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bigpoppamac31

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Aug 16, 2007
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So I'm wanting to re-import my songs from CDs into iTunes in AAC 256k. I'm curious whether it's better to have VBR on or off and what would be the benefit either way?
 
So I'm wanting to re-import my songs from CDs into iTunes in AAC 256k. I'm curious whether it's better to have VBR on or off and what would be the benefit either way?

The idea with Variable Bitrate is that, from your average of 256kbps for a track, there will be times when the sound can benefit from a higher bitrate (complex sound) and other times when simpler sound doesn't need such a high bitrate. So, in theory, for a given file size, you should get better sound reproduction in the more complex moments. This seems an eminently reasonable thing to do. The downsides are that older hardware may not know how to handle VBR files, and it might take a little longer to encode the files in the first place.
 
Personally when importing music from CDs I import in a lossless format and then re-encode to a lossy format for use on mobile devices. So I'd have Apple Lossless for archiving purposes and AAC for use on iPhone / iPad / iPod / whatever.
 
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Personally when importing music from CDs I import in a lossless format and then re-encode to a lossy format for use on mobile devices. So I'd have Apple Lossless for archiving purposes and AAC for use on iPhone / iPad / iPod / whatever.

Well I could do that but I don't think I have enough space on my hard drive for thousands of uncompressed music files.
 
An MP3 is about 10% of the original, ALAC (or FLAC) are about 50-60% of the original. Roughly.

An AAC file is about twice the size of an MP3 of the same bit rate. Apple Lossless is around 3 times the size of an AAC file. I'm really not sure what to go with (AAC or Apple Lossless) and whether to use VBR or not. Apple Lossless doesn't give the option for VBR but AAC does.

Also I noticed that in iTunes in the iPhone settings there is an option to "Covert higher bit rate songs to 128k,192k,256k AAC. Does that simply convert the song prior to sending it to the iPhone or would I then have duplicates on my Mac in iTunes??
 
An AAC file is about twice the size of an MP3 of the same bit rate. Apple Lossless is around 3 times the size of an AAC file. I'm really not sure what to go with (AAC or Apple Lossless) and whether to use VBR or not. Apple Lossless doesn't give the option for VBR but AAC does.

Also I noticed that in iTunes in the iPhone settings there is an option to "Covert higher bit rate songs to 128k,192k,256k AAC. Does that simply convert the song prior to sending it to the iPhone or would I then have duplicates on my Mac in iTunes??

Apple Lossless is lossless as the name implies. If you want your music to sound exactly the same as it does on the CD then Apple Lossless is the only option. AAC 256k comes pretty damn close and saves a lot of hard drive storage but it does lose some of the information in the original music because it is a lossy format. There is no such thing as VBR for lossless file formats because they aim to make an exact duplicate of the music from CD.

If your files are already in AAC or MP3 you won't get any extra quality though by converting them to Apple Lossless you'll just end up wasting hard drive space. The only time it is worth using Apple Lossless is if you have the original on CD (or Vinyl).

If you convert higher bit rate songs to AAC then it will just do it before copying to your iPhone and won't clog up your Mac.
 
Apple Lossless is lossless as the name implies. If you want your music to sound exactly the same as it does on the CD then Apple Lossless is the only option. AAC 256k comes pretty damn close and saves a lot of hard drive storage but it does lose some of the information in the original music because it is a lossy format. There is no such thing as VBR for lossless file formats because they aim to make an exact duplicate of the music from CD.

If your files are already in AAC or MP3 you won't get any extra quality though by converting them to Apple Lossless you'll just end up wasting hard drive space. The only time it is worth using Apple Lossless is if you have the original on CD (or Vinyl).

If you convert higher bit rate songs to AAC then it will just do it before copying to your iPhone and won't clog up your Mac.

Most of my music is from my CDs. Most everything else is iTunes purchases. I'd only be reimporting all my CDs. It seems Apple Lossless would almost triple the amount of space my music takes up on my SSD. But I have more than enough space to do it.
 
An AAC file is about twice the size of an MP3 of the same bit rate.

No, it's approximately the same size. Generally AAC is slightly bigger but not even remotely twice the size.

Apple Lossless is around 3 times the size of an AAC file.

Well, that depends on the bitrate. Around 3 times the size of AAC at 256K, yes. Probably closer to 3.5X on average.

Apple Lossless doesn't give the option for VBR

Because it's lossless; if it removed any audio data for any reason, that would defeat the purpose of being lossless.

Also I noticed that in iTunes in the iPhone settings there is an option to "Covert higher bit rate songs to 128k,192k,256k AAC. Does that simply convert the song prior to sending it to the iPhone or would I then have duplicates on my Mac in iTunes??

You don't have duplicates on your Mac. The version on the phone is what's converted.

--Eric
 
An AAC file is about twice the size of an MP3 of the same bit rate. Apple Lossless is around 3 times the size of an AAC file. I'm really not sure what to go with (AAC or Apple Lossless) and whether to use VBR or not. Apple Lossless doesn't give the option for VBR but AAC does.

