Please excuse my ignorance of all things technical. I like to encode CDs with LAME 3.97 at 3 different qualities (for different purposes), the lowest one being 64K. I've been using Jacek Pazera's excellent (if buggy) Lame Front-End (LF-E). http://www.dhost.info/jack1024/lame_front_end_en/.

For a while I used LF-E's 64K preset. EncSpot tells me this produces "MPEG 2 Layer III" MP3s, at 64K and 24kHz. I thought, though, that if I force the encoder to output at 44kHz, instead of the default 24kHz, I'll somehow end up with better high-end response. It turns out, however, this new setup DOESN'T produce the result I hoped for. It does create MP3s designated as 44kHz, but they don't contain any frequencies beyond 11kHz, or so. Also, these are "MPEG 1 Layer III" files and EncSpot insists they're actually of WORSE quality than the 24kHz "MPEG 2 Layer III" files normally produced with the 64K preset.

Could someone briefly explain why LAME uses MPEG 2 Layer III for lower bitrate encoding, such as 64K? Why is this supposedly better than the usual MPEG 1 Layer III? Is there a perceptible difference between the results of these two types of encoding? Is there a way to encode frequencies beyond 11-12kHz at 64K?

I'd really appreciate your help. Thanks.

Short version: Just use the defaults, without any additional switches - the defaults are already optimized to produce optimal quality.

Medium version: If you dont know about the inner workings of MP3 and LAME, and you think about it logically, then it would be probable that LAME knows better than you about which settings to use. If you know about the inner workings of MP3 and LAME, then you KNOW that the defaults are already fine and as well dont need to fiddle with them.

Long version: Except for very exotic cases, there is no need for any obscure switches or presets. Just tell LAME that you want to encode at 64kbit CBR/ABR, and then leave the decision up to lame how to achieve that. It is already optimized and does not need any "tweaking". Increasing or messing with the Lowpass will NOT improve soundquality but instead worsen it. If increasing the lowpass would improve quality, there would be no reason to have any lowpass at all - so why do you think lame applies it - because it likes to worsen soundquality?

Thanks, Lyx. This is the first time I asked any sort of tech question on any forum. It's encouraging that there are folks like you out there who are willing to share their expertise for nothin'. I appreciate your patience.