large files and converting as mp3

[Mal]

Hi, Hope this is the right section of the forum for this.

I just wanted a bit of advice on saving large files and converting as mp3.

If I save the files as aup and its associating folder, it's obviously a much larger file size than saving as mp3. So I just wanted to know if saving a long audio piece recorded with audacity as an mp3 instead, and then editing it later and saving it again as mp3 would effect the quality of the originally saved mp3. Hope that makes sense.

I personally can't tell any difference when a 320 bit rate mp3 is cut/edited and saved again as mp3.

Which ever method I wouldn't stray away from the full 320 bit rate.

TIA

Cheers

[Irish]

So I just wanted to know if saving a long audio piece recorded with audacity as an mp3 instead, and then editing it later and saving it again as mp3 would effect the quality of the originally saved mp3.

Yes.

Every time you export from Audacity as MP3, you put the audio through the compression process, which degrades the quality.
(try it yourself: export something from Audacity as MP3, import it again, do a small edit and export as MP3. See how many times you can repeat this before you end up with rubbish).

Export as WAV. This produces an exact copy of the audio that you can re-import and edit as often as you like with no loss in quality.

When you have the final version that you want to send to a friend, or listen on your iPod, then export as MP3 for that.

PO'L

[Mal]

Cheers for that, Irish.

I'd only ever saved twice as mp3, plus only on the odd occasion and with this sound card they always sounded bright and descent.

Using wav will be more convenient as it leaves just one file, does it also create a smaller file size than saving as aup and its associating folder?

I'm so glad I asked now.

Thank you.

[Mal]

Just to answer my own question, a small section of audio I recorded last night was saved as wav, and was 630MB in size.

I also saved the original audacity files, just to compare, which were 1.25GB

Thanks for the help, Irish, much appreciated.

[Mal]

I've now started saving as WAV, but I'm a little concerned at reading the following from the audacity help files:

"People working with multichannel audio at very high quality settings, or with very long recordings, should note that the maximum size of a wav file is 2GB"

Does anyone know the reason why WAV files are supposedly restricted to 2GB? I then read a little on wiki that mentions 4GB.

I have a saved wav that is 7,125,875 KB, will that still be any good? Used default settings in audacity sample rate of 44100 Hz and WAV 16 bit PMC.

I'm confused.

TIA

[stevethefiddle]

The WAV format specifies a maximum file size of 4GB.
Quite a lot of older Windows (XP and earlier) computers had a file size limit of 2GB.

I'm surprised that you managed to save a WAV file over 7GB. If you have a modern 64 bit computer it is perhaps possible to go beyond 4GB, or perhaps Audacity is now supporting a modern variant of the WAV format that allows file sizes greater than 4GB - I'm not sure, I never use files anywhere near as big as that.

You will probably find that some media players will choke on such a big WAV file, but if Audacity produced it, then there is a veru good chance that Audacity will still be able to open it. Very large files can be quite problematic in lots of ways, so I would suggest that you Import the file back into Audacity and Export it in a number of smaller chunks (files up to 1 GB are much easier to handle and files up to 700MB can be burned to CD, which is a cheap and convenient form of backup). You can export part of a file by selecting the section to export, then use "Export Selection".

[Mal]

Thanks for that steve

Yes I have 64 bit vista, Plenty of ram too.

The only reason I have such large files is because I occasionally leave audacity running overnight recording. That leaves me with about 16GB of aup/au files *gulp....so I tried what was suggested here and saving as WAV to lower the file sizes, then ultimately they are edited and turned into 320k bit rate mp3.

I have opened that 7GB file ok in audacity, that's why I was confused, thinking maybe it effects the quality or misses parts out. So far I haven't had chance to edit it and see if it's ok, but will report back if all goes well.

Cheers