Digital audio formats / iTunes help (pleeze)

I think I know the answer, but I’m going to ask anyway.

I have around 6000 digital songs, probably >80% that were copied from CDs I own (the others, mostly iTunes downloads). Previously, I used digital music only on my iPod, almost exclusively when working out. Therefore, I didn’t much care for the quality of the files (and used whatever the default settings are).

So, today I bought myself a nice Kenwood receiver for my vehicle, along with a speaker upgrade. I tried the radio, sounded good. Tried a CD, sounded awesome. Then, I hooked up the iPod; I guess you can tell, I was disappointed in the sound.

I’ve only tried a couple of songs, but I suspect all the ones I grabbed from a CD will be similarly sub-par in audio quality.

On to my question. Short of re-ripping the hundreds of CDs at a higher bit rate, is there anything I can do to the music in my library to improve the sound quality?

If I do re-rip, what are my specific options? Is there much difference in, say, the highest quality and the second-highest?

Hard drive and iPod disc space are not a problem.



ETA: I just check my music files. Here is what is shown on a typical song:

Kind: MPEG audio file
Format: MPEG-2, Layer 3
Size: !.8 MB
BIt Rate: 64 kbps
Sample Rate: 22.050 kHz

You can’t make a steak out of a sausage - once your music has been degraded by lossy compression, there’s little you can do to improve it.

64kps! Shame on you.

Yeah man, 64kbps? Amazon sells their mp3s at 256kbps with a 44khz sample rate.

I would say that “most audiophiles wouldn’t even accept that” but all of the audiophiles I know won’t even accept MP3 :slight_smile:

The maximum conversion rate on my home recording program (which isn’t even a “professional” level program) is 320 kbps. The minimum is 96 kbps.

Sorry to tell you, but 64 kbps is ringtone quality.

I knew I was in for a scolding.

So I’m probably in for a whole lotta re-ripping. If someone could advise me on which specific settings to use within iTunes, I’d totally appreciate it.

I see my options are:
Import using:
AAC Encoder
AIFF Encoder
Apple Lossless Encoder

iTunes Plus
High Quality (128 kbps)

Whatever program you use to rip the files will have an options setting, there you will find out what options are available. As to which one to use, rip the same song at different bitrates and play them back in your car. You’ll be able to tell the difference from the poor rate you use and a better one. Use the one you like, but if disc space really isn’t a problem, use the highest rate available. You might also consider a lossless format, but I suspect if you do that then disc space may become an issue.

128 is better than what you have, but you may be able to hear a difference between that and a higher rate. I use 256 myself, but I use the mp3 format. I’m not familiar with apple formats, 128 may be just fine.

If space is not an issue, use Apple Lossless. It’s about 1/2 the size of raw CD format, and 100% of the quality (like ZIP for music). You can always convert down from there.

I don’t know much about iTunes (don’t have it), but the only two settings I will use for mp3 conversion are 320kbps or V0 VBR, the latter being the more sensible choice in terms of disk space usage. If you wanted to convert from a lossless format to either 320kbps or V0 VBR, then LAME can help.

Again, I don’t know whether this can help you out with iTunes, someone else can confirm or deny.

OK, looks like it’s not nearly as bad as I feared. A spot check through my library leads me to guess that somewhere between 50 and 75% are 128 or 256kbps; all the lower ones are from the oldest of my CDs, when I first installed iTunes. I must have stumbled upon a couple of these 64’ers when first connecting the iPod in my vehicle.

I did find one, though, that was a mere 40kbps. :o

I’m off to re-load a song at various bit rates and let my ears decide how to proceed. I’m thinking ‘Come Together’ would be a good choice.

Thanks for all the help.

I would use the default iTunes Plus settings, assuming you don’t mind having AAC files. If you want them as mp3, I would use 160kbbs VBR.

256k is a little overkill - if you’re pushing up that high, you might as well go with a lossless format in the first place.

I did my ‘Come Together’ experiment. I agree with JoeH2O: 256k is overkill (at least to my ears). 128 sounds, to me, every bit as good as anything higher.

Also, when I started doing some 'rithmatic, I realized that space would, indeed, become an issue if I didn’t pay attention.

Now, I’m going through my library and jotting down which CDs I have to reload. Amazingly, nearly all my Beatles CDs were at 40k. What a dope I am.

AAC vs. MP3: I read that AAC is an improvement over MP3. Are there any disadvantages to AAC?

Not on an iPod.

Try something with phase shifting in it, such as Ted Nugents ‘Journey to the Center of the Mind’. It’ll sound different at 128 and 256K.
Stuff with hard percussion can also be noticably degraded by low bit rates; mp3 masking in action.
Oh yes, flute music also likes a higher bit rate than seems reasonable for such a simple waveform.

If you are only playing with an iPod, there are no downsides to AAC - you get better audio quality than mp3 for the same bitrate, but the files will be incompatible with a machine that has no support for the format, like a Creative Zen or something similar. All iPods have full AAC support.

Don’t the Creative Zen players now support AAC?

I’ve been re-ripping my CD’s lately and organizing my Itunes library. Personally, I use iTunes to rip at 256 kbps mp3. If only because I don’t know what portable device/situation I will find myself using in the future and mp3 format is universal.

Also 256k is the cutoff point really, any more bit rate won’t do much of anything that is detectable to a normal ear, but 128 can audibly decrease the quality of some type of music/instruments.

As it turns out, they do:

Still debating the 128 vs. 256 decision.