Also I noticed that in iTunes in the iPhone settings there is an option to "Covert higher bit rate songs to 128k,192k,256k AAC. Does that simply convert the song prior to sending it to the iPhone or would I then have duplicates on my Mac in iTunes??

First, files with the same bitrate have the same size. AAC at same bitrate has much higher sound quality than MP3, so you should use AAC.

Uncompressed CD = 1411Kbit/sec = 10.6 Megabyte per minute.
Apple Lossless = usually around 700 Kbit/sec = 5.2 Megabyte per minute, depending on the music.
MP3 320 KBit = 2.4 Megabyte per second.
AAC 256 Kbit = MP3 256 KBit = 1.9 Megabyte per minute.
AAC 128 Kbit = MP3 128 KBit = 0.96 Megabyte per minute.

What VBR does: Some music is easier to compress, and some is harder to compress. If you use the same compression rate for all the music, then some will sound worse and some will sound better. VBR uses more bits for music that is harder to compress, and fewer bits for music that is easier to compress. Overall this gives better quality at the same average bitrate. Therefore you should use AAC VBR.

Apple Lossless is always VBR. Lossless compression must be lossless, that is perfect quality. A lossless compressor doesn't have the choice to produce lower quality to save some bits. It always uses exactly as many bits as needed to create perfect quality, sometimes more, sometimes fewer.

The option "Convert higher bit rate... " converts the music while downloading it to the iPhone. Nothing is duplicated on your drive. The download is a lot slower because it has to compress the music first, so don't use it if you change the music on your device all the time. Otherwise it's fine, just be aware that filling a 64 GB iPhone with 128 KBit music will take ages - do it overnight.

And if you have music that is already compressed, don't change it. For example, I said that AAC has higher quality than MP3. However, if you convert say 128 KBit MP3 to 256 KBit AAC, the result will actually have worse quality than the original, that is worse than 128 KBit MP3, even though you used double the space.
 
First, files with the same bitrate have the same size. AAC at same bitrate has much higher sound quality than MP3, so you should use AAC.

Uncompressed CD = 1411Kbit/sec = 10.6 Megabyte per minute.
Apple Lossless = usually around 700 Kbit/sec = 5.2 Megabyte per minute, depending on the music.
MP3 320 KBit = 2.4 Megabyte per second.
AAC 256 Kbit = MP3 256 KBit = 1.9 Megabyte per minute.
AAC 128 Kbit = MP3 128 KBit = 0.96 Megabyte per minute.

What VBR does: Some music is easier to compress, and some is harder to compress. If you use the same compression rate for all the music, then some will sound worse and some will sound better. VBR uses more bits for music that is harder to compress, and fewer bits for music that is easier to compress. Overall this gives better quality at the same average bitrate. Therefore you should use AAC VBR.

Apple Lossless is always VBR. Lossless compression must be lossless, that is perfect quality. A lossless compressor doesn't have the choice to produce lower quality to save some bits. It always uses exactly as many bits as needed to create perfect quality, sometimes more, sometimes fewer.

The option "Convert higher bit rate... " converts the music while downloading it to the iPhone. Nothing is duplicated on your drive. The download is a lot slower because it has to compress the music first, so don't use it if you change the music on your device all the time. Otherwise it's fine, just be aware that filling a 64 GB iPhone with 128 KBit music will take ages - do it overnight.

And if you have music that is already compressed, don't change it. For example, I said that AAC has higher quality than MP3. However, if you convert say 128 KBit MP3 to 256 KBit AAC, the result will actually have worse quality than the original, that is worse than 128 KBit MP3, even though you used double the space.

Thanks for the info. If I were to use the "Convert higher bit rate..." option I'd covert to 256k AAC. Not 128k. But I'd only use that feature if I end up importing my CDs with Apple Lossless. Otherwise there's no point. You also said that "files with the same bitrate have the same size". I'd argue that with the condition of the length of the song. Most songs seem to fall within 3-4 minutes but some are under or over that. That would mean the file size would vary depending on the length of the song. I have a 32GB iPhone 5S and right now I sync only select playlists. I still have about half of that 32GB free right now. The playlists on my iPhone mirror those on my iPod nano. I always have both with me. If one dies and needs to be recharged I have the other to continue listening to music.
 
Between CBR and VBR: 256kb/s VBR is higher quality than 256kb/s CBR because the VBR can basically be any bit rate (0 to 320kb/s). Between 320kb/s CBR and 256kb/s VBR the sound quality should be more or less identical (if using the same codec, say MP3) but the resulting file size is smaller with VBR. 320kb/s is always CBR.


To OP: Unless you have some decently good audio system you are unlikely to here the difference between lossless and AAC 256kb/s VBR. If you are going to archive your CDs and throw them away, consider lossless for that (and external drive). But if you are going to keep the CDs and you are low in disk space, which usually tends to be the case with SSDs, AAC might be the better option. Sooner or later you'll run out of space on that drive.
 
Also, there's nothing inherently lossless about WAV files, since they can contain MP3 data. Like how M4A files can contain ALAC (lossless) or AAC (lossy) data.

--Eric
 
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