Sample rate & file size issues

[Brendo613]

First, I'd just like to say how comfortable with Audacity I am at this point. I've been a regular user of it since December 2007, to record live music and to make multitracked, studio-polished products from. I write asking two things.

I am only able to record with the sample rate set at 44100, and the only way I can change the HUGE file size generated is by altering the bit depth. I would be very grateful were I to be able to record at 22050 for a smaller file size, but need some help getting that to work. Even at 16 bit, the size is too big for my liking.

Secondly, is there any way to convert previously recorded audio to a smaller file size? I have 103 GB of audio data recorded since December 2007, and - with the exception of 12-07's and 1-08's recordings which were done at 32-bit depth - all audio has been recorded at 44100 khz, 16 bit.

Please, any help on configuring my copy of Audacity - 1.3.3 - to record at a smaller sample rate, and any help on the possibility of converting old files is greatly appreciated.

[Brendo613]

Help please!

[richardash1981]

If you really want to reduce the sample rate, then simply change the Project Rate dropdown at the bottom left to the desired rate before you start recording. If you want to reduce and existing recording, then you can open it, change the project rate, select the whole track and use Project > Mix and Render to convert the track to the new project rate.

Note that if you resample to 22050 Hz then you will remove all audio above 10kHz, which will tend to make the recordings sound muffled. A better option might be to export the finished 16-bit 44100Hz recordings to FLAC, which would normally achieve a lossless compression ratio of 2:1 or better, so there would be no loss in quality.

[steve]

FLAC would be the best option as it preserves 100% sound quality while reducing the file size to around 50%.

If you need even more space savings, you can use MP3 or Ogg formats. With these you can achieve space savings of around 80% but there will be some loss in sound quality (it will still sound better than a 22kHz recording though).

External hard drives are pretty good for backup storage (not infallible though - they can sometimes break) and are available in very large sizes at fairly low prices.

[waxcylinder]

External hard drives are pretty good for backup storage (not infallible though - they can sometimes break) and are available in very large sizes at fairly low prices.

I can certainly confirm this - my 1TB RAID external disk failed after just 3 months recently (the supplier/manufacturer did replace it - but it took over two weeks) - it's why I back up to two external USB discs at least ...

WC

[Brendo613]

Is there a way to have Audacity record in a different format, or do I have to convert all existing recordings to FLAC, etc. after they're recorded in wav format?

[steve]

Audacity always records uncompressed audio data (at whatever sample rate/bit depth you have selected).

When you "Export" from Audacity, this creates an audio file ("Audacity Projects" are NOT audio files) and can be WAV, MP3 (if Lame is installed), Ogg, Flac, Aiff and in recent version if ffmpeg is installed, a selection of other formats.

There are various third part utilities that can be used for changing files from one format to another outside of Audacity.

MP3 and Ogg formats are "lossy" (there is a loss of sound quality) but provide high compression ratios. Flac will only give around 2:1 compression but is "lossless" (no loss of sound quality).

[Brendo613]

I guess my best bet is to record, mix later to whatever codec medium (I'll probably do a midrange VBR mp3), then import the file later for editing. I can even import the label file, too! Cool feature I didn't know about. Only issue is that, the more compressed I make the file, the longer Audacity takes to import it :- I suppose, problem solved for now. Just gotta go compress, oh, more than a year's worth of jams ... this'll be ... exactly how it will be (to say the least)