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post #41 of 48
Quote:
Originally Posted by Rob55 View Post

Out of curiosity, would you mind providing some additional details about your double-blind tests? I know you're using Foobar and the ABX component, but what about the hardware? I'm genuinely interested to know.

I haven't used foobar personally. I did sighted comparisons between my iPod playing compreesed tracks vs a CD player playing the originals. My pre-amp is a Meridian 201 and allows for inputs to be volume matched. I would cue up the devices so they were playing the same track in sync time-wise, as much as possible, then used the remote to switch between sources. For moderate to high compression rates i couldn't hear a difference. Thinking my hearing was possibly not that great, I got others to listen also, they couldn't hear a difference either.

Equipment used: iPod classic 3rd gen, Micromega stage 2 CD player, Meridian 201 pre-amp, Perreaux 6000B amp, B&W 802 Nautilus speakers.

I have also used Sony MDR-D77 headphones.

In response to HiFi critics, I created a file containing interleaved segments of 223 kbps AAC and uncompressed source, which I uploaded. This doesn't require Foobar or anything else special for playback. I ask people to tell me the time codes where the edits are. No one has so far. Here is the file if you are interested: https://rapidshare.com/files/3023221...3AAC_short.rar

Foobar is a better approach, but requires a PC or windows.
post #42 of 48
I'm with cnocbui

I believe most of the people ranting about "lossy" music couldn't pick out an uncompressed song from a 256kb AAC version with anything but 50/50 odds.

Though if someone is willing to try here's a great app that will help you fail like so many others have done lol

http://itunes.apple.com/us/app/abxte...27554135?mt=12

Looks like the new Apple format is really HD-AAC finally coming to market

http://www.iis.fraunhofer.de/en/bf/a...ocodecs/hdaac/
http://en.wikipedia.org/wiki/MPEG-4_SLS
He's a mod so he has a few extra vBulletin privileges. That doesn't mean he should stop posting or should start acting like Digital Jesus.
- SolipsismX
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He's a mod so he has a few extra vBulletin privileges. That doesn't mean he should stop posting or should start acting like Digital Jesus.
- SolipsismX
Reply
post #43 of 48
Quote:
Originally Posted by cnocbui View Post

I haven't used foobar personally. I did sighted comparisons between my iPod playing compreesed tracks vs a CD player playing the originals. My pre-amp is a Meridian 201 and allows for inputs to be volume matched. I would cue up the devices so they were playing the same track in sync time-wise, as much as possible, then used the remote to switch between sources. For moderate to high compression rates i couldn't hear a difference. Thinking my hearing was possibly not that great, I got others to listen also, they couldn't hear a difference either.

Equipment used: iPod classic 3rd gen, Micromega stage 2 CD player, Meridian 201 pre-amp, Perreaux 6000B amp, B&W 802 Nautilus speakers.

I have also used Sony MDR-D77 headphones.

In response to HiFi critics, I created a file containing interleaved segments of 223 kbps AAC and uncompressed source, which I uploaded. This doesn't require Foobar or anything else special for playback. I ask people to tell me the time codes where the edits are. No one has so far. Here is the file if you are interested: https://rapidshare.com/files/3023221...3AAC_short.rar

Foobar is a better approach, but requires a PC or windows.

While it's clearly true that many people don't have the most ideal hearing and that less than ideal equipment can further obfuscate higher quality audio what you've presented isn't enough information to determine if 223kbps AAC lossy is just as good as an uncompressed source because you have qualified the quality of the original source.

We see this all the time. It's uncompressed or its FLAC or ALAC. These mean nothing without knowing the quality. It's possible that someone who wanted to create a false test — not an implication, just an extreme example to get my point across — could take a 128kbps AAC "lossy" file and then re-encode it to ALAC "lossless" and then have people compare. Both files should sound identical with the only variances being in how they processed which should in be negligible in every way.

For a real test we need not just certified equipment that can handle quality audio from it's point of origin to your ears but also content that has is known to have come from a high quality source.

I've heard demos between CD and SACD and it was night and day. Of course, they used different equipment and could have adjusted the controls so I can't rule out shenanigans but I can't rule out that 1 bit DSD, 2.8224 MHz, 120 dB, 20 Hz – 50 kHz audio isn't better than and more discernible than 16 bit, 44.1 kHz, 96 dB, 20 Hz – 22.05 kHz audio.

