Hey there clever audio forum,

I hope this isn't an obnoxious question to post. I did a quick bit of research on the wiki and forum but I didn't see anything too specific regarding actual recommendations for AAC bitrates etc.

Basically, I have 602 songs (16gb) in my iTunes library I encoded in ALAC with the hope that one day Apple might allow you to transcode on the fly to lower bitrates. This has not eventuated, so I've decided to cut my losses and just turn them into lossy AAC files that are a lot easier to handle and put on my iPhone with its limited space.

What I'm wondering is - if I want to maintain the best possible quality without squandering space, what settings should I use? My ears are okay but I only listen with fairly low-end stuff (Sony headphones, albeit the most expensive in-ear ones) and some bookshelf speakers + T-Amp. 128kbps is distinguishable for me (sometimes), but I'm not sure if 192kbps+ is. I really don't mind if the songs are in 320kbps or 160kbps, I just want an idea of where the commonly accepted "quality ceiling" is.

Is Quicktime still the recommended encoder, and will the latest (OS X) iTunes use it or need I go directly through the Quicktime player or command line to do my encoding? What sort of choice should I make in regards to a CBR or VBR?

I apologise for being so vague, but I'd just appreciate something along the lines of the whole "--alt-preset-standard" mantra I was taught to follow for for LAME. Would 192kbps VBR be a good way to go?

Thanks! Apologies if this is a question that has been asked before!

According to the last listening tests, iTunes AAC is similar to Lame mp3 so you can kinda judge the quality from those stand points. There really isn't any "--alt-preset standard" mantra when it comes to AAC. I would guess that 192kbps VBR would be similar to -V 2 (it is no longer called aps). I suggest that you sit down and conduct a blind ABX test. After all, you will be listening to your music with your ears on your equipment. No one can ever really tell you what bitrate to use, you have to judge for yourself as everyone's ears and equipment are different.

The iTunes/QuickTime AAC encoder is still pretty top notch so you can safely use that. When it comes to encoding audio, you should always choose VBR over CBR as VBR provides a more efficient encoding scheme. You can also use iTunes if you want as iTunes is just a front end for QuickTime. iTunes uses QuickTime to encode audio/video and to playback audio/video.

This question has been asked numerous times before, you can perform a search to pull up those results.