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High Bitrate/sample rate lossless codec tests

Reply #25
.. a lack of substantiated testing as opposed to accepting someones word.

ABX testing

I'm not one for repeating what's already been said but, if there's a difference between lossless codecs, something is broken in the playback chain.
daefeatures.co.uk

High Bitrate/sample rate lossless codec tests

Reply #26
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Just because you didn't hear it, doesn't mean it didn't happen.

Sorry, its up to you prove it did happen. Otherwise you get all sorts of unverifiable blue elephant theories.

If bit-by-bit comparison is not good enough for you, then you actually are claiming that a file is never the same twice. (since a file is always bit-identical with itself). If that is the case, any listening test would be unusable as results would never be reproducable.

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I agree in many respects audio reproduction is a science, but it cannot be overlooked that it is also an art.

That's just being romantical, and unfortunately not really to the point here. Does an English book report about George Orwell's 1984 written in Word change into a report about Shakespeare's Hamlet after zipping and unzipping it? You might not have seen it, but that doesn't mean it isn't possible, right?
"We cannot win against obsession. They care, we don't. They win."

High Bitrate/sample rate lossless codec tests

Reply #27
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Just because you didn't hear it, doesn't mean it didn't happen.

Of course not. But we're in a world ruled by Intel and AMD, not by Gandalf and Harry Potter. If files are bit-to-bit perfect, most people won't see any reason to worry with listening investigation about possible but irrational difference.

But as I said, you're free to investigate and perform your own listening tests between lossless encoders, even if it sounds useless to most people. And when this task will be over, and if you're still interested by possible sound degradation, I've other very useful suggestions:

- which hard drive brands produce the best quality? Some friends told me that sound is warmer with Hitachi, but that MP3 have more soundstage with Maxtor.
- the influence of computer's supply on stereophonic image. Is sound better with 300W or should we switch to 480W power supply? Your experience is welcome.
- AMD or Intel for better bass response?
- which CD-Rom brand for better extraction? Are really Plextor giving a better accuracy to high frequencies content?
- and what IDE cable are the warmest?

A sceptical person, interested to compare lossless files sound quality, should test every components of his computer.

High Bitrate/sample rate lossless codec tests

Reply #28
I do agree with guruboolez. Let us put several things straight:

Bit-by-bit perfect means just that: The copy is exactly the same.

Does it sound the same? Yes, it should.

So why doesn't they sound the same? Let's see here:

1. Different decoders. Especially with lossy codecs, different decoders will cause different waveform reproduction. Some good, some bad. With lossless codecs, the reproduced waveform must be the same. If not, then the decoder is buggy.

2. Different sound reproduction equipment. I do believe that Umatic tape player and CD player are 2 different equipments. Most likely both use different audio waveform generation chips, and thus will produce differing audio signals. Not to mention the signal path taken through the output circuitry of both players.

If we are rigorous in testing, ensuring that every darn sound reproduction equipment is exactly the same, and also ensuring that the playback environment (e.g. power supply, ambient noise, psychological mood, etc) then 2 bit-by-bit identical WAV files must sound the same.

Ambient noise we can control. So can we control power supply. The one thing we cannot control is the psychological mood.

So, how can we ensure fair and objective test? By using an anechoic chamber with high-fidelity mics to re-record the output of the speakers, as WAV files. Also allow several minutes between 2 WAV files to let the chamber settle.

We repeat the test the next day at the exact same time, but this time we reverse the WAV sequence.

Then we compare the result bit-by-bit but with tolerance to allow for noise in the cables.

Outrageous? Yes. But in my opinion, it is the only way to conclusively proof the difference between lossless codecs.

And I think I already know the result.

High Bitrate/sample rate lossless codec tests

Reply #29
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- AMD or Intel for better bass response?

At least on AMD X2, audiophiles should avoid running two lossless encodings at the same time, because there will be quite high intermodulation distorsion between them..

AMD is working on a new CPU stepping with better shielding between cores, to reduce the interference.

For the time being, better use lower frequency CPUs (up to 400 MHz) for the best sound..
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- and what IDE cable are the warmest?
[a href="index.php?act=findpost&pid=353020"][{POST_SNAPBACK}][/a]

In other news, cheap SATA cables have been reported to give a subtle, but very disturbing metallic timbre to the sound..

High Bitrate/sample rate lossless codec tests

Reply #30
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no one has actually LISTENED or has made comparisons

Ok. Normaly to make double-blinded comparisons the two files are decoded to random wavs and them you listen trying to find diferences. But in the folder you have two identical wav files, with only diference is the name. I think that is simple too dumb to me try to find diferences between two identical files/waveforms.... But you is free to do what you want. You can even try to start an listening test, but I doubt you would have many voluntary and I doubt even more that they can find diferences between the files.

High Bitrate/sample rate lossless codec tests

Reply #31
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AMD is working on a new CPU stepping with better shielding between cores, to reduce the interference.


no shit? 

High Bitrate/sample rate lossless codec tests

Reply #32
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AMD is working on a new CPU stepping with better shielding between cores, to reduce the interference.


no shit? 
[a href="index.php?act=findpost&pid=353061"][{POST_SNAPBACK}][/a]

Yes, and it will use water gates instead of transistors, thus removing all electrical interference. The basic material was discovered in deep sea in the 80's by Commandant Cousteau and his team.

I'm testing an early prototype of it in my bathroom; the only problem is when a calculation overflows, the water overflows too 

High Bitrate/sample rate lossless codec tests

Reply #33
I feel tired.

High Bitrate/sample rate lossless codec tests

Reply #34
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Doing listening tests for lossless codecs is a futile idea. If there were any differences it would most likely have to do with the decoder and not the file itself. Lossless files are identical to the original waveforms when decoded.

I don't know about DTS v.s. MLP, but I'm sure someone here might be able to give you a rundown or you could try a google search on the subject.

MusicGiants offers WMA DRM Enabled Lossless files. The files are not all 1080kbps, that's probably an average or something. When they say they are lossless they mean that only unnecessary information is discarded. All of the original coded file can be rebuilt without losing information from a decoded lossless file. And IIRC Redbook CD Audio is 1411kbps.
[a href="index.php?act=findpost&pid=352753"][{POST_SNAPBACK}][/a]
Actually, CD is 1411.2 kbps / 1411200 bps.

High Bitrate/sample rate lossless codec tests

Reply #35
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Actually, CD is 1411.2 kbps / 1411200 bps.
[a href="index.php?act=findpost&pid=353080"][{POST_SNAPBACK}][/a]

which is obtained by multiplying:
44.1 [kHz] * 16 [bit] * 2 = 1.4112 [Mbit/s]

High Bitrate/sample rate lossless codec tests

Reply #36
man, i'm always taking things too seriously 

High Bitrate/sample rate lossless codec tests

Reply #37
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man, i'm always taking things too seriously 
[a href="index.php?act=findpost&pid=353097"][{POST_SNAPBACK}][/a]

Where's zen-infinity hiding now?  Any more arguments to distract us from 'science' ?

High Bitrate/sample rate lossless codec tests

Reply #38
@Shade[ST]

bad for him we don't have 1990 anymore. i could hear my hd through the speakers.

 
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