Wondering about the difference between an AAC @ 128kbps and an mp3 @ 320kbps

[ghost_recon88]

So, I had my whole CD collection ripped ahead of time in anticipation of getting an iPOD. So, I ripped them all at 320kbps with the mp3 format. So, I'm on the web, and I see people hyping up the AAC format, which by defaults rips @ 128kbps in iTunes, and the files are a ton smaller. Now, while I'm not too concerned about space, I was wondering if the 128kbps AAC is comparable with a 320kbps mp3? A few people on the web seem to think so, and the AAC is a much much smaller file than the mp3 is. So, does anyone know, or is it all a matter of prefference?

[R4z0r4mu5 Pr|m3]

don't know about the quality comparison but the mp3 format is more universal unlike AAC or WMA

[SuperFarStucker]

The codecs all have different strengths and double blind listening tests generally find AAC tracks encoded with iTunes to be superior to mp3 at an equal bitrate. If you don't train your ears to listen for compression artifacts they are mostly unobtrusive on both codecs. I usually encode tracks using -aps lame, even though aac offers better quality, because aac is not implemented on all portable devices. a portable device without mp3 would be suicide, even apple knows this :)

wma is generally found to be utter crap.

[Zim2411]

AAC is a much more advanced codec than mp3, and while I personally wouldn't use 128, 192kbps AAC should be perfect. If you are getting an iPod and are planning to use iTunes, than compatibility is of course not an issue.

Personally I prefer ogg vorbis for a lossy format, as the quality is excellent, it's gapless (which CBR mp3 is not, unless it was fixed in LAME) and my Rio Karma plays it.

[Echo_]

first what headphones are you using

and maybe try vbr (variable bit rate) to save space on mp3 and i think they have vbr aac as well

[ghost_recon88]

Actually, after looking at my collection, I'm not worried about space anymore. And I can't find any rippers that support 192kbps AAC. Stinkin iTunes only uses the 128kbps mode.

[Avatar28]

Well I found a codec quality comparison a few months ago (linky (http://www.extremetech.com/article2/0,1558,1561918,00.asp)) and the results from it suggested that at lower bit rates (64k) MP3 sucks but that once you get to 128k it evened out more. Unfortunately they didn't go any higher than 128k. Regardless, you're encoding your MP3s at 3 times the bit rate of the AAC files. AAC is likely somewhat better than MP3 for a given bitrate but nowhere NEAR three times better. Typically it's 1-2 steps difference with any codec over MP3, e.g. a 128k AAC is roughly equal to a 160-192k MP3.