Mega Lossy v Lossless Test

[jcbrum]

... the AAC has been re-converted to WAV: a necessary practicality to keep the test blind, ... However, this has leveled the difference somewhat ... the upsampled-to-WAV AAC will perform better than the AAC left in its compressed form.

I don't think you understand what is occurring here. - compression, lossy or lossless, has nothing at all to do with up-sampling, down-sampling, or re-sampling.

There is no reason why the bit-resolution and sampling rate cannot remain constant throughout all the examples.

... real-time decompression during playback results in audible degradation.

Oh no it doesn't.

Audio is an undemanding task for computers. They can easily uncompress video on-the-fly for example, which is far more demanding, and still have lots of redundant cpu power in hand.

JC

 

[hubsand]

Do you actually read posts?

I said quite clearly that higher standards are useful for professional recording and processing. I am saying that 16 bit is good enough for home replay. The requirement for recording and mastering can be quite different to home replay.
I am also not saying that people should 'squash' 16 bit as you claim.
This test is about assessing the ability to hear lossy compression and it has nothing to do with how people store their music collection. Once again you are arguing with yourself.

On the adequacy of 16/44, test after test in frotn of listeners will confirm it, so no I'm not making a judgement on behalf of humanity I''m basing the comments on real observed experience.

Visit the Audiosmile room at the National show.
I'll put some high quality vinyl through a 16/44 ADC/DAC loop for you (blind).
See if you can spot the 'inadequate' processing......... if so you'll be the first.

Unless I'm mistaken, I appear to be arguing (politely) with you. Like this:

No, no, no. No. For starters, why different standards for home and pro? The aim of reproduction fidelity is identical, and there's increasing convergence between 'domestic' and 'professional' technology: it always was an arbitrary distinction.

The goal of the poll appears to be to 'demonstrate' that high-ish bit-rate AAC compression is as near as makes no difference identical to lossless 16/44.1.

If that were true, the inevitable conclusion is that listening to, owning and storing something as 'good' as 'CD quality' is pointless: compress and be damned. That could mislead a newbie computer audio adopter into a costly mistake: one in which they end up re-ripping thousands of CDs - like I did a few years ago.

Of course, without context, you can wow someone in an audition with an MP3, or a well recorded RedBook. And the wow factor would be doubled by playing the same file in uncompressed 24 bit. Because it's just much better - for all the same reasons that AACs are worse.

For maximum listening pleasure, keep the compressed music in the car and on the 'phone. And please release studio masters for download so we can hear digital done right: it's been impugned in too many turntable shoot-outs recently!

 

[hubsand]

I don't think you understand what is occurring here. - compression, lossy or lossless, has nothing at all to do with up-sampling, down-sampling, or re-sampling.

There is no reason why the bit-resolution and sampling rate cannot remain constant throughout all the examples.




Oh no it doesn't.

Audio is an undemanding task for computers. They can easily uncompress video on-the-fly for example, which is far more demanding, and still have lots of redundant cpu power in hand.

JC

My goof: lazy use of 're-sampling'.

The issue re: decompression isn't about whether the processor can unpack on-the-fly, it's whether it can do so without introducing audible jitter. Or maybe there's another cause.

It's well attested that uncompressed files perform better than FLACs and ALACs: if you can't hear it for yourself, draw up a list of those fall on both sides of the fence and see where the expertise lies . . .

Ideally, we might audition the Danse Macabre track in an AAC file, back to back with the same file converted to WAV (assuming the conversion process itself isn't upwardly lossy).

 

[hubsand]

I think you are clutching at straws.
Decompression with current processors is a trivial matter as can be demonstrated with a tiny MP3 portable player costing perhaps £30.

What you are suggesting would only apply to extremely poor/old equipment.

I could equally argue that the AAC should sound even worse because it has been through another process by converting it back to WAV. I won't because that would be clutching at straws.

The output files could be bit-matched: it would be interesting to know if/how the process is lossy.

MP3 players are a great example of a device that thrives on not having to decompress during playback. Try it.

If, at the same time, you get to audition a Nano vs a Touch iPod, that might be an ear-opener, too.

 

[Basil]

It's well attested that uncompressed files perform better than FLACs and ALACs: if you can't hear it for yourself, draw up a list of those fall on both sides of the fence and see where the expertise lies . . .

