I’ve used Audacity 3.7.3 to split a long WAV recording I made with a portable recorder into several tracks. It’s been a while since I used Audacity so I’ve forgotten if I can delete the WAV file and just keep the AUP3 file as a sort of original?
I see that the AUP3 file is 1,71GB and the WAV file 1,59GB, which leads me to think that Audacity copied the WAV data into the project file. Is this right?
I’d like to keep an (but only one) original of the recording and if the AUP3 file has the original sound data plus my track labels then that would be the better one to keep.
Philip,
Unless you are seriously short of space, keep both. The WAV file is standard and could be used as fallback if the AUP3 file gets damaged (it happens) or used in a different program than Audacity. It could also be used to begin again if you saved changes in Audacity and then were unhappy with them later. I think you will find the forum moderators would advise the same.
Mark B
AUP3 project files only work in Audacity. Depending on what you’re doing you may not need to make one at all. Once you are finished with your project you can delete it (if you’re 100% sure you’re done with whatever you’re going to do. )
(I rarely make project files.)
AUP3 files are often MUCH larger than the WAV files (depending on the complexity of what’s in the project file and the resolution of the WAV file.
AUP3 files are more “fragile” and more complicated than regular audio files so I always recommend making a WAV (or FLAC) file immediately after recording whether you make a project file or not. Of course if you’re working on something important and there’s no chance of “take-2” you should keep multiple back-ups as with any critical files.
Not exactly. But any “conversion” is lossless.
…As you may know, MP3 is a lossy format. It’s not always “terrible” but it shouldn’t be used as a temporary-working format. If you open an MP3 in Audacity (or any normal audio editor) it gets decompressed. If you export again as MP3 it goes through another generation of lossy compression and some “damage” accumulates. If you want MP3 (or other lossy format) you should compress ONCE as the last step.
@evilmrb Mark thank you very much. You make a very good point that the AUP3 file only works with Audacity. The WAV is clearly the more useful.
And I think I will take your advice Doug @DVDdoug and split the WAV into “track WAV” files to keep as track originals.
EDIT: Apologies, I forgot to ask a question. In the Export Audio box I can choose AIFF (Apple/SGI) as Format, which makes sense to me as I am on Macs. Or should I better pick WAV (Microsoft) because the original recording is a WAV file? It was recorded as 24-bit, 96khz with my Roland R-26.
Trying to find the answer myself, I saw this older thread where someone had also recorded in 24-bit/96 kHz and was recommended to select Other Compressed Files, select WAV and then Signed 24-bit PCM.
If I follow that logic, given the source WAV file in my case, will there be a difference in audio quality between selecting:
AIFF (Apple/SGI) + Signed 24-bit PCM
WAV (Microsoft) + Signed 24-bit PCM
Other Compressed Files – CAF (Apple Core Audio) + Signed 24-bit PCM
Other Compressed Files – WAV (Nist) + Signed 24-bit PCM
Thank you both for having helped me so quickly.
Cheers
Philip
They all contain the same uncompressed PCM data in different “containers”. Of course, that also means they can be converted between the different similar formats losslessly so you can change your mind at any time later.
FLAC (or Apple’s version ALAC) is lossless compression (almost half the file size) so it makes a good “archive” format even if you don’t want to (or can’t) use it as your everyday file.
24/96 is the “pro studio standard” and since your hardware supports it, you should use it. Audacity will convert it to 32-bit floating-point (at 96kHz). That’s easier and better for “processing” and the conversion to floating-point and back is lossless.
Floating-point also means that you can do things like boost the bass or mix and if that pushes the peaks over 0dB it won’t clip and everything will be OK as long as you reduce the level before exporting. (Amplify or Normalize can be used for that.)
When you’re all done, you MAY not want to keep the “high resolution” files. “CD quality” (16-bit, 44.1kHz) is generally better than human hearing so it’s usually good enough for anything. Uncompressed 24/96 WAV files will be about 3 times bigger than 16/44.1 (1.5 times bigger for 24-bits and and plus little more than 2 times bigger for 96kHz).
