history of effects

[monus4444]

Can we know history of effects applied to mp3 file after saving and closing it and when we again open it fresh.

[SteveG_AudioMasters_ · Accepted solution]

No, not at all. For a start, Audition doesn't open MP3 files as such, it decodes them to wav files. What you do to them then is only stored as a sequence of temporary Audition files that you can step back though, and the moment you save the file, that information is deleted - otherwise you'd end up with a drive entirely full of useless temp files in no time.

And then, after you've done whatever you are going to, you're going to save it as an MP3 again, so it's going to get re-encoded. No information transfers with that either, as there's no provision within the metadata to store anything like that at all. And there's a reason for that...

And that is because MP3 files are distribution files intended for finished work only - not production purposes. Any processing that's happened to it is essentially irrelevant.

Also you should note that every time you open, alter and resave an MP3 file in Audition, it loses quality because of the decode-re-encode process - often quite noticeably if it started out as 128k. It's fine to open one and play it, and then close it again without altering it, but that's all.

[monus4444]

thank you for your answer, apart from opening and editing mutiple times, does noise removal also decreases the quality of sound.

[SteveG_AudioMasters_]

It can do unless you do it very carefully, and in multiple passes at different FFT sizes, and hardly take any off at each pass. In theory NR looks simple; in practice it's one of the hardest things to get right.

[monus4444]

thank you but what is meaning of multiple passes at different FFT sizes.

[SteveG_AudioMasters_]

This applies to the Process NR effect, not the Adaptive one. The adaptive one is only really any use for situations where the background noise varies a lot, and it has more artifacts anyway, so really, it doesn't work so well.

The basic rule is to use multiple passes (eg, do it several times), at different FFT settings, and don't take too much noise off in a single pass. Personally I start with a high FFT setting, but I wouldn't take more than about 6dB of noise off (typically) and this avoids the build-up of artifacts. Then do another pass, similarly, at a mid range setting, and the last one at a low setting. The FFT size setting is in the Advanced section of the NR, and if you change it, you will have to define a new noise print. So you may well end up doing this three times (typically).

The important bit at every stage is to listen carefully to what's happening, and always err on the side of caution with it, especially whilst learning what it's capable of.There is no 'one size fits all' about this, and you have to practice. to get it right, as it's very easy to overdo it.

[monus]

thank you very much