A discussion of ripping and encoding/decoding software

[Steve A.]

Boy, I have sure learned a lot the past few months and still am a n00bie! I used to rip my CD's using EZ CD Creator, figuring that digital bits are digital bits... Not so!

It seems that at this point, a freeware program called EAC [Exact Audio Copy] has become the standard for ripping CD's, with more options than you can shake a stick at. I guess one goal is to transfer the files across the internet and then be able to create an exact copy of the original from the files (with the exact same gaps between the songs).

Stuff I've learned:

#1. SBE... "Silent But Ed-ly"? No, silly goose, "Sector Boundary Error". If you create your own WAV files and burn them to CD, you may have SBE problems which can add small gaps to the end of each track- mainly noticeable if the tracks are continuous, like a live show which is broken up into tracks. If each track is seperate and distinct then the added gap will probably not be noticeable.

More info on this- when burning an audio CD, the CD drive writes the data in full sectors, so if the file does not end on a sector boundary, the track will be padded with blank bits to fill out the final sector.

One handy tool to check and correct SBE problems is the freeware program "Trader's Little Helper". It offers two different options: fix mode and pad mode. In fix mode you input 2 or more files and it will move bits from one file to another, either forward or backward, so that all tracks will start on a sector boundary (the last track will be "padded" with extra blank bits). The other choice is the "pad" mode, which will look at each file individually and add blank bits at the beginning or end of each track so that there are no SBEs.

#2. FLAC is a handy format- [Free Lossless Audio Compression] Unlike most MP3 formats, there is no loss of information when the file is reduced to 40-60% of the original size of the WAV file. An added bonus is that you can add tags to your FLAC files, which will be displayed when you play them in WinAmp (or whatever). You can also add "replay gain" tags to the files, which will allow WinAmp to play all of the files at the same relative volume.

You can download FLAC plug-ins for programs like WinAmp and Cool Edit Pro so that the programs will recognize the FLAC format.

#3. You can configure EAC so that your CDs are ripped to FLAC files whenever you hit <Shift> F6. (If you hit <F6> by itself they are ripped to WAV files.) One problem I noticed- a few of my rips resulted in FLAC files with SBE flaws (supposedly not possible but it happened to me anyway). So I added "--sector-align" to the compression options for EAC, which seemed to work okay. HOWEVER... I found problems doing that with a live album- it would pad the end of each track so that there was a small gap between each track. :( For that album I ended up ripping to WAV and then using TLH to use "fix" mode for SBEs, since the EAC/FLAC automatic combination evidently uses the "pad" mode.

... Well, that's enough for now- any posts on this subject would be appreciated since I am still trying to get all of this figured out and configured. (I just learned how to get EAC to run in "Secure Mode" last night- hooray!)

Steve Ahola

[Steve Conner]

I always used a program called RipTrax with good results. It doesn't seem to be supported any more though. I guess I'll be changing to EAC soon...

[Steve A.]

I always used a program called RipTrax with good results. It doesn't seem to be supported any more though. I guess I'll be changing to EAC soon...

I never noticed any problems ripping with EZ CD Creator, but some of the private BT trackers are VERY picky about their uploads- one big plus with the earlier versions of EZ CD was that they would read the unfinalized Music CDR's I would burn with my CD recorder (I could burn a few songs, rip them and then go back later to add more songs to the CDR before finalizing it, which would save me money for the music CDR blanks which can be a LOT more expensive than data CDR's).

Supposedly dBpowerAMP is almost as good as EAC, and I think that they will be adding features to it to make it even better. Or so I heard. Their audio conversion features aren't recommended [for high end trade sites] because they don't check for errors as thoroughly as programs like Trader's Little Helper. [We are talking about the initial preparations for a high quality upload here- if you are just converting the files for your own use and you still have the original cds, dBpower is very handy to use.]

Steve Ahola

[Luijo]

I use the dB programs for format/bitrate conversion and so far have gotten great results. It is fast and doesn't slow down the PC too much.
You can convert between formats with no problem as long as you have all the needed codecs installed.
Their ripping program (cd input) works fine and is a lot faster than WMP. Sound quality is quite good, considering you are converting to a smaller size/quality file anyway.

[Sock Puppet]

I used Musicmatch Jukebox to rip my CD collection to mp3pro format. It's easy to use and does a good job of track name lookup and organising the music collection.

