iTunes and lossless - an interesting discovery using MP3 VBR Settings

[hybridauth_Google_116099484997176958150]

Hello,

Firstly, this mail is a entry is a bit long but hopefully interesting

I have the misfortune to now be able to distinguish between MP3 at 320kbs and FLAC (ALAC) recordings. The difference between ALAC and MP3 at 320 kbs is not great it must be said but a worthwhile difference and, in some cases, a more significant difference (later).

My system is a Sony NWZ-A15 control unit outputting to an OPPO-HA2 DAC via the digital-out cable. This is the neater custom one available from Amazon.com - rather than the official Sony WMC-NWH10 cable connected to the supplied OPPO USB cable – which is messy. I have previously used the Fiio L5 cable but this only gives analogue out. Headphones were OPPO PM-3’s – so a decent setup.

Anyway, I kind of like MP3, as it’s more portable and smaller in size than a FLAC or ALAC file. The reason I use ALAC over FLAC is simply easier conversion via iTunes and for no other reason.

Data is synced to my Sony via Allway Sync which neatly handles any changes.

So, I decided to experiment with different file formats to observe any differences with them. This was to decide whether to re-rip my entire collection which isn’t a trivial task.

Amongst others, I used OMD’s English Electric which, apart from being a great album (way more mature than their previous poppy stuff) is well recorded.

I used tracks:

02 Metroland

09 Stay with Me

12 Final song (one of the catchiest songs on the album even though the last)

Track 09 is the most interesting especially at around 9 seconds when the song bursts into life with a kind of gurgly synthy bit – and that is the most important part to listen to during testing.

I ripped all tunes from the original CD several times using iTunes as follows:

-1- AAC – the default, with iTunes Plus setting (the best)

-2- MP3 at 320 Kbs

-3- Apple lossless

There is a 4th one I will detail in a bit.

I then isolated those tracks into a single directory and used a track number such that I could quickly flick between each track using the player to detect any differences. Program mp3tag was used for this.

The results are as follows:

ALAC compared to AAC. Unable to detect any differences.

ALAC compared to MP3. Difference detected at gurgly bit. It sounds fuzzy and indistinct.

Everything as expected so far except perhaps AAC which I was surprised at.

Finally, I decided to do one last test (for fun) using settings below in iTunes.

Stero Bit Rate320Kbs

Use Variable Bit Rate Encoding (VBR) - Checked

Quality - Highest

I would not expect any differences to standard MP3 at 320Kbs.

Wong! This is the one that most confuses me! It sounded better than ‘normal’ MP3 at 320Kbs and as good as ALAC. At the gurgly bit, this was a clear as ALAC and both myself and a friend could not detect a difference.

My conclusions

Standard MP3 is unable to resolve complex passages sufficiently. AAC handles these well along with VBR. Note that VBR appears as ‘320kbs’ when used with settings above rather than the mixture of sporadic bit rates you normally get.

Final thoughts

From my point of view I would therefore like to re-rip all of my CD’s with the above VBR settings but I don’t propose to do this until I am absolutely certain that my observations are correct.

Could someone possibly explain what is going on with the VBR bit and, perhaps, try this yourselves? And can you (honestly) detect a difference between that and ALAC/FLAC against my VBR settings?

Hoping you can put me out of my misery!

 

[hybridauth_Google_116099484997176958150]

Hi Chebby and thanks for your reply. Yes, I know what you mean with those lucky people who can hear minute differences! The amount of time I've spent listening to various formats over the past year runs into many, many hours. It's important to remember it's about the *music* at the end of the day ....

However, to me hi-res isn't worth it. Personally I think it's just a way to get additional sales and, from my experience, I can't tell any difference so no benefit to me, sadly. Good luck to those that can tell the difference.

It's also a compromise between sound quality and space.

Having converted a number of items to ALAC and compared closely with different formats/settings, I think anything that gets relatively close to ALAC is fine and good enough for me. I think your VBR idea is excellent.

All the best.

 

[chebby]

Hoping you can put me out of my misery!

No I can't.

I chose 320k AAC VBR as my default iTunes rip setting years ago. (I even used 320k before VBR was available for it.)

I have mentioned it (correction, got quite boring about it) frequently.

It won't convince anybody so don't expect many supporters of 320K AAC VBR. For a start it's Apple so therefore 'evil'. We also have a lot of 'Golden Ears' around here who can hear a gnat combing a knot from it's eyebrows in the middle of a Wagner opera. We also have a lot of people who are invested into so-called high-res 24bit/32bit/96kHz/192kHz downloads and then, finally, a lot of hipster turntable dudes who love the sound of diamond scraping on plastic to the exclsion of all else.

There will be one-or-two dealers on your case too.

 

[hybridauth_Google_112658120703314018098]

However, to me hi-res isn't worth it. Personally I think it's just a way to get additional sales and, from my experience, I can't tell any difference so no benefit to me, sadly. Good luck to those that can tell the difference.

Not really a surprise. Higher sampling rates allow for higher frequencies to be reproduced (into the inaudible ultrasound range). But can you hear these frequencies?

Personally I can't hear anything above 17khz (so I don't hear the "Mosquito" tone - the security device designed to annoy teenagers). Those under 25 or those with exceptional hearing may hear up to 20khz or a bit more, but no one can hear much above that. Some test tones online here - http://www.audiocheck.net/audiotests_frequencycheckhigh.php

 

[abacus]

AAC & mp3 are lossy formats as they take away some of the sound to make the file smaller, however once taken away it cannot be put back.

