Importing Audacity .wav files - "Unrecognised or unsupported WAV file header in

[TimArends]

Hello,

Since I had a recording that was already created in audacity, I worked with it to prepare it for VinylStudio, including editing out the extraneous bits, converting it to mono (since  the original recording was mono) and combining side 1 and 2 of the album into a single file and saved as a 44Khz WAV. Now, when I attempt to import it into VinylStudio for denoising and splitting into tracks, VinylStudio gives the message:

"Unrecognised or unsupported WAV file header in file"

and it refuses to import it.

This is odd, since every other program I attempt to open it in, including QuickTime Pro, iTunes and Audacity itself, have no problem opening it.

Can VinylStudio not work with Audacity .wav files?

[Paul Sanders (AlpineSoft)]

Hi,

It's probably because it's mono.  VinylStudio cannot work with mono files.  If you save it as a stereo file you should be OK.  It pays to keep your mono recordings in a stereo format in fact because the declicker works better.  Clicks are often much more prominent in one channel than the other and converting to mono effectively halves their size, which makes them harder for the click scanner to detect.

[TimArends]

Thanks for the reply.

If an original album is mono, I like saving it as mono, since the resulting MP3 or AAC file will be that much smaller on my iPod or in iTunes.

Does that mean if I want mono I must bring it back into Audacity after declicking? Or can VinylStudio save as mono as a final step?

I mainly bought VinylStudio for its denoising capabilities anyway, but it would be nice to be able to do the final track splitting in VinylStudio, but not if I will have to "monotize" a dozen separate files afterwards.

[Paul Sanders (AlpineSoft)]

Hi,

No, sorry, VinylStudio cannot currently generate mono files.  But you might find that the resulting MP3 / AAC files are not much larger anyway.  I would experiment before going to a lot of unnecessary work (and I'd be interested to know how much difference it makes).

[TimArends]

Huge difference. The file size of one album with two tracks in .WAV format is 374 MB. After converting to mono and re-saving as a .WAV with the same settings it is now only 187 MB, exactly half the former size.

[Paul Sanders (AlpineSoft)]

Ah yes, for WAV that will be true because it is an uncompressed format, but for the compressed formats typically used when saving tracks I think you will find the difference is a lot smaller, and mixing down to mono as a final step probably doesn't save you much space on your iPod.  That's what I was getting at.

As for your master recordings, it's worth keeping them kicking around (if you have enough space on your hard disk) in case you want to make a change and save your tracks again for some reason.  We will be supporting FLAC format (and Apple Lossless) soon, which will cut these files down considerably while being lossless.  Again, my expectation is that mono files will compress better than stereo files, but probably not markedly so for these formats.

[TimArends]

Hi,

I just saved two versions of a complete album as AAC (iTunes doing the conversion), one of them being "stereo" (really a mono album digitized as stereo) and the other being converted to mono by Audacity (after denoising and declicking in VS). The "stereo" version as AAC is 66.9 MB and the "mono" version is 33.7, so even in AAC format the space savings is about half. So it makes sense to save mono albums as mono if you want to save space on your iPod.

I can understand that VS can denoise more easily with stereo files, which makes sense, as it no doubt compares one track to the other in determining what is music and what is noise, but it would be nice if it had a feature to "monotize" the file after denoising and before splitting. Perhaps in a future version.

[Paul Sanders (AlpineSoft)]

Hi Tim,

Yes, I agree, it would.  We will put it on the list.  If and when we get around to doing it (and I hope we do), you will be able to save your tracks again, so all of the work your are currently doing will not be wasted.

Thanks very much for providing the information.

[Paul Sanders (AlpineSoft)]

I have a bit of additional information on Mono vs Stereo file sizes.  When saving as MP3, the difference doesn't seem to be so marked.  I observed an average 20% increase only.  This was saving at highest quality VBR.  YMMV, as they say in netspeak.

[saronian]

Hi,

I just saved two versions of a complete album as AAC (iTunes doing the conversion), one of them being "stereo" (really a mono album digitized as stereo) and the other being converted to mono by Audacity (after denoising and declicking in VS). The "stereo" version as AAC is 66.9 MB and the "mono" version is 33.7, so even in AAC format the space savings is about half. So it makes sense to save mono albums as mono if you want to save space on your iPod.

If the compression, AAC or MP3, is using the "Joint Stereo" setting, then the stereo version of mono material will result in files that are almost equal in size. I tunes does not use Joint Stereo for AAC but it can be activated for MP3.

[Paul Sanders (AlpineSoft)]

OK, thanks.  I think in fact both encoders switch between Joint and Mide/Side stereo on a frame-by-frame basis, depending on which offers the best compression for that frame - we don't use iTunes to encode tracks.

But I have realised what the problem is with AAC.  To get good compression of mono material, you need to enable VBR (Variable Bit Rate) encoding, which you can do in the AAC options dialog.  This cuts file size dramatically when saving mono material, even when saving as a stereo file.  The default encoder settings for AAC are 128 kbps ABR (Average Bit Rate), which is why you see no improvement with mono material as the bitrate is fixed at 128 kpbs.  The VBR setting works well with stereo material too, so you might as well leave it on for everything.

The next major version of VinylStudio will in fact offer a 'mix down to mono' function when saving tracks.  It will also support more file formats (not before time!), including AIFF and FLAC.  We will be looking for beta testers soon guys, so let me know if this interests you.

[saronian]

Very good to know! I like VBR when compressing for the iPhone (only 8GB).

[Paul Sanders (AlpineSoft)]

Yes, VBR offers the most 'bang for the buck'.  We would make it the default but most people seem to use 128kbps ABR so I'm not sure if that's the right thing to do.  I doubt there are any player-compatibility issues though.

What quality setting do you use when saving tracks for your iPod?  My own tests show that the default setting of 64 (i.e. bang in the middle) generates roughly 128 kbps files for stereo and 60-70 kbps for mono, but I believe that a VBR file averaging out at 128 kbps will offer slightly better qualiity than a 128 kbps ABR file because the encoder has more latitude to tune its encoding parameters to suit the complexity of the music when encoding to VBR.

[saronian]

I use "iTunes-LAME" with the setting "--alt-preset extreme" which usually averages between 160-200kbps. I listen to the iPhone with a line out adapter feeding a small "The Hornet" amp and Sennheiser HD595 headphones.

This setup sounds so good that lossless files are the best, but that's going to have to wait for the new iPhone with hopefully 64GB.

However I just heard a demo of the Peachtree Audio Nova and it's ESS Sabre DAC made even streaming Pandora sound good. So next purchase will be some type of external DAC.

[Paul Sanders (AlpineSoft)]

This is just a quick note to say that as of V7.5, VinylStudio can both import and export mono files.  Enjoy.