I remember that Album cover art downloader was useful at the time too.

Of course I have little interest in duplicating the gap between tracks:)

S.

[bob p]

FLAC is a good format -- much better than a lossy format such as MP3. In spite of the advantages that come with the lossless encoding formats, MP3 still has a lot of traction, presumably becuase it "got there first", because it has commercial backing, and because its what every n00b is told to use and most people don't know any better.

In addition to being an inferior format from a sound quality perspective, its proprietary. Every time that someone in the US buys an MP3 player, they're paying a royalty to Thompson Consumer Electronics (RCA) for licensing of the MP3 codec -- just like you pay for Apple's ALAC lossless codec when you buy an iPod or download from iTunes.

The end result? A "standards" war and hardware-software incompatability. In some respects, because of competing proprietary formats its like VHS and Beta all over again. I've decided to sidestep the issue by using open source encoding methods such as FLAC and Ogg Vorbis.

Back to the topic of CD burning -- Easy CD has been notoriously bad at the task of creating faithful transcriptions, especially with media like Playstation Games. These problems are intentionally built into the software. I quit using it a couple ofyears ago for precisely the reasons Steve mentiond. I've found that CD burning is much better on the Linux platform. I've been doing all of my ripping and writing on Linux for a couple of years now, and I've never looked back. As an added benefit, I haven't had to pay for any software or any software upgrades in a couple of years now, as all of the software is licensed under the GPL.

[Steve A.]

I use the dB programs for format/bitrate conversion and so far have gotten great results. It is fast and doesn't slow down the PC too much.
You can convert between formats with no problem as long as you have all the needed codecs installed.
Their ripping program (cd input) works fine and is a lot faster than WMP. Sound quality is quite good, considering you are converting to a smaller size/quality file anyway.

I think that dBpowerAMP was one of the earliest all-purpose conversion utilities and I've used it extensively. I do have a gripe with the MP3 support expiring unless you pay for the Power Pak- I don't see why it won't use the LAME codec already installed on your computer. :eek:

But these high-end trader sites are pretty picky (hey- they won't even accept my rips! :D )

Steve Ahola

EDIT: I had installed mkw Audio Compression Tool 0.97 BETA quite some time ago, but never did use it much at all. I've been using it to create MP3 files from WAV files, without having to pay a license fee. But to first convert my FLAC files to WAV files, the easiest tool is dBpowerAMP...

[Steve A.]

I used Musicmatch Jukebox to rip my CD collection to mp3pro format. It's easy to use and does a good job of track name lookup and organising the music collection.

I remember that Album cover art downloader was useful at the time too.

Of course I have little interest in duplicating the gap between tracks:)

S.

I had a trial version of MM that came with my first MP3 player and it would rip 25 songs for free, and then nag you for payment for a license. To shut it up, I had to uninstall it. Years later when I finally installed a firewall I learned that MM was still trying to dial out and connect with its masters from an alien planet, I think.

"No interest in duplicating the gap between tracks"? Heck, that is part of the experience of listening to a well-made album... LOL With some trashy collections ("as seen on TV"), they use a fixed 1 or 2 second gap between each song, but for the classic albums the gap is usually different on each song, depending on the song before it. (I think that the best way to handle the gap is to simply add it to the end of the previous track- but then if you try to resequence the album that could create problems. Can't win for losing...)

With EAC and AccurateRip, you can have it automatically access the freeDB database, which is information supplied by users such as yourself so be sure to chek thee spellink! :eek:

[Steve A.]

FLAC is a good format -- much better than a lossy format such as MP3. In spite of the advantages that come with the lossless encoding formats, MP3 still has a lot of traction, presumably becuase it "got there first", because it has commercial backing, and because its what every n00b is told to use and most people don't know any better...

Well, FLAC will shrink files to 40-60% of their original size, while with MP3 you can get down to 10-20% and still have them sound pretty good. At one of the private trackers they accept MP3's at 192kbps or higher along with FLAC files, and there is a constant conflict between the two factions, with each one requesting uploads in their own format.

