love it to be the case that I could use whichever source, whichever software player, whichever cable, whichever interface, and for there to be no change in the sound. I would rejoice like you couldn't imagine.

 

Hold off until you do the blind test with Mans, maybe you'll be rejoicing after all

 

[pkane2001]

1 minute ago, beerandmusic said:

Here is another review I just read about the Altair that suggests different interfaces sound different....

 

More observations

4. Wireless sounds better than wired: I don't know why or how, but wireless just sings a different tune. When wired, I hear the same kind of cleanliness/etch with less bass and more flatness with the SOtM I had. I guess I like it dirty.

5. Tidal sounds inconsistent: Not related to Auralic, but some files from Tidal sound different compared to my ripped files. Just trying it out for a month, but so far not impressed.

 

I suspect this is all expectation bias-driven. Having gone through multiple tests of Wi-Fi -> USB -> DAC, Ethernet -> USB -> DAC, USB directly, and USB over Ethernet -> DAC, I can't tell the difference between them unless there's not enough bandwidth. The playback is then obviously interrupted with clicks and drop-outs if there's not enough bandwidth or large latency. I've finally settled on USB over Ethernet, but this is because I needed to move my audio PC into the adjacent room, with about a 25m ethernet cable.

 

[pkane2001]

3 minutes ago, Audiophile Neuroscience said:

33 minutes ago, pkane2001 said:

I suspect this is all expectation bias-driven. 

 

So this is what this test with Mani and Mansr is all about IMO.

 

Yes!

[pkane2001]

8 hours ago, Audiophile Neuroscience said:

To clarify; my comment "So this is what this test with Mani and Mansr is all about IMO. " was aimed at you not being able to hear differences.

 

Expectation biases may or may not come in to it but either way should be controlled for.

 

There are two participants in this test, and their aims are not the same.

 

And by the way, I've been in Mani's shoes for many years. Spent a ton of money on digital clean-up equipment, cables, etc. Until I decided to seriously test what I was hearing. I've done the proposed blind test many times over, and no, personally I can't hear the difference.

 

I'm fully open to Mani proving his point. And if he does, just like Mans, I'd like to try to understand what caused the audible differences even if PeterSt thinks that's impossible to figure out. An objective outcome, positive or negative is something I would welcome, unlike all the subjective reports that dominate this topic.