Learning from the past, my audio experiences

[kornchild2002]

shabbs and Teqnilogik beat me to it (by about a week).

As previsouly stated, once you get up to 192kbps and higher, all encoders start to sound the same. That is why I recomend using iTunes AAC at 128kbps VBR or 160kbps VBR. If not then you just might as well rip to iTunes mp3 or Lame mp3 at 192kbps or -V 2 (~190kbps VBR) respectively because you won't be taking advantage of the AAC format.

[Teqnilogik]

I agree. Theoretically, AAC at 192 kbps should be higher quality but perceptually (which is most important) it really isn't significantly (if any) higher quality than MP3. The human ear finds it very hard to distinguish 192 kbps encoded files from the originals in most cases. Most modern MP3, AAC, etc encoders will generally produce transparent quality at 192 kbps. Just do an ABX test between formats at 192 kbps and I can pretty much guarantee you won't be able to tell a difference. I can barely tell a differnece between a 128 kbps AAC and the original quality, LOL. So follow Korn's advice, if you want 128 kbps - 160 kbps go with AAC. If you want anything higher than that just use MP3 since it won't be worth using AAC. Even ify ou use the iTunes MP3 encoder at 192 kbps you will get very nice results. iTunes is more convenient and if you like that don't worry too much about the quality of 192 kbps MP3 rips with iTunes. Yes, LAME is better quality and has a much better VBR system. Personally, the only thing missing from the iTunes MP3 encoder is a nice VBR mode. I would be happy if the iTunes MP3 encoder simply did one thing when VBR is selected. That is, to lower the bit rate to 32 kbps when it encounters silence in a song. I could live with the rest of its VBR short coming (with the min. bit rate setting) if it would just do that to save space on tracks where there are long pauses (mostly on hidden tracks).

[trachshack]

kornchild 2002,

Thanks for a very informative post. When I bought my first iPod and ripped my CD's I simply used the default (AAC 128) setting. This was in December of 2004. I have now learned from you and others that since then, Apple added a VBR option to iTunes. On one hand I'm glad to hear your opinion that AAC at the 128 import rate is fine. On the other hand, I'm wondering if it would be worth it to re-rip everything using 128 VBR. (I am using a 60GB Video iPod and a new pair of really good earphones...UE super.fi 5 Pro...which are a major improvement, especially using the treble boost eq, over my old ER6i's.) In your opinion, should I re-rip using AAC VBR? Some threads seem to say that the VBR function in iTunes is pretty limited, but I am absolutely willing to do it if it would make a difference.

Thanks.

[kornchild2002]

I wouldn't go back and re-rip to VBR AAC. The VBR AAC implementations in iTunes are limited. The bitrate can fluctuate up to 30kbps over the selected VBR bitrate and 30 kbps below (I think, it may be a little more or a little less). This probably won't add a lot of audible quality. I am plesently surprised by the iTunes 128kbps VBR AAC setting though. I have tested a bunch of tracks and their overall average bitrates normally come out to 148kbps.

You can re-rip as iTunes has improved the quality of their AAC encoder since December but it probably isn't enough of a quality increase to cause one to re-rip all their CD's (unless you have a small CD collection).

[kornchild2002]

Just giving eveyone an update. I recently went to two festivals during the past couple of months. One was Ozzfest 2006 and I was holding the front rail for the entire second and main stages. My ears were ringing for 2 days after that concert. Then, I went to the Family Values Tour 2006 and again, I was about 2 feet from a 130 db speaker set. My ears rang for 2 days after that concert as well. Ozzfest lasted for 13 hours and Family Values lasted for 9 hours.

Since these two concerts, I decided to go back and try some more ABX tests. To my surprise, I keep failing them. I cannot distinguish between the source CD or a 128kbps VBR iTunes AAC or a -V 4 --vbr-new Lame mp3 (3.97b3). I think I really damaged my ears. Hence forth, I have decided to save a lot of room on my iPod and go back and convert all of my lossless files to -V 4 --vbr-new with Lame 3.97b3. The resulting files will be around 140-170kbps VBR and will free up a lot of space on my iPod. The days of me using -V 2 are over simply because it is overkill for my ears. I will still recomend using the Lame mp3 encoder but I will now suggest using either -V 2 or -V 4 depending on the equipment, listening environments, and the listening tests of said users.

Just giving you all a update and a warning. When they suggest using earplugs at concerts, they really mean it.

[crash613]

Korn,

very nice column.. well written. i have one question though. I have used EAC for ever, but you lose me when you keep referring to v2 and v4. What do these terms mean?

thanks.

mike

[mnhnhyouh]

Instead of hitting either a constant bitrate, or an average bitrate, the v settings aim for a specific quality, and use as many bits as are necessary to achieve it.

h

[crash613]

Ok. i kind of get it.. it is not exactly VBR but kind of a VBR on autopilot. correct?