If I was just listening to music I doubt if I could tell the difference between a 320kbps MP3 file and the original WAV file (or a ripped and encoded FLAC file). However, I like to edit song files in Cool Edit Pro and going from lossy to lossless and back to lossy can get messy. :eek:

My other gripe with MP3's is that there is ALWAYS a small gap at the end of the file so if you convert a live show into individual MP3 files, there will be a click or pop at the end of each track. (It was driving me crazy because I was manually removing the gaps and then saving the files and reburning them, only to find the gaps still there! It was almost like when I tried to edit out the artifacts on a low-res JPG file- they kept coming back! :confused: )

There is a workaround to that problem- you have a single MP3 file for the entire concert but supply a CUE file which will tell a burning program where to add song breaks on your CD. But I generally avoid MP3 files if I can... except for loading up my iPod! :cool: (If you have the files in FLAC you can always convert them to MP3 files of any resolution, but if you start out with MP3 you can NEVER make them lossless...)

Steve

[bob p]

Well, FLAC will shrink files to 40-60% of their original size, while with MP3 you can get down to 10-20% and still have them sound pretty good. At one of the private trackers they accept MP3's at 192kbps or higher along with FLAC files, and there is a constant conflict between the two factions, with each one requesting uploads in their own format.

the best option is probably to use FLAC as an archive medium, and then re-rip/convert to other formats as needed when you need to reformat the data for a particular device that is limited by what formats it can handle.

even though i try to stay on the forefront of this stuff in the open source world, in some respects i often feel that we're wasting our time comparing this that and the other thing when it comes to digital audio. digital audio in the way that the wind seems to be blowing is the antithesis of "High Fidelity" in the way that we used to think of it. i know that i'm showing my age in saying this: digital audio has totally changed the listening experience. listening to music used to be an event in which your attention was totally focused on a high fidelity sonic experience. with the advent of the iPod, the listening experience has evolved into background Muzak as the soundtrack for our lives. i guess its inevitable that as it becomes easier to play music and to take it with you, the quality of service becomes less important. in sime respects, iPods and the like are today's take-it-with-you transistor radios, not HiFi devices.

look at consumer electronics. digital audio has reduced HiFi hardware from a stack of McIntosh integrated components (or Krell, or Mark Levinson or whatever) to a microchip on an iPod nano. The sotware library is no longer high quality vinyl, open reel tapes running at 15 ips or a critically mastered CD -- now its an .MP3 on a stick. the focus is no longer on getting the highest fidelity sound reproduction we can afford -- now the music is molested and maximally compressed, purposefully compromising fidelity because the important consideration is making one more data file fit on a digital memory card. for the music that's really pretty sad.

in our quest for tone, we spend countless amounts of time and money building, experimenting and refining our tube amps in order to capture those elusive incremental gains in tonality. in the end all of our effort is doomed to be lost, because if we want a large number of people to hear it, the track is going to be manipulated and compressed into the smallest possible .MP3 file to make it fit on somebody's iPod. sigh.

i've got a large collection of digital audio files that i've accumulated from various sources (and the collection continues to grow), but i don't really consider most of it to be high fidelity, or even remotely suitable for critical listening. its good for background music while i work on the PC and not much else. even though i have a totally wired house, i still haven't bothered to feed the output from my PC soundcard into my "real" listening stereo.

have you integrated PC-based digital audio into your "main" audio systems? like most people, i find the fidelity of digital audio and the iPod to be acceptable for what it is (the replacement for the Sony Walkman), but i don't think its on par with my audiophile system. in some respects, i think that with the advent of the iPod we may be hearing the death-knell for high fidelity audiophilism. sorry to hijack your thread, Steve.

[Steve Conner]

My feelings on EZ CD Creator are more or less summed up by the projectile vomiting scene in The Exorcist. It's not so much the program itself (though it's nothing spectacular) as the crap that comes bundled with it and installs by default. Anyway, anything with "EZ" in the title makes me want to run over Bill Gates' nut sack on a skinny tyred racing bike.

I totally agree with Bob P's thoughts on audio compression, but as a part-time musician and wannabee recording engineer, it puts me in a dilemma. I need to stay true to my beliefs on not using too much compression (of both the dynamic kind and the bitrate kind) while still creating tracks that will appeal to the iPod-on-the-subway sector. Sometimes I think that enjoying music and enjoying accurate sound reproduction are two totally separate things, and that a good tune should be enjoyable whether it's coming off an analog master tape or a cheap MP3 stick, and that we worry too much about whether Mullard EL34s sound better than Sovteks or whatever.

