I have a number of MP3 (and MP2) files which have unwanted audio at the start and end. I am also about to transfer my father’s collection of 78rpm records to MP3, and catching the exact start point is difficult, so I will start early and then edit.
I’ve been reading the help, especially the part on ‘Projects’, and suspect that editing is done at an analogue level. So saving back to MP3 would introduce a second compression and loss of quality.
Any suggestions?
Best I can recommend is to do the first save as uncompressed PCM or something like FLAC. That way there’s no loss when you do a second save.
Since you can’t edit and produce in Audacity MP3 without recompression, don’t. Use a purpose built MP3 editor such as MP3Split.
http://mp3splt.sourceforge.net/mp3splt_page/home.php
If you need extensive editing, filtering, and effects, you’re dead. Either Export in WAV or one of the other non-damaging, very high quality formats or Reeeeely high quality MP3. If you try to go back down to a similar compression and file sizes, you’ll destroy the show.
Never do production in MP3. Audacity is a destructive, digital editor. If you Save a Project and open it up again later, you will not recover old UNDO.
Never capture in MP3 at the start. Capture to a very high uncompressed format and archive that. Go down to MP3 for personal listening, but save The Real Thing for editing or further production. If you don’t, you’re going to run into exactly the same problems later and you’ll be in the garage looking for those records – if you still have them.
We are producing a paper on how to archive work, but you could do far worse than a series of WAV files.
Koz
I’ve been reading the help, especially the part on ‘Projects’, and suspect that editing is done at an analogue level. So saving back to MP3 would introduce a second compression and loss of quality.
You are correct that MP3 is lossy compression. It has to be decompressed for editing with a “regular” audio editor, so it goes through a 2nd lossy compression if you re-save as MP3. But, it’s NOT analog. (The “damage” occurs during compression. _De_compression does no further damage, and it gets decompressed when you play it anyway. )
Come-on, Koz… It’s not quite THAT bad! 
MP3s can sound VERY GOOD!!! A high-quality (high bitrate) MP3 made from a CD will often sound identical to the CD in blind listening tests. The MP3 format is far superior to 78’s or even more-modern vinyl LPs, cassettes, or anything analog (in terms of noise, distortion, frequency response, WOW & flutter, etc.).
MP3s can sound VERY GOOD!!!
I agree completely and I use MP3 all the time, but not under multiple compressions. Those can sound really strange.
There is a podcast where the company intro is clearly done from an MP3 or other compressed format (violating the MP3 production rule) and whereas it just sounds a little honky during the show (it doesn’t match the performance at all), by the time it goes through another compression, it’s in seriously bad cellphone territory. And all I did was cut it for my jogging iPod.
Koz
Many thanks for the four replies as I write this.
I’ve known that MP3 looses quality during compression, which is why I asked the question.
After a couple of hours Googleing without success, thanks that’s ideal for my requirements, as the splitting is done without decoding.
I’ve already transferred my CD collection to MP3 using VBR files and the quality is not up to listening to a CD with KEF speakers. But I’m now 68 and the ears are not as sharp as they were. However, the quality on my Bose head phones is acceptable.
For new transfers, I’ll use a non-compression format and save as MP3.
Can anyone suggest where I might find suggestions for suitable bit rates to save 78 records and 33.33 long play vinyls?
Thanks again.
For final export format (as already stated, not for re-editing), the “Standard” preset for MP3 export will give pretty good quality for music. The “Extreme” preset will give excellent quality (but with a larger file size). The “Insane” setting is probably over the top but will produce the best quality (least loss) possible for MP3 (even larger file size).
If your MP3 exports are just for listening on a portable device I’d suggest trying the “Standard” setting. If that is not good enough, go up to the Extreme setting.
Note that just because the 78’s may be old and crackly doe not mean that a lower quality MP3 setting will be good. Low quality MP3 settings can make the crackles sound “zingy” or “swishy” and stand out more than a higher quality MP3 version.
As long as you keep a high quality uncompressed backup version (WAV or FLAC format) you will be able to re-encode new MP3 versions from that if you want higher quality or smaller file size.
you may find this tutorial useful for your 78 transfers: http://manual.audacityteam.org/help/manual/man/recording_78rpm_records.html
WC