Thank you John,

That is a very clear and concise explanation of lossy versus lossless codecs. While the loss of musical information by the creation of a lossy file is quite disturbing there is additional danger when it comes to lossy files. By this I'm referring to this scenario: someone (legally) downloads an album from iTunes (which would be in Apple's lossy codec), burns those files to an audio CD, lends the audio CD to a friend who then rips the files onto their computer but as mp3 files. So now, without the music ever leaving the digital domain (where the sound is perfect ) one has created a file which has gone through the following conversion steps:

1) Original wav file into apple lossy file (loss of data)

2) apple lossy file back into wav file (to make the audio CD) but not the same wav file as the original file. (I don't know if there is data loss in this step)

3) new wav file into mp3 file (more and different data loss)

Sure it's digital but it's not the same digital as when it started.

Of course with a lossless codec there would be no data loss regardless of how many steps are involved. Just some food for thought.

Thanks JA. I just forwarded your re-issued comments to my 21 year old daughter. Of course, she's iPod-generation and she's now upset that she "wasted" a bunch of money on mp3 downloads that she has suddenly realized sound like crap.

She was stunned when we exchanged iPhones for a while and my music sounded so good. She asked, "Is it because you ripped them all from CDs" and I said, "No, it's because I used lossless." Of course, I can only get about 20 albums on the first generation 8GB iPhone, but at least I've got something worth listening to.

It's also interesting to note that she's moving into better gear. She sent me a text yesterday day asking me "what are those really great headphones you use?" (AKG K701s and Ultimate Ears Triple.fi 10 Pros). I explained how the 701s really need a good, separate headphone amp, but the UEs are great right out of an iPhone and UE is now making an iPhone-model, with built in mic and the correct mini-plug.

I'm active over head-fi.org and it's clear that there are many very serious new audiophiles in their late teens and twenties seriously getting the audiophile bug, but starting with headphones. They start with iPod, iPhones, Zunes, etc. into earbuds, then graduate to IEMs, then add a portable amp. Next thing you know they're spending $200 to $700 on AKGs, Sennheisers, Grado, Beyerdynamic, Audio Technica, etc. cans, then adding a desk top amp, then moving to a single-ended tube amp, electrostatic cans. Before you know it, they're asking about speakers and how to fit a nice 2-channel rig into a teeny apartment.

I'm well aware of Stereophile's admirable and long history of reviewing high end headphones. A good project within the next year or so might be to survey the headphone culture and give a brief survey of the most popular cans and IEMs.

Just a thought. You guys do a great job and I appreciate you diving in here occasionally to keep us on track. I know that you must tread carefully.

Dave

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She was stunned when we exchanged iPhones for a while and my music sounded so good.... It's also interesting to note that she's moving into better gear.

This is all so great to hear, Dave.

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Of course with a lossless codec there would be no data loss regardless of how many steps are involved. Just some food for thought.

You raise an important issue. The audio engineering community is well aware of the problems of cascading lossy codecs, because lossy coding is used extensively in the broadcast industry. You only need to cascade 2 or 3 different codecs operating at different bit rates for all the psychoacoustic assumptions made for each codec on its own to fail catastrophically with respect to sound quality!

I may well address more of Struts' points individually, but to look at one your points:

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apple lossy file back into wav file (to make the audio CD) but not the same wav file as the original file. (I don't know if there is data loss in this step)

There isn't data loss in the conversion back to WAV, but the WAV file _is_ degraded compared with the original. And when _this_ WAV file is used as the source for another lossy codec, even if it is the original one used, because the splitting into time chunks for analysis will not coincide with the original splitting, transient information gets even more smeared in time.

John Atkinson
Editor, Stereophile

Dave,

I also have two daughters, 22 and 20 years old. The younger one may well be a lost cause when it comes to understanding and caring about good sound but the older one gives me hope. At the present time my wife and I are about six months into an eighteen month stay in the Netherlands. My older daughter is living in and taking care of our house back in the USA. Within that house is my main stereo system, which I did not take with me since my Vandersteens are much too big for the apartment we are living in and my power amp runs on 120 volts not 220 volt. Anyway, here's something she wrote to me earlier today:

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i just had to tell you that i was listening to "the dead heart" on my computer and realized i needed to stop and go blast it on your stereo because my speakers can't do that song justice. i also blasted "beds are burning."

....because you always pick out good music to blast. and mommy because it's funny how it annoys her because it's so LOUD! but we just sit there and enjoy it.
i also wanted to let you know the vandersteens are getting lots of good use....so far: donna the buffalo, k.d.lang, lyle lovett, john haitt, sopranos soundtrack...and that's all within this past week. making dinner and blasting music has been my thing.
and now i've got judybats on my computer so i might go blast that while doing the dishes.
i'm totally your daughter, if you haven't noticed.

"The Dead Heart" and "Beds Are Burning" are two songs by the group Midnight Oil in case you're wondering. So I think that my daughter is beginning to understand what good sound is all about and who knows maybe she'll give up the BIG wedding in exchange for a good stereo. At today's prices even a Linn/Krell/Wilson system would be less than the cost of a big Italian-American wedding.

