I couldn't find a review, comparison or guide for CDEx settings when using the Lame encoder so I did some playing around today. Before today I just set CDEx to a bitrate of 192 and forgot about it. Now I'll be going back and re-ripping a bunch of disks that I actually like to hear, because I expect my MP3s will be around longer than a bunch of my CDs and they're a whole lot handier.
Since my desktop speakers suck I tested with my daughter's Sennheiser HD437 headphones (a good deal for the sound), my old Sony MDR-AV5s (don't look, they don't exist anymore), and then my Sony inner-earphones (MDR-EX51LP). First conclusion: the Sony in-earphones aren't as good as I thought; fine for the laptop when EQed, not so great when compared with decent headphones. Though it doesn't affect the results here, the old Sony set was the best sounding and the Sennheisers (surprisingly) ran a hotter signal.
The computer has a garden variety sound card, the CD drive is actually a generic CD-RW/DVD-R, and I played everything through WinAmp with a flat EQ.
I used the Breeder's old Safari EP for the test -- Do You Love Me Now? and Safari were the tracks I picked. This EP was originally recorded and engineered on tape and later encoded for the CD, and for this purpose that means there's more to hear; on a good system you can tell where channels and effects punch in and out, and background sounds from the studio aren't edited out. When you can hear Kim Deal lick her lips between notes, that's a good thing.
These will be my settings until I find or hear something new...
Thread Priority: Above Normal.
It doesn't make a difference to the sound, but does make ripping go faster.
Version: MPEG I.
Set it to anything else and the bitrate maxes out at 160.
Bitrate Min/Max: 192/320.
Set to VBR and you get a range instead of just one bitrate setting. I first tried 160/320 and the sound was noticeably warmer and nuances were better defined at 192. To me, it was worth whatever size it added. I later tried 256/320 and the difference wasn't as impressive. Though the actual bitrate varies, Winamp reports a single value which I would guess is the average and the tracks I tried reported 238 and 268 at 192/320 (for an extra 1Mb per file), 285 and 286 at 256/320 (.5 Mb difference). So the reported bitrates went up by 47 and 18 respectively, and while the sound was closest to the original CD, I didn't hear anything new and the difference didn't justify the extra storage. 192/320 is where I'll live.
Definitely preserve the original channels. The alternatives save space in ways that seem to me like saying "sometimes mono is just as good."
Quality: Very high (q=0).
At min/max bitrates of 160/320 and a Quality setting of High (q=2) I saved about 200k per song vs. Very High, but there's a slight choppiness that comes off like stair-stepping in the wave. At 256/320 the files sizes were identical so this seems to be a relative setting that may not come into play at high bitrates. If it does make a difference, I'll take the setting that isn't liable to sound choppy at lower bitrates.
On-the-fly MP3 Recording: Disabled.
This copies the track to the hard drive before running the final conversion. When enabled you get occasional stutters in the output, and I suspect it's worse with badly scratched CDs since you're relying on the drive mechanism to stay in synch with the codec that much more.
VBR Method: VBR-MTRH.
Variable bitrates mean that extended silence takes less to store than a busy section. Rather than rip everything at 256 or 320, this sounds like a good idea to me. VBR-HTRH was indistinguishable to me from VBR-New, and produced the same file size. It's a hybrid between VBR-Old and VBR-New, so why not.
VBR Quality: VBR 0
Lower is better. One of the few things I didn't bother to test changes with.
With these settings and the Sony headphones I could hear as much in the recording as I'd expect from a good set of monitors -- mistakes, breaths, the natural reverb of the room on the vocals, gating on the drum mics -- that's as much information as I expect from an inherently lossy format like MP3, and better than I expected.
Something I didn't expect happened when I let the CD run from Safari (track 3) on to track 4. I've long complained that when listening to a lousy cd player -- and this one's obviously designed for data, not music -- everything seems to stutter, like the sound really is delivered in digital chunks one after-an-other rather than as a smooth wave. So I ripped track 4 to the above "best-of-all-worlds" setting too, and the stutter disappeared. Whether the stutter was caused by a scratch or a lousy mechanism I don't much care, reading from a reliable medium solved it. If all it means is that you're better off ripping to a drive than playing cds through a computer, then hey, I learned two new things today.