importing and then exporting mp3 - does it affects sound?

[UniversalFlyer]

Hi,

If I move mp3 file to arrangement, set track volume to 0.0db and then export will this affect the sound?
What about normalize function, khz, peaks?

For example if I want just extend the track what options do I need to choose to keep original part not affected?

[dsu]

MP3 files use a lossy compression algorithm. This means that when you open it up, edit it save it as a MP3 and them open it up, edit it and save it as an MP3 it losses some of the original information. The solution for production is to convert to a wave or aiff format before working with it. Then the retain the accuracy of the original MP3 file.

When the project is finished and converted to MP3 the clip will not have lost very much accuracy.

[Tarekith]

Yes, everytime you convert to MP3 you lose some sound quality, it doesnt matter if you convert to a wav first. Everytime you drag an MP3 into Live, it's creating a wav for you already and storing it in the decoding cache in fact. It's a last resort thing in my book, if you REALLY have to do it, well then go for it. But there's definitely going to be some quality lose anytime you keep converting to a lossy format like MP3. Start with the wav in the first place if you can.

[UniversalFlyer]

Thanks guys. Maybe I was not very clear.
I want to prepare mp3 tracks for mixing by adding some extra loops at the beginning and at the end.

For example:

<extra loop><--------------original mp3 track-------------><extra loop>

Is it affects original mp3 track? Approximately, how much when doing it with 320 kbps quality? I understood that exported wav file will be converted to mp3 and sound will be compressed.

The main thing is that sound will be compressed two times (original mp3 compression + my export). It is the issue with most of mixes created with Ableton.

Maybe the same frequencies are affecting when compressing in this way wav--->mp3 320kbps--->wav--->mp3 320kbps, isn't it? Is there any other way to extend the track and save the quality?

[Tarekith]

You were perfectly clear, what you want to do can severely affect the overall sound quality, even with 320kbps MP3's. Maybe that trade off is worth it for you and you don't hear a big difference. But there are people out there who can, and it can be really obvious on a louder sound system too. Your call if the loss of quality is worth it for you or not.

Like I said, you're better off just starting with an original wav version if you can, then add your loops, export and convert to 320kbps MP3 if you really have to.

[UniversalFlyer]

Thanks for good explanation. I think best option for prepared track is .wav version

[102455]

Have a look (and listen) here http://scruss.com/blog/2012/02/21/gener ... -encoding/

In my opinion, if you do it just the once (320->WAV->320) then the difference will be imperceptible.

Maybe you might notice something if you played the original back-to-back and swapped between them, but even then you'd have to have a damn good playback system and a good pair of ears. Of course yes it's better to start from a WAV....but if you can't - just do it once.

FYI you could do a phase cancellation test if you wanted to hear/see exactly what was removed from the re-encoded file. Take the original and a copy that's been re-encoded (but not modified in any other way) and subtract one from the other (invert the phase of one track). The result is the difference.

[muthafunka]

If you really want to keep it as legit and small as poss. make sure to have no warping enabled and simply edit/paste and export to wav/aiff. If you want to avoid an extra conversion but still get a bit of space convert to flac....if you're djing in Live then the flac or mp3 thing is kind of a false economy though as it converts mp3/flac to wav in its cache when you add it to a set anyway. Unless you're doing hundreds of tracks the overall storage impact will probably be negligible.