Can I do minor edits without re-encoding lossy files?

Hi all! This is my first post here but I’ve been a looong time user of audacity. Before 1.0 if I remember correctly. I’m not an audio engineer or anything, i just use it to random tasks. I do minor edits to my mp3 collection particularly when making mixes for my buddies. I’ve also used it to make some sound effects for the open source game Battle for Wesnoth. I’ve also used it to record the opening credits song off of my Dead Man DVD which wasn’t included in the Dead Man soundtrack. (It’s the only song in the whole movie that can stand on its own without the film so I found it ridiculous that it was the only song not on the CD, but now I’m really digressing…) Anywho, before I ask my question I wanted to thank you all for making this excellent piece of software that has been invaluable to me, from when I first discovered it as a windows user to right now on my Ubuntu system. Audacity may very well be the first piece of open source software I used and it has shown me the light!

Now on to my query… I’m making a mix CD for a pal of mine. One mp3 I want to add is a live encore track that has a huge intro of the audience cheering to get the band to come back on. I’ve very easily trimmed most all of that out and put a little fade in before the song starts. Normally I would just save this file as a wav or flac since its gonna get turned into an audio CD and then deleted. But this time I would also like to save a trimmed copy in my music library so I don’t have to listen to the roaring crowd for a minute and a half before the song starts. I don’t however want to re-encode the mp3 and lose precious audio data. Is it possible to save this track as an mp3 keeping the current bitrate etc without re-encoding the file? I reckon this is possible if I just trim the cheering out, but the fade I added may make it impossible. I’d be willing to do without the fade if need be, but if I could save the file and only re-encode the fade (the part that changed from the original track) keeping the rest of the bits in tact, I would be ecstatic. Are either of these techniques possible?

Thanks in advance,

Audacity doesn’t edit MP3. It converts to full quality uncompressed and edits that. If you go back to MP3, you will have gone through the compression process twice, once to get out and once to get back in.