If you have two identical libraries, one ripped at 128 and the other at 256, would the 256 library be (roughly) double the size of the 128?

Or is it more complex than that?

Roughly. I just tried exporting ‘Mean Mr. Mustard’ at 128 and 256 BPS, and got file sizes of 1,066,655 and 2,133,287 bytes respectively.

I rip everything lossless, but I am on the idiotic end of audiophool. With an iPod 256kb/s AAC is very close to lossless. If you go MP3, variable rate makes a quite substantial improvement in the quality/data use. However iTunes doesn’t support it for ripping. (Lossless AAC is a variable rate compressor - which it has to be.) Lossless does at least mean that I can probably never have to rip again. I can (in principle) convert back to raw uncompressed and to any other format I desire as the need arises, and not have to shuffle hundreds of CDs. Fixed rate MP3 is a pretty old and pedestrian quality format.

What you want to do to become an expert is go to HydrogenAudio (dot) Com and prepare to do a LOT of reading. As long as you don’t pirate music, (they destest that over there) you’ll get a lot of help.

Basic fact:

Lossless - No loss in music quality
Lossy - Some music is lost.

If you’re going to re-rip a CD, you might want to invest in an external hard drive and rip all your CDs to lossless. You can get a 1tb external for about $100.

The formats are called codecs, that means COmpression and DECompression. Get it :slight_smile:

The big “Three” lossless formats are FLAC, WavPack and APE. ALAC is from Apple (used with iTunes and iPod) and is also lossless. So which one is better. None. Lossless is lossless it’s all the same. The difference comes in the compression and decompression rates. WavPack is the best for both. APE compresses better but takes longer to decompress. (See Hydrogenaudio for complete details). If you share files, FLAC is the standard

Lossy music means you are losing some quality for the sake of space. For instance a WavPack or Ape or FLAC file compressed the original CD track to 45% to 60% of it’s original size. A lossy format compress it to about 15% of the original size.

The “Big three” lossy formats are mp3, aac (mp4 or m4a <-they’re all the same) and WMA.

Note: WMA produces a lossy codec and also a lossless format. BOTH use the file extension wma. The only way to tell is if you look at the file size.

So which is best? They all are excellent. Lossy formats don’t depend on the codec as much as the compression rate

If you share files, mp3 is the most accepted. You’d be hard pressed to find a player that doesn’t support mp3. WMA is the 2nd most popular lossy codec. AAC (mp4, m4a) is also widespead but not as big as the other two

If you go to hydrogenaudio they have a section that compares the lossy codecs for audio quality. For instance aac(mp4) is better at compression than mp3 so you can use a lower bit rate and get similar results.

For simplification I’ll use mp3 bitrates.

There are three basic type of bit rates. Constant bit rates (CBR), Variable Bit Rates (VBR) and Average Bit Rate (ABR). CBR gives you a bit rate that is the same throughout the song. ABR gives you different bit rates though the song but at the end the average of all the bit rates used in that compression of that particular song is what you specify. VBR shoots for a bit rate you specify, but isn’t tied to it.

For instance in VBR if you want 192 if a part of a song uses less, it won’t go that high and if parts of a song uses more it’ll go higher. Thus if you specify 192 you may get a final of 200kbps. Because the song needed more. With an ABR of 192 you get a final of 192kbps.

VBR is considered the best compromise between space and quality.

At about 192kbps most people cannot tell the difference between an mp3 and a CD. 320kbps is virtual CD quality. 128kbps is considered the least acceptable rate.

Now remember that a few things to consider. Bit rate also depends on the TYPE of music. A heavy metal song uses high bit rates to get quality. On your average pop/rock song you probably wouldn’t notice at 192kbps. But for a heavy metal or classical song, you’d most likely still notice the difference at 192kbps

It depends on the TYPE of music too.

So what’s the best bit rate. NONE. It’s all up to your ear. For me 192kbps using a VBR is indistinguishable from a CD. But this is just me and most of my songs are pop/rock music.

Your bit rate of 64kbps is really the top of the line for SPOKEN tracks. Remember you can go as low as 16kbps for SPOKEN records.

But that’s not all. It’s not only the codec you use but the MAKER of the codec. For instance, not all mp3 codecs are the same. The best mp3 codec is made by LAME. The best aac (mp4, m4a) codec is made by Nero, (iTunes comes in a close second)

So go to hydrogenaudio and look around and you can look at their listening test of the codecs and decide for yourself.

Finally you need to rerip your CDs. EAC (Exact Audio Copy) is the best ripper and get this, it’s free). EAC is a bit more complex than most rippers. It takes about 20 to 30 minutes for newbie to set up. Hydrogenaudio has an excellent guide so you can set it up correctly.

If EAC is just too much try the CD Ripper from DBPoweramp. This is considered almost as good, (but not quite, although some people aruge DBPoweramp’s ripper is as good) as EAC. The thing is DBPoweramp charges for it’s software. DBpoweramp also converts formats with ease. Just right click on the file and convert.

CDEx is another CD ripper that is good but not as good as EAC or DBPoweramp (see tests at Hydrogenaudio for comparisons)

What I did was rip all my CDs to my computer in WavPack (Lossless). Then I use DBPoweramp to convert them to mp4. Then I put those mp4 tracks on my iPod. Then I delete the mp4 files and I still have the lossless tracks.

Again, look around Hyrdrogen Audio. They are very helpful unless your a music pirate. They don’t tolerate that on those forums. But if you ask questions they are very helpful and respectful. The only thing they hate is music piracy. So if you are a pirate of music, don’t mention it :smiley: