"True" AAC VBR

[mereanUs]

What settings should I use to get this? What I mean is that I want the best quality for the size of the file. I only want as large a file as the quality of the song demands. So, what do you think I should I set the bitrate at?

[Mike1]

What settings should I use to get this? What I mean is that I want the best quality for the size of the file. I only want as large a file as the quality of the song demands. So, what do you think I should I set the bitrate at?

You can't do it purely on a quality basis with Apple's AAC encoder; you have to set a nominal bitrate.

FWIW, the default setting for Nero's AAC encoder for Windows is -q 0.5. That, apparently, will give "about 160-170kbps on average". But that is an average ...

You just have to make a trade-off between what quality you're prepared to accept and what space you have.

[jolinwarren]

So, what do you think I should I set the bitrate at?

I would recommend 160 kbps as the bitrate with the maximum quality setting and VBR. See my related post on this topic.

I settled on 160 kbps VBR AAC after reading a detailed article on encoding classical music by Kirk McElhearn. After reading the article, I emailed Kirk with some questions regarding how he chose his encoding settings. He explained as follows:

I decided on 160 AAC after doing blind listening tests. I could probably get by with 128, but I figured that if it is the default, then I should go one notch better. I really can't tell the difference between 160 and lossless. For some recordings, 128 is a bit too low - the solo harpsichord, especially, is one place where the difference stands out.

That was good enough reason for me to use 160 kbps AAC without doing my own tests. Since Kirk's initial tests, the VBR option was added to AAC encoding. Some discussions on the internet (can't remember which ones now) indicated that 128+VBR was as good as 160 without VBR. As disk space continues to get cheaper, I've decided to play it safe and stick with 160 and also enable VBR to get a bit of extra quality.

Hope that helps.