…Even a good quality MP3 can often sound identical to the high-resolution original in a proper blind listening test at about 1/5th the size of a CD quality file. It IS lossy and it’s throwing-away information to get the smaller file but it’s “smart” and it tries to throw-away little details that you can’t hear because they are masked (drowned out) by other sounds.
Ok I understand much better now, thank you Dough. I think you’re right that keeping the highest resolution files may in the end be an overkill.
I tested a few options and there’s not a huge difference, to my ears at least, between the original WAV recording and MP3, FLAC and M4A files.
Two things I’m curious about though are
if there’s any benefit in exporting to M4A at a sample rate of 96khz instead of 44,1khz, and
how the Quality (kbps) settings relate to the sample rate chosen?
For the first question, I know that the CD quality rate of 44,1khz translates (due to the sinus wave) to around 20khz and matches the human ear’s maximum hearing capacity. That seems to indicate that the resulting 48khz of a 96khz file will not contain any further useful information. What makes me unsure is that the frequency response of the microphones on my (old) R-26 apparently is 20Hz–40kHz. I certainly accept that we can’t hear above 20Khz but since there is virtually no difference in file size between an M4A file at 44,1 and one at 96khz, should it not just set the export dialog box to the latter?
On the second question, I see in Audacity’s manual that there’s a bug regarding the output kbps. Be that as it may, as I understand it the bitrate concerns how much data is transferred per time unit when a file is played (I could well be totally wrong here). So a higher rate should correspond to higher “resolution” or “detail” in the audio (but with a correspondingly larger file size). If that is right, will there be a greater benefit to select a higher kbps for a 44.1khz file than for a 96khz file?
Yes, you can delete the WAV file. The AUP3 file contains all the audio data and edits, including your track splits and labels. It acts as the full project file.
I don’t think so. M4A (and Mp3) are “smart” and they work by trying to throw-away sounds that you can’t hear anyway… Little details that are masked (drowned-out) by other sounds. At the same bitrate they should both turn-out about the same quality. Of course if you go “too far” and go down to 8kHz or something, the sound will be “damaged” before it’s compressed to M4A.
There is no direct relationship. I’m not really an expert on M4A but there are settings where you choose the “quality” and the encoder chooses the bitrate moment-to-moment depending on how hard it is to compress. At 96kHz you MIGHT get a higher bitrate with the same quality setting. (I’m not sure if you can use the “quality” setting in the custom FFmpeg configurations but there are other encoders that can do it.)
Almost… But before it’s played it’s decompressed back to regular PCM at the bit-depth that matches your DAC.
Right. At lower bitrates more information has to be thrown-away. BUT, a 192kpbs file can sometimes sound identical to the uncompressed original and in that case we can’t say 256kbps is “better”.
kbps is kilobits per second. There are 8 bits in a byte so you can divide by 8 to get kilobytes per second, and from that and the playing time you can calculate file size (ignoring any embedded artwork which adds to the file size without affecting the bitrate).
…We usually don’t talk about the bitrate for uncompressed files but It’s easy to calculate: A CD quality WAV file is 16-bits x 44.1k samples-per-second x 2 channels = 1411kbps.
Except as I mentioned, there are quite a few posts here that say, “I can’t open my AUP3 file”.
the original recording (as FLAC - saves ~50% of the WAV)
the AUP3 project (zipped - saves quite some diskspace)
the exported label track(s)
intermediate step FLAC(s) after eg. normalization, cropping and before any edits
the final exported show (as FLAC) before export multiple (ie. chopping into individual tracks)
The idea is that with (a) FLAC that match(es) the audio track(s) in AUP3 + the label tracks I can recreate the project instantly.
And with the original recording I can start from scratch if I messed up.
If I run out of diskspace I first delete 2), then 4), 5)
)