I've been reading lots of threads in this and the AAC forums and I'm still having trouble deciding whether I should use standard or extreme (both of which seem to be recommended here). I'm using iTunes-LAME 2.07 with LAME 3.90.3 since I'm on a Mac. Encoding time is not an issue at all for me and I will be probably be using some good quality headphones (shure e3c or etymotic er-6i) with my iPod and PowerBook. I would also like to leave open the possibility of listening to my music on some high quality speakers or better headphones (e.g. etymotic er-4p). I think another good choice might be 224 AAC. Any suggestions? Thanks in advance for the help.

Edit: I apologize in advance if there is a thread that already answers a question just like this. If there is one I sure couldn't find it after searching for a long time.

I suggest researching ABX and/or ABCHR so that you can do your own test to determine what bitrate is right for you. I could give you my own opinions on what I think should be suitable, however, it is very unlikely that you hear the same way that I do (or anyone else on this form does for that matter) so I highly recommend that you do your own testing to find out.

thanks musicman. the only problem is that i don't have the headphones just yet. i was still hoping to get other people's advice just to make sure that i'm starting off in the right direction. for example, is it extremely common for the sound to become transparent at 192 kbps AAC thus making 224 kbps AAC overkill (i know different people respond differently, but i'm interested in the majority of people who appreciate good sound and have good ears)? or would i be better off with AAC or MP3? things like that so i don't have to test a ton of possibilities. i was hoping i could get an actual response from people who can pick up on subtle differences because i think it's likely that after a while i'll demand higher quality from my music and i don't want to have to go back and rerip all of my CDs again. thanks!

This may not apply to you but I have recently bought a prtable mp3 player and have had to experiment with transcoding to fit more songs.

Mp3 to mp3 seems to be a worst case scenario. The original files are great but shrinking them down makes them unlistenable.

Mp3 to ogg or aac is better. Ogg to mp3 sounds good too. Haven't looked at AAC to mp3 as yet.

that's exactly what i'm trying to avoid... good luck w/that. since i have an iPod i'm fine w/AAC or MP3. i'm just trying to figure out which one might be better for me and then i'll use ABX or ABC/HR (?) to see what bitrate is best. it would be nice to have some recommendations for settings to try with AAC. i know that i'll try standard and extreme with LAME.

Try abx in a quite envoriment using these presets. If can't abx a few samples then go for the preset that saves space. If you are paranoid about the future then use some headroom like 'extreme' or 224.
If you can abx under some effort, ask yourself what are the chances of of being aware or annoyed at these differences during normal listening or using a portable in a busy setting.

Actually judging by the tests conducted here by Roberto (this one is the most recent) most people find iTunes @ 128kbit/s nearly perfect. However some can easily ABX it far beyond that. From what I can tell this has little to do with the equipment. It seems to be always (or nearly always) much easier to hear artifacts with headphones then with speakers and a quiet environment also seems to help but other than that differences in setup seem to make a fairly minute difference. So my best advice would be to test with any headphones you can get your hands on for now. I doubt it will make a great deal of difference. As far as bitrate I highly doubt that anything over 192 would be nessecary (although it is very possible). Personally 160 is good enough for me . . . even 128 iTunes AAC doesn't bother me very often, if at all.

thanks again musicman. that will definitely be helpful in narrowing down the bitrates i test. since i am concerned about the future i'll ABX 192 and 224 AAC.

any thoughts on LAME standard vs. extreme? would that roughly be the same as the AAC 192 vs. 224?

thanks for all of the really helpful replies.

My only problem with using tests to say things like "most people find iTunes @ 128kbit/s nearly perfect" is "most people" don't use as revealing phones as those mentioned by sbatth. I know I've said this before, but nearly every other variable is locked down, except this really important one, the headphones used.

Sbatth I think 224 iTunes/QT AAC works very well for ER4P/Ss and I suspect it will do at least as well for the E6/6is (and even more with the less detailed Shures). And I personally find the difference between 192 iTunes/QT AAC and 224 AAC to be greater than -aps and -apx, so I don't think they really align.

thanks blessingx. 224 iTunes AAC is working pretty well for me. i tried both 224 kbps AAC and LAME extreme w/my current cans and i couldn't notice the difference. i posted a question about testing here.

i said that encoding time didn't matter, but the 224 AAC avg'd about 7x while iTunes-LAME (3.90.3) did about 1.5x. that's a HUGE difference for me. i think i'm just going to test out the 192 kbps AAC vs. the 224 kbps AAC with ABX once i figure out how to get it working.

now the fun part... paying up for some nice headphones and reripping a lot of CDs.

thanks for the advice!

Nobody will ever complain that "it sounds too good". I use alt-preset insane just to avoid the hassle of a listening test, as well as the hassle of re-ripping my collection if I upgrade my hardware.

There was a time when I thought 160kbps sounded good, but then I bought a respectable sound system and re-ripped to 320kbps using Xing.

I then heard how inferior Xing was compared to Lame and re-ripped my whole collection to 320kbps stereo.

I then then discovered that Joint Stereo produces better results and re-ripped everything yet again to alt-preset insane. Many people here recommended "Standard", but I wanted to make sure I'd never have to do all of this again.

I'm done.

That's part of the dilemna when using lossy encoders since we "don't really know" if something will be improved upon (usually is), such is the case when LAME --alt-preset standard became --alt-preset standard -Z.

Alot of having to start-all-over-again is because things change (usually for the better). It's one reason why lossless is so appealing; regardless of the HDD space it consumes we need to think about the cost of a large capacity HDD versus the overwhelming time it takes to re-rip a whole collection. A lossy format with a quality setting that "may" end up being considered at an unrecommended quality setting in a year or several years down the road is always something I worry about.