Total nonsense.

You really need to do some reading about flac and lossless.

 

[RobHolt]

The goal of the poll appears to be to 'demonstrate' that high-ish bit-rate AAC compression is as near as makes no difference identical to lossless 16/44.1.

If that were true, the inevitable conclusion is that listening to, owning and storing something as 'good' as 'CD quality' is pointless: compress and be damned. That could mislead a newbie computer audio adopter into a costly mistake: one in which they end up re-ripping thousands of CDs - like I did a few years ago.

Your first point is correct, and the blind listening would tend to support the view.

Your conclusion is precisely that - yours.
I've not argued that people should store their music collection as MP3 or AAC and in fact recommend that people use lossless, be it FLAC or Apple. I do so primarily to preserve the data for future developments that might emerge.

This test is concerned with listener perception and nothing more.

The only misleading is the attempt to convince listeners that they need better than 16/44 for their home audio, and the equipment to reproduce it.
I can demonstrate (blind) in a minute or so that they dont.

So come along on the 25th and see if you can detect real time on-the-fly 16/44 encode/decode.

 

[Labarum]

So come along on the 25th and see if you can detect real time on-the-fly 16/44 encode/decode.

Is that using vinyl as the analogue source, or have I mis-read a previous post, Rob?

A studio quality analogue master tape would be the more demanding test, would it not?

 

[RobHolt]

Is that using vinyl as the analogue source, or have I mis-read a previous post, Rob?

A studio quality analogue master tape would be the more demanding test, would it not?

It would, but not something I can sort.

I do have a few 24 bit 'audiophile' recordings though and can truncate those down to 16/44.

 

[jcbrum]

I did this test 6 or 7 years ago for a doubting dealer. He supplied the studio quality master tape and the tape machine, and I simply inserted an adc/dac process via a switchable link.

He couldn't tell which was playing, - the raw analogue output or the adc/dac chain.

We repeated the test with a very highly modified pink triangle/origin vinyl deck with a similar result.

There is no audible difference with good equipment which is properly set up.

 

[hubsand]

Total nonsense.

You really need to do some reading about flac and lossless.

Reading like this, you mean?

http://forums.linn.co.uk/bb/archive/index.php/thread-817.html
http://forums.linn.co.uk/bb/archive/index.php/thread-5138.html
http://www.usbdacs.com/Macintosh/Macintosh.html (Gordon Rankin)
http://www.computeraudiophile.com/faq
http://www.computeraudiophile.com/content/AIFF-or-Apple-Lossless
http://forums.slimdevices.com/showthread.php?t=71321
http://www.head-fi.org/forum/thread/366271/flac-vs-wav-format-surprising-quality-differences
http://www.audioasylum.com/cgi/t.mpl?f=pcaudio&m=61262
http://www.empiricalaudio.com/computer-audio/
http://www.thewelltemperedcomputer.com/KB/WAV-FLAC.htm

. . . as the tip of the iceberg.

Typically, you find two responses to this question: the ignorant one, from people who haven't bothered to audition for themselves. And the informed one, from people who have open-mindedly listened using a top-notch system. Many of the second group have found for themselves there is an audible difference. Not as gross as the presence of compression artifacts, but definitely there. Why not try it?

It would be helpful to hear the the original AAC back-to-back with the WAV'd version.

 

[hubsand]

Your first point is correct, and the blind listening would tend to support the view.

Your conclusion is precisely that - yours.
I've not argued that people should store their music collection as MP3 or AAC and in fact recommend that people use lossless, be it FLAC or Apple. I do so primarily to preserve the data for future developments that might emerge.

This test is concerned with listener perception and nothing more.

The only misleading is the attempt to convince listeners that they need better than 16/44 for their home audio, and the equipment to reproduce it.
I can demonstrate (blind) in a minute or so that they dont.

So come along on the 25th and see if you can detect real time on-the-fly 16/44 encode/decode.

What a strange double standard: why rip huge lossless files if small lossy ones sound exactly the same to you?

What mysterious 'future developments' could change that - if, as you seem to argue, it's beyond the wit of man to differentiate lossy from lossless?

I maintain that anyone with half decent hearing, a good listening environment and a 60 second primer can do so now.

