# iTunes Import Quality...



## macguy.nielsen (Sep 18, 2004)

I'm sure this has been done before, but here is a new one. It's just out of curiousity as to how many people actually convert to Lossless, or don't care and compress to 192 or lower.


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## ArtistSeries (Nov 8, 2004)

How about "I don't convert, I want the best sound possible?"


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## macguy.nielsen (Sep 18, 2004)

ArtistSeries said:


> How about "I don't convert, I want the best sound possible?"


That's called Apples Lossless.


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## KardnalForgotHisPassword (Oct 14, 2004)

AAC or MP3? I just started importing at 256 ACC, which I'm told is much improved over 256 MP3...

I'd never really noticed the difference between CD's and 192 MP3's until I got a great pair of <a href="http://www.etymotic.com/ephp/er6i.aspx">ear buds</a> over Christmas. Now I can't stand to listen most of my library, which was imported at a 'lower' (ie 192kps Mp3) bitrate...


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## ArtistSeries (Nov 8, 2004)

macguy.nielsen said:


> That's called Apples Lossless.


No, it's called .aiff


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## applebook (Aug 4, 2004)

ArtistSeries said:


> No, it's called .aiff


Wrong, lossless is lossless. The compression doesn't eliminate bits of sound, and there is NO SQ difference between PCM and lossless, not even with high-end gear like a Mark Levinson DAC and $10,000+ speakers or a nice headphone rig.


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## Moscool (Jun 8, 2003)

*I wish you were right...*

... but you're not:

I have started to compress all my CD library using Apple Lossless + Airport plugged into my Quad rig. The ESL63s are particularly good at pointing out small differences in 'natural acoustics' (e.g. voice, strings...). On some tracks lossless is hard to distinguish from the original, but in most there is a loss of spaciousness or depth and the sound comes across as slightly muted. 

Granted lossless is infinitely superior to iTMS junk but it is not really as good as the original. I know that in theory it should be, but practice is different. We have known for 20 years now that CD players are not created equal, although by now they should all more or less be...  

I suggest you try out a few 'vertical tastings': pick one of your favourite songs at encode it at all possible levels. You may find like me that the biggest sound difference starts at 160k (not even 192), so this is what I use for my iPod (I run two separate libraries).


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## gordguide (Jan 13, 2001)

Moscool, are you sure it's a difference between AIFF and Apple Lossless <i>format</i> and not processing (decompression on the fly) or some other non-identical issue that comes up when you must decompress on the fly that you're hearing?

If you're up to it, I suggest a little experiment: find a suitably difficult disk, and import it as both AIFF and ALF into iTunes and create a playlist of the disk in each format. Then burn each playlist to CD and compare the disks while playing back on your best CD player (ie a standalone unit rather than your Mac, if you have one).


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## ArtistSeries (Nov 8, 2004)

gord, I can confirm the jist of Moscool's observations. 
There seems to be a difference with complex harmonics, some voices recorded in natural settings and a few well recorded albums. 
Lossless is good but not great. Most will not notice. I know there is not supposed to be a difference. The test I ran, I made sure I burnt the CD at the slowest speed with gold CDs.


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## Pelao (Oct 2, 2003)

AAC at 160 for my iPod, as a reasonable balance between quality and size.


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## BobbyFett (Jan 12, 2005)

Moscool is completely correct. Just the same as a cdr copy of a cd burned in your cd drive is not as good as the original. 

They should be equal, but they're a long way from ever being so.

For the record, I import at 256AAC with VBR selected.


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## skippy1416 (Jun 26, 2005)

Since this thread has attracted the audiophiles on the board I was wondering if you could make some recommendations.

I have a eMac connected to a good but not great stereo (Harmon Kardon (back when that meant something) integrated amp, Paradigm bookshelf speakers) through an Edirol/Roland UA-1X USB to RCA connection. I imported my CDs to my Mac using 192 kbps.

I have been very busy (I have an 18 month old son) and have not really had a chance to listen very much. My question is: For a setup such as mine what quality setting would you recommend? The stereo is in a smallish room (10 X 12 den) with hardwood and a lot of hard surfaces. I only have a 40GB HD but I am willing to consider adding an external HD.


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## stand_1998 (Aug 13, 2003)

I'm not an audiophile, and my gear supports this statement.

But I do enjoy music and have imported all of my CD content using 128AAC. I cannot tell the difference between higher bitrates, so why use them?


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## Moscool (Jun 8, 2003)

stand_1998 said:


> I'm not an audiophile, and my gear supports this statement.
> 
> But I do enjoy music and have imported all of my CD content using 128AAC. I cannot tell the difference between higher bitrates, so why use them?


