OK, I went playing... But I couldn't really tell a difference on the rig I was testing on...
PC -> SB Live -> Corda Analoguer (in bypass mode) -> Corda Headamp -> Clou Red -> HD600s
I suspect the SB Live is killing it here...
Anyway, I found the extreme setting to be a bit to large of file size for me. Busy music was almost pegged at 320. In the end and after some more goofing around I finally settled on these options:
lame --alt-preset standard --lowpass 21500 -v -b32 -B 320 -V 0 -q 0 --vbr-new --nssafejoint --athtype 2 --cwlimit 22.05
Thats a mouthful... On busy music (my test was Steve Vai's Bad Horsie) I ended up averaging about 254 kb.
I doubt setting the lowpass and cwlimit that high is gonna do much but those tweaks didn't seem to impact the file size all that much and I figure if it's there we may as well snag it!
The cwlimit tells the psycho acoustic simulator that the perception is as high as 44.1k can go (22.05khz) and setting the lowpass to 21500 makes the polyphase lowpass end at 22050 the uppermost theortical limit for frequency according to Nyquest (of course he was wrong, but thats a whole other debate). I figure if it's there why throw it out if it doesn't add too much to the file size?
The audio quality seems to not be impacted. I'll know more tomorrow after I encode a few albums and dump them to my PJB which is a MUCH better MP3 source the the SB Live!
I wish I could get my Tascam US-428 up and running, that thing kicks butt for audio though a bit overkill for most of us. (it's a small USB recording console soundcard and workstation capable of 24/48k). Unfortuatnly I am having a USB issue on my PC these days and no time to fix it.