It's pointless to attempt fine-grained distinctions in the compromised and unfamiliar environment of an audio show: that's not what they're for!

 

[Basil]

Nothing in those links to change my mind, no logs from blind ABX tests where the flac file has been correctly identified.

Just the usual audiophool nonsense from people who don't understand how computers work.

 

[Mescalito]

Nothing in those links to change my mind, no logs from blind ABX tests where the flac file has been correctly identified.

Just the usual audiophool nonsense from people who don't understand how computers work.

Hear, hear.

What is it about hi-fi which attracts such a large percentage of the gullible and the slf-delusional.

Is there any other hobby where this happens to such an extent?

Chris

 

[jcbrum]

Nothing in those links to change my mind, no logs from blind ABX tests where the flac file has been correctly identified.

Just the usual audiophool nonsense from people who don't understand how computers work.

Agreed, ....... just a load of assertions from people with neuroses about their hearing.

Assertions aren't anything more valuable than claims that the Moon is made from cheese.


JC.

 

[Mescalito]

What a strange double standard: why rip huge lossless files if small lossy ones sound exactly the same to you?

What mysterious 'future developments' could change that - if, as you seem to argue, it's beyond the wit of man to differentiate lossy from lossless?

I maintain that anyone with half decent hearing, a good listening environment and a 60 second primer can do so now.

It's pointless to attempt fine-grained distinctions in the compromised and unfamiliar environment of an audio show: that's not what they're for!

How come, whenever the faithful are challenged to participate in any kind of put-your-money-where-your-mouth-is evaluation there are always excuses to explain why it would be pointless?

The kit isn't revealing enough, the test is too stressful, etc,etc.

Chris

 

[RobHolt]

What a strange double standard: why rip huge lossless files if small lossy ones sound exactly the same to you?

What mysterious 'future developments' could change that - if, as you seem to argue, it's beyond the wit of man to differentiate lossy from lossless?

I maintain that anyone with half decent hearing, a good listening environment and a 60 second primer can do so now.

It's pointless to attempt fine-grained distinctions in the compromised and unfamiliar environment of an audio show: that's not what they're for!

Oh dear.

I'll say it again for you.

This test is concerned solely with establishing the ability to differentiate lossy from lossless. It has nothing to do with storage which, as you say, is plentiful and cheap.

As Simon has said to you repeatedly, the comments of those spouting the ability to clearly hear these differences yet not participating in the tests are best ignored since they are completely hollow.

As for the show, if the conditions bother you then stick around and do the test at the end of the day.

 

[hubsand]

The issue of whether compression induces audible degradation (like SATA cables!) is still hotly debated, but time will tell.

Look how things have progressed in recent decades: someone pops up and claims that factor A makes an audible difference: cue knee-jerk lambasting from the 'experts' for being such an idiot . . . then over time everyone jumps on the bandwagon: capacitors, speaker cable, analog interconnects, power cables, digital cables, cryo-treatment, RFI/EM shielding . . . it all matters: in time, all these 'snake-oil' upgrades get incorporated in products by manufacturers who know they work better.

Already five year old forum threads preaching the invincibility of the computer and soundcard look archaic. Make sure this one is archived!

 

[Tenson]

SATA cables sound different to each other? I hope you are joking

 

[Labarum]

SATA cables sound different to each other? I hope you are joking

Of course they all sound different: stretch them across the bridge of a cello or double bass and pluck them, they don't bow so well, but they all sound different. Night and day!

Put them in the deep freezer overnight and they sound different again, but be careful the plastic insulation doesn't shatter - it gets quite brittle at -18C.

Don't you folks all know this?

 

[RobHolt]

The issue of whether compression induces audible degradation (like SATA cables!) is still hotly debated, but time will tell.

Look how things have progressed in recent decades: someone pops up and claims that factor A makes an audible difference: cue knee-jerk lambasting from the 'experts' for being such an idiot . . . then over time everyone jumps on the bandwagon: capacitors, speaker cable, analog interconnects, power cables, digital cables, cryo-treatment, RFI/EM shielding . . . it all matters: in time, all these 'snake-oil' upgrades get incorporated in products by manufacturers who know they work better.

Peter Walker nailed what should be the desired attitude towards cables many decades ago.

'They should be of sufficient length in order to reach the components and of appropriate colour to match the room decor' - or wording very similar.