Personally, I have an iPod (it's actually a Korean iRiver clone with better recording facilities than a real iPod, great for bootlegging and recording ideas and practice sessions) but I also have a big collection of old-fashioned CDs that I play in a proper CD player (one that can't play CDs of MP3s and actually gets the gaps between tracks right!) through a homebrew amp and a huge pair of audiophool speakers. I ripped a lot of my CDs to listen to at work or on the move, but I always play the originals at home. I also have a pile of stuff that I ripped from vinyl to uncompressed WAV files. But then, I like to listen to streaming internet radio, and MP3s from unsigned artists that I could never hear uncompressed.

I have integrated PC audio into my hi-fi, in that my hi-fi, my PC and my recording gear are all tangled together in a huge mess of wires. MP3s and streaming radio end up getting played back through the same Delta 1010 24-bit audio card, amp and speakers that I use for recording, mixing, and listening to CDs.

Steve A: I could write a whole book on why and how the gaps between tracks get messed up by the ripping process, and whose nads need run over by what vehicles to improve matters. The facts to bear in mind are:

CD audio naturally comes in blocks of 2352 (iirc?) bytes, and ripping programs can't rip part blocks. This is mandated by the way the hardware in CD-ROM drives works. So if the gap between tracks is partway through a block, the average ripper program rips the whole block and pads the end of the previous track and the beginning of the next one with silence. I think some newer rippers may try to negate this.

CD burning software, when burning in track-at-once mode, does the same thing: pads the ends of your WAV or MP3 files with zeros to fill them out to a multiple of 2352 bytes. It always does this as a fundamental consequence of how track-at-once works. So, burn in disc-at-once mode whenever possible.

MP3 players treat each track as an individual entity and often introduce small pauses as they load the next track. CD players that are capable of playing MP3 CDs often suffer from the same problem. Old-fashioned CD players play the whole disc as a single stream of bits from beginning to end.

All of this adds up to be REALLY frustrating when you're ripping a collection of DJ mix CDs. :mad: The Rockbox firmware for portable MP3 players has a gapless mode where it tries to detect these spurious lumps of zeros and throw them away to get your DJ mixes sounding the way they were meant to. AFAIK. It's certainly got the smoothest track changeover I've ever seen.

The final insult was when we got together $500 to have our band recorded in a fancy studio with tube mics and vintage analog thingies, and our frontman then made preview copies of it to send out, on his PC with Windows Media Player, which ripped it, transcoded it to low bandwidth WMA, then transcoded that back to WAV for CD burning. Talk about crimes against high fidelity :(((

[David Schwab]

Boy, I have sure learned a lot the past few months and still am a n00bie! I used to rip my CD's using EZ CD Creator, figuring that digital bits are digital bits... Not so!

It seems that at this point, a freeware program called EAC [Exact Audio Copy] has become the standard for ripping CD's, with more options than you can shake a stick at. I guess one goal is to transfer the files across the internet and then be able to create an exact copy of the original from the files (with the exact same gaps between the songs).

I had a big discussion with someone about this a couple of years ago. All audio CD's have error correction built in (Cross-Interleaved Reed-Solomon Coding), because during the manufacturing process, there are going to be physical defects in the aluminum that holds the pits. You end up with a combination of random and burst errors.

Any time you play a CD, there is going to be some bits rounded off and so on, and you really can't hear the difference. A CD player uses error correction to play back the CD. A program like EAC claims to do an exact copy, but all it's doing it making an exact copy of a disk that already has errors! Only it's using the error correction algorithm that is built into every CD player. This is a tad redundant, since playing that exact copy of the "flawed" CD will be corrected at the CD player.

So first the CD player uses an interleaving scheme, and if that doesn't work it uses an interpolation scheme where it tries to "guess" the content of the sample by looking at the nearest neighbors. it wont "fix" the error, but it will make it inaudible by gracefully degrading the signal to mask the clicks and pops.

iTunes has an error correction setting, that uses the same principals as EAC to copy an audio CD.

So in my opinion, any quality CD duplicating program will make an exact copy of an audio CD... which is not to say the CD is not flawed in the first place. Things like EAC might help with damaged CD's, but I've never heard an improvement in sound quality.

I use Roxio Toast Titanium for duplicating CDs...

