Although not conclusive, here's a link that shows an attempt at measuring for objective results between different encoder engines:

http://www.ars-technica.com/wankerdesk/1q00/mp3/mp3-1.html

(no, I didn't make the address up, it is truly "ars-technica" and "wankerdesk"!).

Anyway, I was equally curious what MP3 encoding at different rates would do so I did a little experiment:

First ripped 3 different pieces of music as WAV's and then converted each to MP3 at resp. 192, 128, and 96k. These MP3 files I converted back to WAV and burned the whole lot on to a CDR (12 tracks total; 1 x WAV, 1 x 196k; 1 x 128k; 1 x 96k for each piece of music).

This way I could listen for myself on my own (pretty decent) stereo system, using the original CDs I ripped from as a benchmark.

I know you can blow wholes in this procedure as a means of assessing MP3 compression ratios, but the results were pretty interesting none-the-less and showed up much more differences than using my PC sound card (cheap generic) run through the stereo system.

The differences are very noticable in my opinion, but I decided that 128k will be good enough for me for the time being (I'm also thinking of using same MP3s in diddy solid state portable, so size does matter).

Whatever is good enough is a personal choice anyway, it's not someone can tell you; what I may find a big difference you may find barely noticeable or important and vice-versa. Try it out for yourself, perhaps method described above gives a little bit more insight.

On the issue of ripping; I've found that using my samsung 40x DVD-Rom gives worse results than using the Philips CD burner to rip from.

Cas