Hmm have you really done the comparison? Here is how to run the test:

1) Import at CD track using no compression at all (iTunes prefs/advanced/import/AIFF encoder)

2) Then use the advanced/convert this song menu after changing the prefs encoder to AAC 128, then 256

Each of these should have a significantly different sound.

In terms of 'is my hifi worth it', I suggest you plug good quality headphones in and check the difference. Like Pealo for me the size/quality balance is at 160 AAC.


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## stand_1998 (Aug 13, 2003)

Moscool, thank you for the tips... I'll try them out on the weekend.

If "highest quality sound" is something to achieve, then why not use a different program that supports advanced error checking. This is to make sure that the audio is 100% accurate in its digital form. Then you can convert to desired bitrate.

I did some testing with a program that ripped WAV files and generated an accuracy report. I was surprised how inaccurate some rips were. Of course I forget the name of the software, but remember an icon for Greyskull (He-Man)!

I'll do more investigating/testing over the weekend.


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## macsackbut (Dec 15, 2004)

192. I find it a nice balance between file size and quality.


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## okcomputer (Jul 18, 2005)

Pelao said:


> AAC at 160 for my iPod, as a reasonable balance between quality and size.


This is what I use as well. Better than 128, smaller file size than 192. I find that 160AAC compares to 192MP3.

=)


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## Bosco (Apr 29, 2004)

BobbyFett said:


> Moscool is completely correct. Just the same as a cdr copy of a cd burned in your cd drive is not as good as the original.
> 
> They should be equal, but they're a long way from ever being so.
> 
> For the record, I import at 256AAC with VBR selected.



What's the difference? Why aren't they the same. You're copying 1's and 0's not actual analog audio. 

For the record I prefer 192k as a compromise between size and quality.


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## HowEver (Jan 11, 2005)

.


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## ArtistSeries (Nov 8, 2004)

Bosco said:


> What's the difference? Why aren't they the same. You're copying 1's and 0's not actual analog audio.


That's what used to be said about CD and digital audio in general...


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## Bosco (Apr 29, 2004)

ArtistSeries said:


> That's what used to be said about CD and digital audio in general...



I was referring to digital vs analog copies. Digital copies are identical unless there's an error. In which case you'll know it without having to A/B it to the original.

Bouncing analog tape recordings is where you'll hear the difference. There's always some loss there.


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## BobbyFett (Jan 12, 2005)

Bosco said:


> What's the difference? Why aren't they the same. You're copying 1's and 0's not actual analog audio.


Yes, but are you reproducing the same 1's and 0's that are on the original? Hardly ever. There are many factors that cause you to produce an inferior copy; jitter, quirky timing in your computer's clock (not the one that tells the time) to name but a couple... 

Have a read here:

http://www.johnvestman.com/digital_myth.htm


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## Bosco (Apr 29, 2004)

BobbyFett said:


> Yes, but are you reproducing the same 1's and 0's that are on the original? Hardly ever. There are many factors that cause you to produce an inferior copy; jitter, quirky timing in your computer's clock (not the one that tells the time) to name but a couple...
> 
> Have a read here:
> 
> http://www.johnvestman.com/digital_myth.htm


Are we talking about the same thing here? I thought you were talking about making a CD to CD copy. Your link refers to making digital masters.

That's a whole new can of worms.


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## BobbyFett (Jan 12, 2005)

Bosco said:


> Are we talking about the same thing here? I thought you were talking about making a CD to CD copy. Your link refers to making digital masters.
> 
> That's a whole new can of worms.



sorry. wrong link.

http://www.stevehoffman.tv/forums/printthread.php?t=27313&pp=60
http://www.mrichter.com/cdr/primer/losses.htm


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## Bosco (Apr 29, 2004)

BobbyFett said:


> sorry. wrong link.
> 
> http://www.stevehoffman.tv/forums/printthread.php?t=27313&pp=60
> http://www.mrichter.com/cdr/primer/losses.htm



Are we in the audiophile realm here? If so I really don't want to get into a discussion on that. If we are, here's a link you may find interesting.


http://www.ilikejam.dsl.pipex.com/audiophile.htm


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## DBerG (May 24, 2005)

No compression at all, I hate to lose quality. I need all those precious bits!


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## okcomputer (Jul 18, 2005)

HowEver said:


> Although not as often as before, once in a while I still have to put a vinyl record on the Dual turntable and play it through my Pioneer system. I guess I can forget about there being a category for this method.


Mmmmm yes.

Radiohead and the Beatles never sounded so good. Vinyl = warm loveliness.


