Quality of resultant mp3 after minimum edit?

Dear forum people,

The situation is: from what's recorded, I create in Sonar an mp3 using LAME at the best possible mp3 specs.

The project is discarded, not saved, nor wave files.

Then, if I wish to do a minimum edit, like cut noise at the start or end, or amplify the whole thing up, say 3db louder, but add no effects, or any other such things.

Then if I save again as MP3, with those minimal changes, at same mp3 quality as originally done, would the new mp3 quality, in any way change, as compared to the original mp3?

Same issue, put another way, if I load an mp3 into Sonar, which puts it in a track as wave, if I don't do anything, but save that wave as an mp3, but with a different name, same mp3 specs, would the original and the new name mp3 be identical, as far as audio quality is concerned?

Meaning something like: wave to mp3 we loose quality, but what about mp3 to wave and then back to mp3, do we end with the original mp3 quality, or is there any loss somewhere? (using always same mp3 quality, and best wave quality possible, in the same system; and even the original mp3 created in same system).

Thanks for any replies.

Hi Slugbaby,

And thanks for your reply...What you say sounds like a big loss, and am curious to know some more about this..It's not awful important, though, but so I get some confidence on things I do or want to do once in a while.

I do notice, though that I hear the original mp3 via the MS-Media Player, and I hear the wave from it at Sonar and they sound identical, and offhand, the wave seems to sound even better in Sonar.

And I do put it back as an mp3, and I can't note any difference; but am not saying there isn't any, though.

My logic is kind of like if Wave is a bigger box and Mp3 a smaller one...Big box fits Little box without chopping any thing, and can render Little box back intact..

But that's just a thought, though...The other way around, of course we all know is not true.

There's probably some "depends on" things..Maybe someone has more on this, and would help us clear a few things.

Thanks again!

Thanks! I appreciate your comments. I found this same question elsewhere and yes, there's a lot of depends. You are right on that there are losses, though, from what I read.

bitflipper

Then if I save again as MP3, with those minimal changes, at same mp3 quality as originally done, would the new mp3 quality, in any way change, as compared to the original mp3?

Yes, the quality will definitely be lowered. Whether it's lowered enough that you'd notice or care, that can only be answered by trying it.

You do not lose anything (well, almost nothing) by converting from MP3 to wave - but what had been lost when it was previously converted to MP3 is gone forever and you won't get it back. Then, when you subsequently re-encode to MP3, you will lose some additional information. However, it's quite possible the degradation will be unnoticeable.

Hi Bitflipper again,

I tend to believe that when an mp3 is played back it should play to its full self-contained capability, otherwise it wouldn't make sense that anmp3 has more data that can be played.

Therefore, it seems to me that converting it to wave, should loose no data, unless the converter would limit it, but it shouldn't be due to a limitation of the wav format.

When playing an mp3, the player, and the sound card, and other things could drop data, though?

If I am not clear on this, please correct me.

Thanks again.