But give it a try and see. :)

[David Schwab]

CD audio naturally comes in blocks of 2352 (iirc?) bytes, and ripping programs can't rip part blocks. This is mandated by the way the hardware in CD-ROM drives works. So if the gap between tracks is partway through a block, the average ripper program rips the whole block and pads the end of the previous track and the beginning of the next one with silence. I think some newer rippers may try to negate this.

Yep, 2352... but that's for a data CD. And after error correction its 2048.

The smallest entity in the CD audio format is called a frame. A frame can accommodate six complete 16-bit stereo samples, i.e. 2×2×6 = 24 bytes. A frame comprises 33 bytes, of which 24 are audio bytes (six full stereo samples), eight CIRC-generated error correction bytes and one subcode byte. The eight bits of a subcode byte are available for control and display.

Under Eight-to-Fourteen Modulation (EFM) rules, each data/audio byte is translated into 14-bit EFM words, which alternate with 3-bit merging words. In total we have 33*(14+3) = 561 bits. A 27-bit unique synchronization word is added, so that the number of bits in a frame totals 588. The synchronization word cannot occur in the normal bit stream, and can thus be used to identify the beginning of a frame.

Data on a CD-ROM are organized in both frames and sectors, where a CD-ROM sector contains 98 frames, and holds 98×24 = 2352 (user) bytes, of which 304 bytes are normally used for sector IDs and an additional layer of error correction, leaving 2048 bytes for payload data.

Any program that extracts audio data from a CD (I refuse to say "rip" because that means Raster Image Processing... and I'm ripping files in this context all day.. but you don't rip audio files, only graphic files) will read it correctly, because that's how they are made to work.

One of the best ways to get an error free copy is to do it at 1X, the speed audio CDs were made to operate at.

[Steve A.]

... I totally agree with Bob P's thoughts on audio compression, but as a part-time musician and wannabee recording engineer, it puts me in a dilemma. I need to stay true to my beliefs on not using too much compression (of both the dynamic kind and the bitrate kind) while still creating tracks that will appeal to the iPod-on-the-subway sector. Sometimes I think that enjoying music and enjoying accurate sound reproduction are two totally separate things, and that a good tune should be enjoyable whether it's coming off an analog master tape or a cheap MP3 stick, and that we worry too much about whether Mullard EL34s sound better than Sovteks or whatever...

Steve A: I could write a whole book on why and how the gaps between tracks get messed up by the ripping process, and whose nads need run over by what vehicles to improve matters. The facts to bear in mind are:

CD audio naturally comes in blocks of 2352 (iirc?) bytes, and ripping programs can't rip part blocks. This is mandated by the way the hardware in CD-ROM drives works. So if the gap between tracks is partway through a block, the average ripper program rips the whole block and pads the end of the previous track and the beginning of the next one with silence. I think some newer rippers may try to negate this.

CD burning software, when burning in track-at-once mode, does the same thing: pads the ends of your WAV or MP3 files with zeros to fill them out to a multiple of 2352 bytes. It always does this as a fundamental consequence of how track-at-once works. So, burn in disc-at-once mode whenever possible...


Steve- I think Bob was referring to DATA compression rather than AUDIO compression- I remember your feelings about that! LOL

I edit song files visually as well as aurally- I like to see plenty of "hair" on the waveforms, rather than the solid block you get from over-compression. I like to bring the overall volume up a bit (so that you can play it right after the new RHCP album without having to turn the volume right... at least, too much!) In dealing with tracks that have already been mixed down to stereo, you can mess with the dynamics to bring out different instruments (I'll use Native Waves L-1 Ultramaximizer+ for that).

EAC (Exact Audio Copy) was written expressively to make accurate copies of CD's so it will read them and write them very accurately. There are many settings that can screw up a rip- like deleting the silence at the beginning and end of a track. Tack the gap onto the end of the previous track and you are good to go. :rolleyes:

I remember reading about sector alignment in Cool Edit Pro, but never bothered to follow their suggestions. You want the files you are writing to disk to be sector-aligned so that there are no gaps to be filled in when your disk is being burned. (That is mainly a problem with live recordings, with one track going right into the next track.)

