Digital music/MP3 encoding question...

[CanuckAmok]

Is it possible to take an MP3 file with a relatively low sample rate (i.e. 128Kbs) and re-process it through a program like Audacity at a higher sample rate (i.e. 192)? Is there a way to improve the sound via this method? I assume the raw data is all encoded in the file, and there for theoretically accessible.

The reason I ask is because I have been recording alot of vinyl into MP3 format, and I just realised I must have accidentally toggled "128Kbs" on Audacity, when I wanted 192 or even 256. I'd rather not go back and re-record everything, so can I just take the 128 MP3s and re-save them as 192? Will I notice a difference?

edit=typo (again)

[SHRED]

1. Nope

Sorry, but I have read, in my MP3 studies, that once it is recorded, that's it. Re-recording, at a higher rate, doesn't change the original quality to better quality.

[CanuckAmok]

2. Dammit!!

Wish I'd checked about thirty LPs ago!!

[LTR]

3. not a chance

It will sound no better than the 128kbps file.

[CanuckAmok]

4. Screw it!

I just tried saving the same .wav as a 128Kbs and aq 196Kbs file, and I can't tell the difference between the two, so screw it all! There probsbly is a difference, but even with headphones, I was hard-pressed to decide, and in a 'blind' test, in which I didn't know what bit rate I was listening to, I bet I wouldn't be able to tell.

I'm not going to re-record the files I've already done, but I'll record at 196 from now on.

Basically, after being run into my amp, or the mixing board at the local Co-op FM station where I do my show, I doubt if there's a significant advantage of 196 over 128. Line noise and the limitations of most peoples' FM receivers/listening environments will make it a moot point, I bet.

[LTR]

5. You shouldn't notice much difference

196 DOES sound much better (this is what I usually encode music at) but for most, 128 is fine.

And if it is for broadcast, I doubt anyone will notice. Most commercial radio stations keep music on hard drive using mp2 technology, at fairly low bitrates (most stations use Prophet automation software, which uses this horribly outdated format). Which is one of many reasons why commercial radio sounds so horrible these days.

[hunter]

7. 128 MP3 will do fine for FM broadcast.

I wouldn't sweat it. (Shhhhh, don't tell, you can get away with 96kbps mp3s for FM.)

How much music do you carry in your backpack?

[CanuckAmok]

9. Well...at the moment, I'm carrying:

About 700 LPs and full length CDs, and about 2500 loose songs.

Incidentally, with the exception of a few very rare and out of print single songs I scooped from Napster eons ago, everything I have is from my collection of vinyl and CD.

That's around 50 Gigs, soon to be dumped on my new portable hard-drive, which will hopefully arrive this week:

http://www.lacie.com/products/product.htm?id=10023

Mine's the 80G/5400rpm/8Mb buffer model!!

[ButterflyBlood]

6. I honestly can't tell the difference past 128

as an MP3. I can tell the difference if I burn it to a CD, but then only up to 192. so anything over 192 is a waste of space in my view. since I don't have a burner on my comp at school, I try to get everything in 128.

[IronLionZion]

8. mp3 blows

if you want to save space, try wma it's half the size with the same sound quality.

decompression rarely makes any difference so just leave it at 128

[CanuckAmok]

10. Thanks all for the advice. From now on, I'll go with 196...

...but everything so far will stay as I recorded it. I'm getting kind of sick of doing it!