What is the biggest difference between converting from CDA to MP3 (192kbit) an then from MP3 (192kbit) to MP3 (128kbit) than converting directly from CDA to MP3 (128kbit)?

Am I loosing too much quality? I've got some songs in 192kbit format and I'd like to convert them to 128kbit but I'm not sure whether I'm going to loose more quality this way than doing this directly form the cd.

Please do not answer with just "do it directly" but explain a bit the pros and cons. Thank you fellows.

If you do it CDA-> MP3 128K:
- u will have much better quality.
- u spend a little less time encoding, because there is no second decode stage.
From 192-128k
- the quality will not be optimal, trebles get the "metallic clang sound" and is not as clear
- you spend more time re-converting
- u still have a higher quality MP3 residing on your hard disk for other purposes if you need it

mp3 compression is a so called "loss" compression, i.e compression is accomplished removing some informations from audio file.

if you compress in this way an already compressed file, then you remove other informations. So on every compression step you loss sound quality.

I suggest to leave these files at 192kbit, that is a better quality of 128kbit (yes, file are larger, but quality is better)

The problem with recompression (theoretically), is that not only is MP3 "lossy", but it can also introduce artifacts of it's own.

Recompression then tries to represent the audio and the artifacts, so wastes bits on the inaccuracies of the first compression.

Practically, generational loss seems to be lower than would be expected.

There are other two things to consider.

1) The quality of the source file. A bad file can only become wronger after conversion.
2) The individual capacity to hear these differencies. Not all are able to distinguish a 192kbit file from a 128kbit (me for example ).

@displeisisfactap
Try to do some conversions.
If these differences are not so heavily udible then you can reduce file dimensions converting from 192 to 128.

Hey, thank you. I got it clear now. I'll ckeck both ways and compare results (I don't think I'll find a difference, though). But now I know I should always use the source when possible (don't know much about encoding). Thanks!

You're welcome