Now if I could just convince her to listen to some Miles Davis or John Coltrane. Oh well, I can always hope.

John,

Thanks for the comprehensive response. Although I was an avid Stereophile reader at the time, your treatment of mp3 significantly predated my interest in computer audio so I missed a lot of this discussion first time round. I had a rough idea what was going on with mp3 but the detail is fascinating.

I would like to take issue slightly with one point though:

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The only difference between data and audio lossless compression is that the latter allows for random access within the file.

which I believe ignores some of the significant features of and therefore differences between, lossless audio codecs (and by extension the difference between lossless audio codecs and lossless general purpose codecs).

Features such as asymmetry, i.e. the encode speed/decode speed trade-off are particularly important in near-real time applications like audio reproduction. For instance I believe FLAC is designed in such a way that decompression only requires integer math making it possible to decode faster and/or on devices with less powerful processors. This is probably a less important consideration when compressing a word file!

Similarly streaming support, the ability to decode the start of the file before you have received the end (maybe that is what you refer to as 'random access'?) is sometimes very useful in audio applications. I don't believe that ZIP supports this.

In fact this very helpful chart compares lossless audio codecs on no less than 18 different parameters, many of which are uniquely relevant to audio applications.

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I

This is a pretty kewl blast from the past, brought to us by none other than JA of Stereophile, in 2001.

Linn Knekt Kivor hard-disk multizone music system

Shew, that's a mouthful. Worth a read. We've come a long way baby.

RG

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This is a pretty kewl blast from the past, brought to us by none other than JA of Stereophile, in 2001.
Linn Knekt Kivor hard-disk multizone music system

A long time ago, that was. (Damn, the Yoda-speak problem, I have still got, hmmm?)

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Worth a read. We've come a long way baby.

Have, we. Yes.

John Atkinson
Editor, Stereophile

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I would like to take issue slightly with one point though:

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The only difference between data and audio lossless compression is that the latter allows for random access within the file.

which I believe ignores some of the significant features of and therefore differences between, lossless audio codecs (and by extension the difference between lossless audio codecs and lossless general purpose codecs).

Point taken, I didn't mean to say that was the only difference. But for me it is the _primary_ difference between general-purpose zipping programs and dedicated audio lossless compression codecs. If you had to wait to unzip the complete 500MB file before you could play it, you would rapidly abandon the whole idea (and maybe reach for an LP).

John Atkinson
Editor, Stereophile

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Fear leads to anger... Anger leads to stress... Stress leads to doobies... and doobies lead to twinkies.

Doritos, my man, Doritos. Remember: Crunch all you want, they'll make more.

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(Damn, the Yoda-speak problem, I have still got, hmmm?)

This is serious, by the way. JA's been talking like this to everyone in the office.

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Now if I could just convince her to listen to some Miles Davis or John Coltrane. Oh well, I can always hope.

I think that Miles and Coltrane might be a bit tough as a starting point. Start her off with Ike Quebec's 'Heavy Soul'. Then, something like Sonny Clark's "Cool Struttin'". If that does not convince her to look at Jazz, nothing will. Start off on the blusey side.

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(Damn, the Yoda-speak problem, I have still got, hmmm?)

This is serious, by the way. JA's been talking like this to everyone in the office.

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Now if I could just convince her to listen to some Miles Davis or John Coltrane. Oh well, I can always hope.

I think that Miles and Coltrane might be a bit tough as a starting point. Start her off with Ike Quebec's 'Heavy Soul'. Then, something like Sonny Clark's "Cool Struttin'". If that does not convince her to look at Jazz, nothing will. Start off on the blusey side.

Oh, she's heard plenty of jazz, all kinds of jazz, since she was in the womb. I had this video from when she was still a baby and you could clearly hear Benny Carter's "Further Definitions" in the background. She's also sat with me and listened to some Ken Vandermark and enjoyed it! Now what I need is for her to put on some jazz to listen to on her own.

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(Damn, the Yoda-speak problem, I have still got, hmmm?)

This is serious, by the way. JA's been talking like this to everyone in the office.

Awesome, LOL! Syntactical inversions, I have caused.

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Awesome, LOL! Syntactical inversions, I have caused.

Lightened up the thread it certainly has!

PS I believe 'anastrophe' the correct term is.

Talking in Pig Latin we are.

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PS I believe 'anastrophe' the correct term is.

Great link.

To me, by far the most significant benefit of the Transporter/Squeezebox system is the concept of the "whole house music server". OK, I've got the high end system in a dedicated room, but much more of my listening is casual - while cooking, surfing the net, taking a bath, etc, and the whole house audio system has revolutionized music for me.
When I first became aware of music servers, I could see some appeal, but I would never had made the jump from CD to server just for my critical listening room. It has been a hell of a lot of effort and expense to get my server-based system going (I am not too good with computers so I needed quite a bit of help and ripping all these CD's has been a full-time job!).
But now I have my entire collection available in any room in my house - the Transporter in my high end system and the SB in the kitchen and I will get a few more SB's for the rest of the house.
And THAT access is the key to the success of the Slim system. Perhaps the Linn server could sound a little better, but I would bet not by much, but the Transporter/SB combo are the better mousetrap.