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## TimStalin (May 22, 2005)

@ stand_1998

I never really used to be able to here the problems with [email protected] until I started to listen to more jazz, then the problems became abundantly clear.

Now everything I encode is VBR 256. It seems to keep the audio clear enough for my not particularly picky ears. Also, if I only ever listen to digitally compressed music I won't know what I'm missing and will never pine for a more "pure" sound.


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## jdurston (Jan 28, 2005)

192 AAC with VBR
Don't have hard drive space for anything higher.


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## Moscool (Jun 8, 2003)

*The best kept secret in audio*



DBerG said:


> No compression at all, I hate to lose quality. I need all those precious bits!


There actually IS a format that is near perfect, and that is SACD: you get both the dynamic range of CD and the warmth of vinyl. I suppose that's what master tapes are supposed to sound like... I have a whole bunch of Rolling Stones dual layers and they make even their typical early 70s two-track trash recordings sound interesting...

When loitering on Amazon I always check for dual layer CDs: there is almost no price premium...


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## ramsesm (Jan 29, 2005)

Well, I'm not an audiophile but I can hear differences in quality depending on the ratebit on certain beats. I don't use the iTune build in importer as for some reason I don't like the results. (I had to re-do all of my library the first time I did it because of this). In fact, try listensing to a song from the same album iTunes sells vs the one you encode. I have found that its very different and Apple has got to be using a sound eng and another technique to encode the commercial ACCs. 

I'm for one using LAME (with an apple script in iTunes) and I select the bitrate based on the type of music I'm riping. Low bitrate on not so complex music (like a slow clasical ballad ) and higher bitrate for things like complex Flamenco, several clasical guitar or Rock where there are sounds in between the 128 bits you are not capturing (and not hearing). My typical setting is 192 but I have ecoded as low as 128 and as high as 320. So its all over the map for me depending on the song. LAME is very good and the quality produced is great.


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## gmark2000 (Jun 4, 2003)

jdurston said:


> 192 AAC with VBR
> Don't have hard drive space for anything higher.


Ditto. I have 60 Gigs ripped so far.


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## Moscool (Jun 8, 2003)

Bought a dedicated Mini HD (LaCie 250). So far about 100Gigs on it (rock only). Jazz is next, Classical will remain on CD (not really interested in creating playlists or shuffle in classical). My hunch is that 200G should be enough.


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## Howard2k (Feb 9, 2005)

A mix between 160Kb/s AAC and 192Kb/s AAC w/ VBR. 

If I like the track more I'll pump the bitrate to 192Kb/s AAC VBR. If it's a more average track I might just rip it at 160Kb/s AAC. Typically though it's 192Kb/s AAC VBR that I use now. 

I downloaded some ABX software for my PC and over my PC speakers I could not differentiate between 128Kb/s AAC and 160Kb/s AAC. I thought that I probably would have been able to but in a blind test I couldn't. Perhaps I'll repeat the test with the Shure E2cs and see if that makes the difference more noticeable.


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## applebook (Aug 4, 2004)

The idea that jitter somehow disrupts bits when they're being copied directly from a digital source (CD to CD) is hilarious. Jitter causes noise and distortion on DA to analogue, i.e. CD/ digital to SOUND, not lost bits on exact digital to digital. 

I suppose that when I make copies of pictures and word files, I've now created inferior secondary copies? No. The exact digits are retained, just like in digital audio. 

To sum it up, a digital to digital copy is an EXACT duplicate.


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## TimStalin (May 22, 2005)

Wouldn't a CHECKSUM of a lossless conversion to another format and then back to the original format either confirm or deny whether any bits were lost? Isn't lossless compression exactly the same as any other compression format, only using an algorithm which allows playback and is specifically tailored to audio data streams?

Edit: Of course I am only speaking of purely digital audio data.


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## gordguide (Jan 13, 2001)

" ... Moscool is completely correct. Just the same as a cdr copy of a cd burned in your cd drive is not as good as the original. ..."

Actually, CD-Rs often sound better than the original CD when used with a quality CD player, and not only because players that can read CD-Rs tend to have fewer interpretation errors and less jitter than those that can only read commercial CDs (they have different laser systems, and CD-R capable ones tolerate more variance in the quality of the optical meda).

"Jitter" is time-based distortion; all digital playback introduces some jitter and this form of distortion is unique to digital audio systems (analog disks or tape have zero jitter).

[One of the best features of the iPod is it's hard-disk based storage and the quality of it's playback electronics results in significantly less jitter than the majority of optical disk players you can buy are capable of.]

