[umcloud]

Hey all, looking for your opinions on the most size-to-quality effective bitrate for music encoding. I'm currently encoding at 160 kbps VBR AAC using iTunes. I figured this would strike a good balance between small file size and audio quality. File size has been a big limiting factor, as I've been working with a 40 gig computer hard drive and a 30 gig ipod.

So, what is the bit rate that strikes the best balance between small file size and good audio quality? Note that I'm not looking for transparency, rather the best trade off between the two.

Also note the headphones I have in my sig. I don't currently use an amp, and my highest quality phone will soon be an MS-1. So, if I decide to re-encode some of my music, I'd like it to be a noticable improvement.

Finally, I'd like to continue using iTunes to encode (as opposed to LAME, etc.), due to the convenience factor. So if you could indicate the preferred iTunes mp3 or AAC setting, that'd be very helpful. Thanks in advance for the helpful responses!

 

[Jaska]

I think that you'll get a lot more information about this on Hydrogen Audio than you will on Head-Fi. You might want to take the time to read through their forums for any of the encoders you might possibly use, have a look at the recommended encoders and settings, check out the results of public listening tests, and so on.

 

[umcloud]

Thanks for the link, Jaska. Upon reading a few threads in the AAC forum, I feel better about my encoding choice.

I had thought that iTunes VBR AAC acted like an ABR; that is that 160 kbps VBR AAC encoded at an average rate of 160 for any given file. However, it seems that 160 kbps acts as the "baseline", and the bit rate is increased as necessary. So, any given file will usually have a bitrate somewhat higher than 160 kbps. It also seems that AAC is approximately 30% more efficient than mp3, meaning that a 160 kbps AAC file contains around as much meaningful data as a 210 kbps mp3 file. The comparative sound quality is open to argument, I'm sure.

 

[Rempert]

Even though complete transparency is not your goal, it would still be beneficial to encode a handful of different style tracks all at various settings and AB or ABX each of them against the original. Then you can draw your own conclusion about what bitrate the sound quality really starts to go south at.

Otherwise, my only suggestion is to stick with VBR. And 64 kbps is not going to be enough.

 

[Redo]

Lame MP3 version 3.97

-V 4 --vbr-new

or

-V 5 --vbr-new



However, the only solution once you have everything ripped to change file format is to re-rip your collection (lossy to lossy encoding = yuck). If possible, consider grabbing another HD (HD space is cheap these days) and ripping your collection to lossless. Then encoding from lossless down to a mp3 or aac format is simple and takes no audio quality hit.

 

[Jaska]

Quote:

Originally Posted by Redo /img/forum/go_quote.gif Lame MP3 version 3.97 -V 4 --vbr-new

^^ What I use. ^^

 

[fdjjfdsa]

Truthfully? 128.

It became the standard because below it a reduction in quality starts becoming increasingly obvious, and above it an increase in quality becomes increasingly hard to detect. Even today, I think 128 is the point where you start getting diminishing returns either way. That's pretty much the definition of quality/file size.

Having said that, take a look at a hard drive's marketing sometime. Gigabytes don't mean much for some people, so they usually also list hours of music storage at 128. Find that number on the marketing of a modern hard drive, cut it in half, and it is still going to be insanely huge. Modern hard drives aren't filled up by MP3 files, they are filled up by movies/games.

Use lame at one of the higher quality settings, or use iTunes at 224 or so. It should be transparent, or at least VERY close to it. I know you said you didn't want that, but when you compare the price of your new headphones with the price of that extra 50-75% file size, it seems kinda silly not to.

Also, as someone else pointed out: DO NOT convert one lossy file type into another. One of the biggest downsides of lossy compression is that you are completely stuck with it. You can make new rips from a CD at whatever quality you decide on, but you can't convert Lossy files into other formats/bitrates and expect good results. You probably already knew that, but I figured it wouldn't hurt to point it out again.

 

[smsmasters]

http://wiki.hydrogenaudio.org/index.php?title=LAME

I use OGG at 64kbps with lowpass at 20khz for portable use.

You can use this graph to choose what bitrate would suit your needs.

 

[Redo]

Quote:

Originally Posted by smsmasters /img/forum/go_quote.gif http://wiki.hydrogenaudio.org/index.php?title=LAME I use OGG at 64kbps with lowpass at 20khz for portable use.

Only if all portables supported OGG, it would be the clear winner for portable use. It just sounds so damned good at very low bitrates. So much so, I don't recommend anyone buying a portable player that doesn't support Vorbis.

 

[Pangaea]

Very interested in this type of info too. I am currently re-ripping my Jazz CDs at 256 VBR (AAC). While size isn't a huge issue (I have a 500GB iMac and 60 GB iMod) my music collection grows very quickly so their has to be a threshold of size at some pt. Anyone else had luck with this combo (256 VBR/ AAC)?

 

[smsmasters]

Quote:

Originally Posted by Redo /img/forum/go_quote.gif Only if all portables supported OGG, it would be the clear winner for portable use. It just sounds so damned good at very low bitrates. So much so, I don't recommend anyone buying a portable player that doesn't support Vorbis.

I agree, MP3 can't even compete with OGG at low bitrates. At first I was surprised how good OGG at vbr 64kbits sounds.

 

[umcloud]

I plan on getting a new computer in the fall (iMac w/ 250 gig hd), and will probably re-rip all my CDs in 192 kbps VBR AAC when that happens. After a bit of testing, I found that this was the bitrate at which I couldn't tell the difference between the original and the ripped copy.

 

[hempcamp]

Quote:

Originally Posted by umcloud /img/forum/go_quote.gif I plan on getting a new computer in the fall (iMac w/ 250 gig hd), and will probably re-rip all my CDs in 192 kbps VBR AAC when that happens. After a bit of testing, I found that this was the bitrate at which I couldn't tell the difference between the original and the ripped copy.

Same here. I find 192 AAC sounds identical to lossless, EXCEPT with a very few symphonic pieces.

--Chris

 

[robm321]

Stick with your original choice OP. I think it's the sweet spot.

 

[pedxing]

I usually use between -V4 and -V2, depending on the music and quality of recording.