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iTunes encoding changed over the years/versions?

post #1 of 11
Thread Starter 

Hi all,

 

I was in the process of converting some of my old lossy AAC to ALAC and in quite a few tracks I noticed that I was very hard pressed trying to hear a difference between my old 160kbps AAC vs the newly recorded ALACs. This is listening through my Benchmark DAC1 Pre (USB, Audirvana+), Stax SRM-727A, and SR-009. As a backup, I also listened via the same DAC but Ortofon Hd-Q7 amp & Fostex TH-900...and asked my wife to have a listen too. Both of us listened hard and couldn't hear noticeable differences.

 

After converting a few different albums comparing, I did finally managed to pick up some that I could hear differences and a trend started to form. It seemed really old rips from iTunes 4.0.1 even at lossy 160kbps actually sounded very very good, but along the way somewhere around iTunes 6.0.3, it sounds like the algorithm had changed and actually got worse?

 

Although conceptually illogical, it makes me curious if so-called Apple Lossless over the years may have changed too 'cos after all, it's an algorithm.

 

Does anyone who have the same track rips :-

 

1) lossy from old iTunes & new iTunes confirm that they sound different?
2) lossless from old iTunes and new iTunes comment if they sound exactly the same?

 

Please note that I'm looking for genuine practical experiences rather than theoretical or conceptual opinions here (i.e. none of the "lossless is lossless" comments please).

 

TIA

post #2 of 11

You are "re-ripping" these tracks into your library via CD or some other source right? Not up-converting AAC to ALAC?

 

"Converting" a low bitrate track into a high bitrate track doesn't do anything for the sound quality. What ever the song was originally encoded at, is what it will stay at.

 

You mention converting and not re-ripping or re-encoding which is why I ask.

post #3 of 11
Quote:
Originally Posted by Redrider469 View Post

You are "re-ripping" these tracks into your library via CD or some other source right? Not up-converting AAC to ALAC?

"Converting" a low bitrate track into a high bitrate track doesn't do anything for the sound quality. What ever the song was originally encoded at, is what it will stay at.

You mention converting and not re-ripping or re-encoding which is why I ask.

What this person said. If you try to convert lower quality tracks to higher quality, nothing will happen and it may even degrade the sound. If you want to get true apple lossless you would have to re rip every CD into lossless. I learned this the hard way. When I converted my 320kbps to lossless there was no sonic difference, and an extremely prominent hiss appeared. I had to re rip all of my music to get rid of the hissing.
post #4 of 11
Thread Starter 

Sorry I should have been clearer and used my terms interchangeably. I do mean re-ripping. In this case using the very same CDs over the years but the hardware has obviously changed. Back in the "old" days I ripped the CDs with iTunes 4.0.1 on some PowerPC based Mac to AAC 160kbps, then over the years ripped CDs with iTunes 6.0.3 on early intel-based Macs to AAC 160kbps, and today iTunes 10.6.3 on Intel iMac to ALAC.

 

What I find is that the current ALAC rips are (almost?) indistinguishable from the old 160kbps AAC rips from iTunes 4.0.1 with relatively high end gear.

However the same ALAC rips are a noticeable improvement over 160kbps AAC rips from iTunes 6.0.3 with the same gear.

 

Which seems to imply, Apple's changed it's lossy ripping algorithm has gotten worse as iTunes upgrades?

post #5 of 11
Quote:
Originally Posted by AnakChan View Post

Sorry I should have been clearer and used my terms interchangeably. I do mean re-ripping. In this case using the very same CDs over the years but the hardware has obviously changed. Back in the "old" days I ripped the CDs with iTunes 4.0.1 on some PowerPC based Mac to AAC 160kbps, then over the years ripped CDs with iTunes 6.0.3 on early intel-based Macs to AAC 160kbps, and today iTunes 10.6.3 on Intel iMac to ALAC.

 

What I find is that the current ALAC rips are (almost?) indistinguishable from the old 160kbps AAC rips from iTunes 4.0.1 with relatively high end gear.

However the same ALAC rips are a noticeable improvement over 160kbps AAC rips from iTunes 6.0.3 with the same gear.

 

Which seems to imply, Apple's changed it's lossy ripping algorithm has gotten worse as iTunes upgrades?


It might be that the algorithms have changed or it could also be the physical disk drive that was used to rip the CD. Not all drives are made equally and some are more accurate and are of better quality than others so maybe that has a part to play.

 

Also keep in mind that depending on the song, you might not tell a lot of differences between formats. With a techno song that is mostly synthesized, you may not hear a difference because the techno song doesn't have the complex waveforms that an orchestral track would.

 

Foobar2000 has an extension that will break down and compare different encodings of songs into a binary form and spot out technical differences. Maybe give that a try and see if it explains anything.

post #6 of 11

What a marvelous topic. I've wondered about it all; and, although I have not noticed the effect shared by the OP, I have noted, among my rips, HDTracks, and iTunes downloads, when compared to CD, SACD, or Blu Ray from my fabulous home theatre system, that  some of my 128k iTunes downloads do not  seem to have the fidelity of CD. Today's 256k downloads sound to me to be identical to SACD. HDTracks sound identical to SACD. CD sounds identical to SACD.  So, not wanting any less convenience or expense than necessary, I buy CD's at my area's used book and music store and download mostly from iTunes. Today, storage is not an issue so I rip to ALAC. FLAC downloads are converted to ALAC using DB poweramp and are placed in my iTunes library. It's all real tidy.


Edited by sterling1 - 8/22/12 at 6:30am
post #7 of 11

So what about the today 2012 latest iTunes release ?

do they provide the choice now to buy the high quality or it is basically the limitations of AAC compressions itself ?

post #8 of 11

Music from the ITunes store is AAC. Recent stuff I've downloaded has all been 256k. My downloads from HDTracks, which are 24/96 flac files, are converted to ALAC with dbpoweramp so that those files can be stored in iTunes. My CD's are converted to ALAC, ripped with the iTunes media player.

post #9 of 11
Quote:
Originally Posted by sterling1 View Post

Music from the ITunes store is AAC. Recent stuff I've downloaded has all been 256k. My downloads from HDTracks, which are 24/96 flac files, are converted to ALAC with dbpoweramp so that those files can be stored in iTunes. My CD's are converted to ALAC, ripped with the iTunes media player.

Sterling1, many thanks for sharing the information here, so what should I do to make sure that all of my 320 KBps MP3 and FLAC can be transferred to my iPhone through iTunes lossless ?

post #10 of 11

I just purchased an iPhone and I have not yet attempted to put any music on it except music which has been previously purchased from the iTunes Store. Interestingly, some music and music videos purchased from the iTunes Store are, it appears, not downloadable to my iPhone. An example is Owl City's Fireflies. There are about a dozen more I have not been able to  get onto the phone. At any rate, I'm too ignorant about the matter today to help you. I'm still somewhat confused myself.

post #11 of 11

O.K., I'm no longer confused. Connecting via USB my iPhone to computer running iTunes copying music at whatever format it's stored in iTunes is a drag and drop proposition. If you do not want the music to be down-sampled to 128k you will need to uncheck the box that controls down-sampling on the sync page of the set up registration.

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