If your recording is sector-aligned, then when you extract the audio later, there should be no gaps- at least if you are using a program like EAC. As for Track-At-Once (TAO) burns, they will put in a 2 second gap between tracks. (Back in the early days of CDR drives, some players would work better with disks burned Track At Once- I found that out myself the hard way! But modern players should have no problem with DAO burns.)

Steve Ahola

[Steve A.]

the best option is probably to use FLAC as an archive medium, and then re-rip/convert to other formats as needed when you need to reformat the data for a particular device that is limited by what formats it can handle.

even though i try to stay on the forefront of this stuff in the open source world, in some respects i often feel that we're wasting our time comparing this that and the other thing when it comes to digital audio. digital audio in the way that the wind seems to be blowing is the antithesis of "High Fidelity" in the way that we used to think of it. i know that i'm showing my age in saying this: digital audio has totally changed the listening experience. listening to music used to be an event in which your attention was totally focused on a high fidelity sonic experience. with the advent of the iPod, the listening experience has evolved into background Muzak as the soundtrack for our lives...

look at consumer electronics. digital audio has reduced HiFi hardware from a stack of McIntosh integrated components (or Krell, or Mark Levinson or whatever) to a microchip on an iPod nano. The sotware library is no longer high quality vinyl, open reel tapes running at 15 ips or a critically mastered CD -- now its an .MP3 on a stick. the focus is no longer on getting the highest fidelity sound reproduction we can afford...

i've got a large collection of digital audio files that i've accumulated from various sources (and the collection continues to grow), but i don't really consider most of it to be high fidelity, or even remotely suitable for critical listening. its good for background music while i work on the PC and not much else. even though i have a totally wired house, i still haven't bothered to feed the output from my PC soundcard into my "real" listening stereo.

have you integrated PC-based digital audio into your "main" audio systems? like most people, i find the fidelity of digital audio and the iPod to be acceptable for what it is (the replacement for the Sony Walkman), but i don't think its on par with my audiophile system. in some respects, i think that with the advent of the iPod we may be hearing the death-knell for high fidelity audiophilism. sorry to hijack your thread, Steve.

Bob:

As you suggest I use FLAC as the archiving format on my hard drives- I find it even better than the WAV files I used to save from my rips (and not just due to the smaller file sizes). You can add tags to FLAC files which are read by Nero when authoring a CD project. When playing the FLAC files in WinAmp the optional replay gain figures are recognized, so that each album will have roughly the same volume (while keeping the separate dynamics of each track). Plus Plus Plus all of the way across.

When you say "digital audio" I believe that you are referring to files that have been molested by lossy compression (namely MP3 files). I personally find unmolested digital audio files to have much more potential than my scratched up vinyl albums. While cds are 16 bit/44.1mHz, you could make digital audio files that are 24 bit and 96mHz for much higher resolution and bandwidth.

I've converted a lot of my scratched up albums into CDs, and the results have been really good- once I find and correct the flaws that can be corrected, I never have to worry about it getting more scratches (as I would with a vinyl album).

But there is a downside to the AD conversion process used in making CD's- as Speed Racer used to say, it can make the drummer's cymbals sound like a salt shaker... :eek:

I have to say that the more recent CD's usually have decent cymbal sounds- perhaps they sample the tracks at 24 or 32 bit for the initial conversion. Or maybe they just try to avoid the annoying frequencies when recording and mixing it down.

I think of MP3's as having the same fidelity as radio broadcasts and audio cassette recordings when I was growning up- certainly nothing near as good as a long play record. I don't understand the point of downloading an album in MP3 format, unless you just want to audition it in lo-fi to help you decide if you should get a *decent* copy of it later. LOL

Steve Ahola

[bob p]

When you say "digital audio" I believe that you are referring to files that have been molested by lossy compression (namely MP3 files). I personally find unmolested digital audio files to have much more potential than my scratched up vinyl albums. While cds are 16 bit/44.1mHz, you could make digital audio files that are 24 bit and 96mHz for much higher resolution and bandwidth.

I've converted a lot of my scratched up albums into CDs, and the results have been really good- once I find and correct the flaws that can be corrected, I never have to worry about it getting more scratches (as I would with a vinyl album).

But there is a downside to the AD conversion process used in making CD's- as Speed Racer used to say, it can make the drummer's cymbals sound like a salt shaker... :eek:

I have to say that the more recent CD's usually have decent cymbal sounds- perhaps they sample the tracks at 24 or 32 bit for the initial conversion. Or maybe they just try to avoid the annoying frequencies when recording and mixing it down.

I think of MP3's as having the same fidelity as radio broadcasts and audio cassette recordings when I was growning up- certainly nothing near as good as a long play record. I don't understand the point of downloading an album in MP3 format, unless you just want to audition it in lo-fi to help you decide if you should get a *decent* copy of it later. LOL

I have to admit, I'm still not enamored with any of the digitized recordings, for reasons like those that Speedy mentioned -- proper quantization of some signals just isn't as easy as most people think it is. The sounds of cymbals, glockenspiels, triangles, etc. can be particularly revealing tests for critical listening. As it turns out, when I had written earlier about the A/B tests between the $700 Denon and the $1000 Nakamichi CD players, I was listening to classical recordings that had triangles and glocks in them. In some respects, having a good ear can be a curse. HiFi audio is alot like wine. Once you can taste the difference between a $130 and a $150 bottle of wine, you're cursed for life! Especially when you have a beer budget!

I guess I would agree that the MP3 is the new "demo" format that many people will use to decide if they want to own the track on "hifi" media or not. The recording industry continues to see sales growing year over year, so I guess digital piracy isn't really hurting them. I guess Lars whats-his-name from Metallica successfully intimidated a lot of customers with those Napter lawsuits against the 12-year old kids.

Regarding radio, analog broadcast radio can be very HiFi, even though alot of the time it isn't -- the problem is that most stations just rolled off everything above 15K for whatever reason. As an aside, I've acquired an 1964 Scott 350-D Stereo Tuner (last of the all valve tuners from Scott), which was regarded as the premier tuner of the tube era. It needs tubes, but believe it or not, got it in a dumpster dive and saved it from going into the landfill. Now if I could find a free McIntosh or Dynaco power amp on its way to the landfill...

[David Schwab]

I have to admit, I'm still not enamored with any of the digitized recordings, for reasons like those that Speedy mentioned -- proper quantization of some signals just isn't as easy as most people think it is. The sounds of cymbals, glockenspiels, triangles, etc. can be particularly revealing tests for critical listening.

I think another issue is the brickwall filter used to prevent aliasing. There is information above our hearing that we use, such as phase relationships and stuff. We lose most of that with standard digital formats. The upper harmonics aren't accurate. The resolution is too low.

I think this DVD audio format should improve the situation greatly, since you will be able to use a higher sample rate and bit depth.

Still doesn't help with lossy compressed audio though.

[Steve Conner]

I don't get it. Surely you can either hear a frequency or not, and if you can't hear it, it doesn't matter if it's filtered out.

Of course, it is possible for filters to cause weird phase shifts and amplitude ripples in their passbands, so a filter that cuts at 20kHz could be messing with phase all through the teens of kHz. It's very difficult to design brickwall filters that let the whole audio band through, stop all aliasing from a 44.1kHz sample rate, and don't ripple either the amplitude or the phase of signals near the top of the passband: a tradeoff has to be made between all of these quantities, and the "sound" of the DAC depends on the particular balance the designer chose.

I think that is the sole reason for audible differences between DACs, and the presence of ultrasonic information is a red herring. It must be, or else everyone who ever measured the range of human hearing got it wrong.

Personally, I think I prefer the sound of DACs that use a less vicious filter to save mangling the HF phase and transient information, at the cost of either rolling off a little of the extreme high end, or allowing a bit of aliasing to bleed back into the passband. Some DIY DACs take this to an extreme and use no anti-alias filter whatsoever, either digital or analog.

[David Schwab]

I think the whole idea is we do not perceive frequencies above a certain point as "sound" but there is still information there that we process. Same can be true of very low frequencies.

Our brains process a whole lot of stuff that we are consciously unaware of.

Also a very severe brick wall filter has to be doing something to the phase alignment in the upper harmonics, and that can't be a good thing.

I'd imagine at some point that storage will be so cheap, and internet connections so fast, that we will be able to use uncompressed audio in our portable devises. Or at least non lossy compressed files.

[Steve A.]

I have to admit, I'm still not enamored with any of the digitized recordings, for reasons like those that Speedy mentioned -- proper quantization of some signals just isn't as easy as most people think it is. The sounds of cymbals, glockenspiels, triangles, etc. can be particularly revealing tests for critical listening...

Bob:

I guess you are looking at things as an audiophile while I look at them as a someone who has been making serious home recordings for 30 years (figure 40 years for some not-so-serious stuff). I would work hard mastering 2 or 3 tracks to a 7 1/2 ips reel-to-reel tape and then try to dub decent copies to audio cassette, hoping that they would play right on everybody's tape deck. 22 years I got my first 4 track home studio, which upped the ante a little bit, but was still stuck with using audio cassettes for distribution. So being able to edit digital files and burn them to a CD, or distribute them as FLAC files on the internet- that is so much better than things used to be!

I don't think I hear much over 10khz anyway, and if I get cymbals sounding like a salt shaker, I either take them out of the mix, or just EQ so that they sound like something altogether different... LOL

As for dubbing LP's to CD, it sure beats dubbing them to audio cassettes! I just did an album that I had picked up 30 years ago as a cut-out and it had hardly been played at all (Mel Brown's The Wizard on Impulse!) and it sounds great to me. I polished up the digital files and it sounds better than it ever did on a turntable (since I removed the few pops and clicks). As a matter of fact I just uploaded an MP3 of it as a sound sample:

Mel Brown - Ode To Billie Joe [Impulse! A-9169 - 1968]

http://www.megaupload.com/?d=0C71TNC4

Steve Ahola

[Steve A.]

I had a big discussion with someone about this a couple of years ago. All audio CD's have error correction built in (Cross-Interleaved Reed-Solomon Coding), because during the manufacturing process, there are going to be physical defects in the aluminum that holds the pits. You end up with a combination of random and burst errors.

Any time you play a CD, there is going to be some bits rounded off and so on, and you really can't hear the difference. A CD player uses error correction to play back the CD. A program like EAC claims to do an exact copy, but all it's doing it making an exact copy of a disk that already has errors! Only it's using the error correction algorithm that is built into every CD player. This is a tad redundant, since playing that exact copy of the "flawed" CD will be corrected at the CD player.

So first the CD player uses an interleaving scheme, and if that doesn't work it uses an interpolation scheme where it tries to "guess" the content of the sample by looking at the nearest neighbors. it wont "fix" the error, but it will make it inaudible by gracefully degrading the signal to mask the clicks and pops.

iTunes has an error correction setting, that uses the same principals as EAC to copy an audio CD.

So in my opinion, any quality CD duplicating program will make an exact copy of an audio CD... which is not to say the CD is not flawed in the first place. Things like EAC might help with damaged CD's, but I've never heard an improvement in sound quality...

One of the reasons why EAC is the recommended or required ripper at many sites is that is does generate rather detailed reports, noting your settings along with any errors in the process. EAC also supports AccurateRip, which compares the results of your rip with a rather large database, giving you a confidence rating (AccurateRip will also do an initial test of your drive to help you set the read offset value properly).

Error correction or not, sector alignment errors (aka "sector boundary errors") can produce noticeable pops between tracks which were not on the original CD. (This is only noticeable on albums in which the tracks run together, such as live albums or a very obscure album evidently for astonomy buffs called "Dark Side Of The Moon".)

You bring up a good point- it would be interesting to rip the same CD several times in EAC to see if the checksums are the same. And then try other programs to see how the checksums compare.

As you suggest, *EXACT* Audio Copy might be a bit of a misnomer, but it does seem to generate more consistent results than most of the other programs out there. (dbPowerAMP is supposed to be coming out with a new version with more bells and whistles than EAC.)

The other programs seem to work okay if you intention is to create a library of MP3 files, but if you will be burning them to CD I think that you will get better, more consistent results with EAC. Other than clicks from sector boundary errors, I'm not sure if any of us can really tell the difference in listening to a single audio file ripped from a CD using the different programa (I think that the read offset has to do with when the track starts and ends, and doesn't affect the actual audio data in the middle).

Some ripping programs automatically strip out the silence at the beginning and end of each track, which can affect the sequencing if you burn them to disc. In a well-produced album, the gaps between the songs are like white spaces in a painting. If you want to have the same experience as the original CD, the gaps should be the same, as well as the relative volume between the tracks (like if someone decides to "normalize" all of the tracks individually... a definite "no no"... LOL)

Steve Ahola