"The real haunted empire?  It's the New York Times." ~SockRolid

"There is no rule that says the best phones must have the largest screen." ~RoundaboutNow

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"The real haunted empire?  It's the New York Times." ~SockRolid

"There is no rule that says the best phones must have the largest screen." ~RoundaboutNow

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post #44 of 48
Quote:
Originally Posted by hmurchison View Post

Looks like the new Apple format is really HD-AAC finally coming to market

http://www.iis.fraunhofer.de/en/bf/a...ocodecs/hdaac/
http://en.wikipedia.org/wiki/MPEG-4_SLS

Thanks for those links. I read more on HD-AAC on Fraunhofers' site here. Very interesting article.
post #45 of 48
Quote:
Originally Posted by Sevenfeet View Post

And of course, there's still some vinyl out there.

Vinyl sales were indeed up, 39% actually. Though it apparently only sold 4M WW
http://www.economist.com/node/21526296
post #46 of 48
Quote:
Originally Posted by SolipsismX View Post

While it's clearly true that many people don't have the most ideal hearing and that less than ideal equipment can further obfuscate higher quality audio what you've presented isn't enough information to determine if 223kbps AAC lossy is just as good as an uncompressed source because you have qualified the quality of the original source.

We see this all the time. It's uncompressed or its FLAC or ALAC. These mean nothing without knowing the quality. It's possible that someone who wanted to create a false test not an implication, just an extreme example to get my point across could take a 128kbps AAC "lossy" file and then re-encode it to ALAC "lossless" and then have people compare. Both files should sound identical with the only variances being in how they processed which should in be negligible in every way.

For a real test we need not just certified equipment that can handle quality audio from it's point of origin to your ears but also content that has is known to have come from a high quality source.

I've heard demos between CD and SACD and it was night and day. Of course, they used different equipment and could have adjusted the controls so I can't rule out shenanigans but I can't rule out that 1 bit DSD, 2.8224 MHz, 120 dB, 20 Hz 50 kHz audio isn't better than and more discernible than 16 bit, 44.1 kHz, 96 dB, 20 Hz 22.05 kHz audio.

re SACD: It is known that some SACD releases involved re-mixing and mastering so it would not be surprising if there was an audible difference in some cases.

A fundamental Psychoacoustic principle is that, all else being equal, if there is a volume level mismatch between two samples, test subjects will report the louder one as being of higher quality. So your night and day SACD experience could be simply down to loudness. The tests I have done have involved care and attention to level matching using white noise, for just this reason.

The source of the file I created was a wav rip from a commercially produced CD so it was 44.1khz 16 bit. No need for 'higher' quality than that as double blind trials indicate the difference isn't audible. The CD in question was Hybrid - Dissapear Here. Now if I can extrapolate from the tenor of your arguments, you might next claim the original production values of the CD are below par and thus invalidate the source. Given hybrid bothered to hire the Prague Symphony orchestra, I think it wouldn't be too big a stretch of logic to assume they care about sound quality and the production values might reflect that. In my opinion that is the case, which is why I picked it as a source. Here they are recording a track: http://www.youtube.com/watch?feature...v=wEz4gnVYoyk#!

I could have stuffed it up on purpose but will state publicly I didn't. I don't need to.

Double blind trials involving many people and many different music samples have been conducted for years at Hydrogen Audio. The results are scientific and near indisputable. See if you can explain away the results of the public listening tests contained in these threads: http://www.hydrogenaudio.org/forums/...p?showforum=40
post #47 of 48
Quote:
Originally Posted by cnocbui View Post

In response to HiFi critics, I created a file containing interleaved segments of 223 kbps AAC and uncompressed source, which I uploaded. This doesn't require Foobar or anything else special for playback. I ask people to tell me the time codes where the edits are. No one has so far. Here is the file if you are interested: https://rapidshare.com/files/3023221...3AAC_short.rar

Foobar is a better approach, but requires a PC or windows.

Thanks for the info. At least we've established that there's no weak link in your playback system. That said, I gave your file a listen and will readily admit that it's impossible to tell where your edits are. Of course, I listened to the file here at work via my MBP using iPhone earbuds which are far less than ideal for this test. However, being completely unfamiliar with the song, it's virtually impossible to tell because I literally don't know what I'm missing. As you say, Foobar is a better approach due to the A/B nature of the comparison, not listening to (for example) the 1st minute of the uncompressed source, then then next 30 seconds of the song from a compressed file, back to the next 30 seconds from the uncompressed source and so on. Back in the day when I was in high-end audio, critical listening always involved listening to the same passage or song over and over again with multiple configurations. Granted, back then we were typically comparing one tube amp to another or one DAC to another etc..., but the principal is the same. I'll try an outboard audio interface with my MBP at home with a proper set of headphones and I'll see if I can hear any difference then (which I doubt).
post #48 of 48
Thanks for having an honest listen.
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