So one more question.. how do i use it? My educated guess is that it goes into the "ADDITIONAL COMMAND LINE OPTIONS." under eac dropdown--> Compression options ---> External Compression tab.

is this correct?

if so how would you write it? "-V 2 --vbr-"
w/o the quotes. V (space) 2 (space) -- (two dashes) vbr- (one dash)
How would that work with the other settings i have in there?
-b 256 -m s -h
is there a "V" setting to make the files around 256?

sorry about all the questions. but this is intriguing.

[shabbs]

Take a look at Teq's EAC guide for examples of the LAME command line switches (the "V" switches) for use with EAC:

http://www.teqnilogik.com/tutorials/eac.htm

Cheers.

[kornchild2002]

Originally Posted by crash613

Ok. i kind of get it.. it is not exactly VBR but kind of a VBR on autopilot. correct?

So one more question.. how do i use it? My educated guess is that it goes into the "ADDITIONAL COMMAND LINE OPTIONS." under eac dropdown--> Compression options ---> External Compression tab.

is this correct?

if so how would you write it? "-V 2 --vbr-"
w/o the quotes. V (space) 2 (space) -- (two dashes) vbr- (one dash)
How would that work with the other settings i have in there?
-b 256 -m s -h
is there a "V" setting to make the files around 256?

sorry about all the questions. but this is intriguing.

Look at the link that shabbs gave you. Lame changed their language. Before, with Lame 3.96.1 and previous versions, they used --alt-presets. Now, everything has been changed with different -V quality settings. The purpose behind these is that you will be given a quality instead of a know bitrate. For example, with the command (without quotes) -V 2 --vbr-new, the target bitrate is supposed to be around 190kbps VBR but I had some songs that came out to 140kbps VBR and some songs came out at 267kbps VBR. It just depends on song complexity.

The -b command is to get a average bitrate (ABR). This is not really recomended as you are tweaking the encoder to get a known bitrate instead of a know quality. Not all songs need to be encoded at the same bitrate to achieve the same quality. Rap, pop, and many acoustic songs can be encoded at lower bitrates and still retain quality.

I recomend going with -V 2 --vbr-new, -V 0 --vbr-new would achieve around 256kbps VBR. However, I really suggest that you download a program called foobar2000 and do some listening tests. Conduct a blind ABX test with a source lossless file ripped right from the CD and a mp3 encoded at -V 4 --vbr-new (~160kbps VBR). If you have already done this then good job. I suggest -V 4 simply because many people have problems with it. If you are using the iPod stock headphones then you will not be able to distinguish between the source CD and even a 128kbps VBR iTunes AAC.

[crash613]

thanks for the info guys.. between Korn's explanation and the link provided by Shabbs, I learned quite a bit in the past several hours. (probably more than i will ever need to know about ripping)

thanks again.

[shabbs]

Originally Posted by crash613

thanks for the info guys.. between Korn's explanation and the link provided by Shabbs, I learned quite a bit in the past several hours. (probably more than i will ever need to know about ripping)

No worries. You can thank Teq for the info in the link I provided.

[kornchild2002]

Looks like I am sellilng myself to Apple. I have recently been purchasing a bunch of music off of the iTunes Music Store. People give me iTunes gift cards for my birthday and for Christmas. I had about $200 backed up in unspent money. I decided to go ahead and spend it all on music that I always wanted but either could not find or the CD's were just too old and expensive. Now, I seem to keep getting at least $25 in iTunes gift cards about once per month. I already had about 400 purchased tracks ever since 2003 but adding about 235 tracks (the amount I have downloaded so far) made my iTunes AAC library a pretty good size. Additionally, when I was off and away, my notebook lacked EAC and I borrowed about 100 CD's from a friend and used my laptop to rip them to the iTunes AAC format at 128kbps VBR. I did not have the space for anything but 128kbps VBR iTunes AAC as my hard drive was filled with ripped DVD's that I needed to back up. Roughly 60% of my 6000+ library was encoded to 128kbps VBR iTunes AAC.

I have finaly decided to just finish it all of and convert my lossless library to 128kbps VBR iTunes AAC. As previously stated, I was already switching to a lower bitrate and I was still frustrated that I could only fit about 125 songs on a mp3 CD. It is just easier for me to plug in my iPod and play the songs off of it. Additionally, my recent blilnd ABX tests are pretty lame as I can't even distinguish between 128kbps iTunes AAC and the source CD. I might as well switch to a good format that is built righ into iTunes just to make my life easier.

I still plan on recomending EAC and Lame to everyone but most of my library was already in the 128kbps iTunes AAC format so I might as well of just finished it all off.

[shabbs]

Originally Posted by kornchild2002

Looks like I am sellilng myself to Apple.

And another one bites the dust...

One day, I will be the only one running EAC/LAME!

Heh heh.

[Code Monkey]

Originally Posted by shabbs

And another one bites the dust...

One day, I will be the only one running EAC/LAME!

Heh heh.

Does EAC>FLAC>LAME still count?