Since all sound is amplitude (volume) of frequencies over time, all three are critical aspects of reproduction, and any error in any one area introduces playback distortion (and tends to alter the other two as well).

Because CD-R and CD differ rather significantly in construction and therefore in the level of errors they generate when reading or interpreting data, they will introduce different levels of jitter and therefore must sound different and as it turns out, the flat, dye-based CD-R is easier to read accurately than the mechanically produced CD which requires the laser to focus on a landscape of mechanically stamped hills and dales.

Theoretically a CD has two levels of physical height and specific lengths that are multiples of an exact length; in reality they vary widely in depth and are not particularly exact in length; the player must decide, very quickly, whether they are supposed to be 1's or 0's, and live with the decision because it must do it again immediately. It's not the same as reading data (like a TIFF image); there is plenty of time to re-read or slow down to get it right if it's not music played back in real time.

Although many might imagine the different heights as discreet, as if they were made of Lego 1 block high and 10 blocks high, in reality they are quite close to each other. Perhaps one might think of flying over your neighborhood, where 1-story homes represent one value and 2 story homes the other. That is much closer to the microscopic reality. Pick a transition height (lets say 7 meters) and put them all in one category or another. A high single story home, or homes very close to 7m in height, will be incorrectly interpreted as the opposite of the data they are supposed to represent.

Although it's true that, in theory it's all 1's and 0's, the truth is (and checksums reveal) there is very little likelihood you can make a perfect bit-for-bit copy of a CD, no matter how hard you try or what means you use. And, it's probably not a good idea to do it in the first place, even if you can, since you would reproduce errors as faithfully as correct data. And every commercial CD has errors; a batch of commercial disks are not automatically identical to each other.

Luckily, they don't have to be perfect for music to come out the other end. It's a testament to the creativity of Sony and Phillips that they made a very robust specification that is extremely tolerant of error; much more so than any data disk is.

Turning on error correction, which is part of the Redbook Specification for playback, practically guarantees the copy will not be identical to the original; error correction reduces errors and should insure most errors on the CD are absent in your copy; in other words deliberately not bit-for-bit. All CD Players (walkmans, blasters, home stereo gear) have Error Correction on at all times; but computer CD-ROM drives do not normally incorporate it, and of course no Mac Optical drive does since Macs don't use the analog outs like some older PCs do for CD audio playback.

However, error correction does insure more accurate renditions of what was on the master; it's designed to reduce or eliminate the errors that are introduced when record companies make CDs (with a mechanical stamper on aluminum foil) or when we damage them in handling.

Nor is it necessary to have perfect copies to create music from a disk; the CD Specification insures it is remarkably indifferent to errors and has redundant methods that allow the playback system to find the data (it's written to multiple areas of every Redbook compliant CD multiple times), ignore non-critcal errors, or substitute "filler" data so that they are less obvious to us when listening. Simply taking advantage of the multiple areas where the data can be read is enough to recommend it; your "copy" may have more accurate data than the CD does when it has errors in the primary area the data is written to disk (and a scratch on the disk is going to inevitably create such errors).

Audio disk players encounter 3 kinds of error severity; with error correction enabled, as strange as it may seem, the first two kinds of errors can be corrected with 100% accuracy (and insuring your copy is "better" than the disk you read from, since hopefully your CD-R will not introduce more errors than the original disk had). Perhaps more importantly, since we're not (or shouldn't be) playing the disk when we rip them, the computer is free to take as long as it wants to get it right, and that should result in a copy that, when played back, introduces less jitter as well.

The level 3 errors cannot be corrected at all and will result in audible distortion of some kind on playback or in the ripped audio file. 

" ... If "highest quality sound" is something to achieve, then why not use a different program that supports advanced error checking. ..."

Redbook Error Correction can be turned on in iTunes at:
iTunes: Preferences: Advanced: Importing: Use Error Correction when reading Audio CDs
... then insure the box is checked.


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## applebook (Aug 4, 2004)

TimStalin said:


> Wouldn't a CHECKSUM of a lossless conversion to another format and then back to the original format either confirm or deny whether any bits were lost? Isn't lossless compression exactly the same as any other compression format, only using an algorithm which allows playback and is specifically tailored to audio data streams?
> 
> Edit: Of course I am only speaking of purely digital audio data.


True. The same goes for other lossless formats like FLAC, which is very popular for storage.


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## gordguide (Jan 13, 2001)

When an AIFF file is converted to Apple Lossless and stored on the HD, then that ALF file converted back to AIFF, checksum reveals it to be a bit-for-bit copy of the original. FLAC and Shorten are equally accurate.


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