ALAC & FLAC are lossless therefore they are a 100% copy of the origiinal, nothing added, nothing taken away.

As to whether you can tell the difference, then this will be determined by the quality of your system, room & ears, which only you can decide.

For streaming I would not pay extra over Spotify Premium as the difference between this and Tidal is minimal.

For storing my own music (CD,s for example) I would always choose lossless, as should I wish to convert to another format at some time, I know I will be converting from a 100% original, and in a format that allows bulk conversion without needing to perform the laborious task of ripping the CDs again, which is something you would have to do if you were converting from a lossy file. (Unless you were happy to miss out the information that was removed during conversion to the lossy format)

Hope this helps

Bill

 

[hybridauth_Google_116099484997176958150]

Personally I can't hear anything above 17khz (so I don't hear the "Mosquito" tone - the security device designed to annoy teenagers). Those under 25 or those with exceptional hearing may hear up to 20khz or a bit more, but no one can hear much above that. Some test tones online here - http://www.audiocheck.net/audiotests_frequencycheckhigh.php

I'm getting on a bit so there is no danger of being able to hear those high frequencies, sadly! Thanks for the response.

 

[hybridauth_Google_116099484997176958150]

AAC & mp3 are lossy formats as they take away some of the sound to make the file smaller, however once taken away it cannot be put back.

ALAC & FLAC are lossless therefore they are a 100% copy of the origiinal, nothing added, nothing taken away.

As to whether you can tell the difference, then this will be determined by the quality of your system, room & ears, which only you can decide.

For streaming I would not pay extra over Spotify Premium as the difference between this and Tidal is minimal.

For storing my own music (CD,s for example) I would always choose lossless, as should I wish to convert to another format at some time, I know I will be converting from a 100% original, and in a format that allows bulk conversion without needing to perform the laborious task of ripping the CDs again, which is something you would have to do if you were converting from a lossy file. (Unless you were happy to miss out the information that was removed during conversion to the lossy format)

Hope this helps

Bill

Hi Bill, you speak a lot of sense. I did 192kbs originally and just recently all at 320kbs. I was kind of shocked to hear a difference with ALAC but it was in a controlled environment. If you simply played both 320kbs and ALAC through your system I doubt anyone could positively tell the difference.

My original comment was more to do with why *was* there a difference with a straight iTunes 320kbs rip and a VBR rip using encoding option set to the highest quality? I'd like to know what is going on, there!

Maybe you could try this and compare to some of your lossless rips?

I think I will do what you do and rip lossless for my favourite items (I have some rare Logic System CD's for example ) and settings above for the rest. Cheers Bill, Gary

 

[hybridauth_Google_116099484997176958150]

Okay, I understand now. It is the 'Stero Mode' field being set to 'Joint Stero' (rather then 'Normal') that makes the difference. So nothing to do with the VBR settings directly - except that VBR sets the mode to 'Joint Stereo' by default.

It certainly makes a critical difference with sound - but I'm beginning to agree with Bill in that all of these problems go away with lossless.

 

[Xanderzdad]

Hi

The VBR (Variable Bit Rate) sets an average bit rate (of 320 in your case), using more for the complex sections of music and less for others.

This means it actually retains more detail where needed thereby creating a better quality recording overall - hence why it sounded better.

 

[hybridauth_Google_112658120703314018098]

Yes it will probably peak at higher bit rates than 320 Kbps if it is using VBR. Some encoders can use higher bit rates, for example I just made this as a test file using the FAAC encoder. I just set it to a quality setting of "500" and it's basically made a 505 Kbps VBR file (which peaks at 541 Kbps). I can't tell the difference from the original WAV, personally.

 

[hybridauth_Google_116099484997176958150]

Thanks both Xanderzda and Jon.

I see. So, as I am using VBR set to the highest quality setting, it can still go higher if needs, yes? I still feel the 'Joint Stereo' has something to do with it. I ripped at 320Kbs with 'Joint Stereo' set and certainly sounds more like lossless (VBR was unchecked).

Apple should really give you a proper guide to getting the best out of the various formats - although I suppose for MP3 they don't care as they would rather you use AAC (which did sound good, I have to say).

I think this whole ripping area is a minefield for most people - with different encoders working differently to each other. As one of the other respondants said, maybe the solution is to use lossless? Anyway, many thanks for taking the effort to reply both of you. All the best.

 

[hybridauth_Google_112658120703314018098]

No worries Mike, it's a pleasure. AAC is considered superior to MP3, in terms of compression efficiency and subjective listening tests at a given bitrate. Incidentally although Apple use it, AAC is not an Apple proprietary format, but part of the MPEG specifications (it's used for HDTV etc.).

Maybe joint stereo can have a large effect? My understanding of it is that it aids compression by combining data that's common between the left and right channels to improve compression efficiency, rather than encoding two discrete channels. Logically if you have discrete stereo channels in a 320 Kbps recording, each will be 160 Kbps on average. Wheras if you combine the common sounds from the left and right channels and encode that as one, and a lesser amount of data to describe the differences between each channel, potentially it is a much more efficient way of doing it. I think

 

[iMark]

Phew. I'm glad I decided 10 years ago to rip all our CDs to Apple Lossless (ALAC). Never any worries about loss of sound quality while streaming to our Airport Express. For my iPod Nano (16GB) I now downsample everything to AAC 256 kbps on the fly because those files take about a third of the ALAC files. I know it's a compromise, but having three times more albums with me while travelling is also great.

No complaints here about iTunes. I know it's bloated, but it does for us what it needs to. And the Mac version is pretty good, unlike the Windows version.