Topic: Zoom H2 Transfer/file format question

[Lunchbox16]

I hope I'm just over looking something obvious, but here's my current dilemma. Recently I got a live recording of a band in the mail. The taper didn't know how to get the show edited and uploaded online so I told him that I would do it for him. He sent me the show in 2 large FLAC files. According to his recording notes he recorded them at 24bit/96khz using a Zoom H2. Before he sent them, I told him to generate MD5 checksums for the original WAV files so that when I got the FLACs and decoded them I could double check to make sure there weren't any discrepancies. So I loaded the FLAC files onto my computer, decoded them, ran the checksum, and both files failed. I opened the decoded WAV files with Audacity and they showed up as 32 bit float/96khz. I have no idea what 32-bit float is, so I tried to downsample to 24bit, save it, and run the checksum again, hoping that would resolve the issue, but it did not. I verified the original FLAC files in xACT and they came back fine. Is there a setting that I'm totally overlooking here? I know the original taper uses a Mac and used xACT to encode the FLACs and generate the MD5, and I'm using the same platform/software. The FLAC files are 1.18 and 1.14 GB, respectively, so it shouldn't be an issue of file size. I don't understand why there's a problem, and I especially don't understand why the WAV files are reading as 32 bit, when they should be 24bit. Does this make sense? Ideas? Suggestions?

[rjp]

Audacity's native format for editing is 32-bit floating point (i.e. values are stored with a fractional component rather than as integers). Loading any type of file into Audacity will, by default, be put into 32-bit float format inside the editor. You can change that, but IMO it's better to use 32-bit float for editing.

Note that you can load FLACs directly into Audacity, bypassing the decode-to-WAV stage.

[Lunchbox16]

RJP,

  Thanks for the help. I did not know that about Audacity. I wanted to make 2 versions of the show, a 24bit and a 16bit. Once I finish editing the show how do I ensure that the audio quality is preserved? Will a normal "save as wav" keep everything in 24bit, or will Audacity dither the files? I know I'll have to dither for the 16bit, but I just want to make sure I don't lose anything for the 24bit version. Does that make sense?

[rjp]

I wanted to make 2 versions of the show, a 24bit and a 16bit. Once I finish editing the show how do I ensure that the audio quality is preserved?

You can choose dithering settings in the preferences (Edit->Preferences->Quality). Audacity will automatically dither during export for both the 16-bit and 24-bit versions.

The project file will keep its 32-bit float audio format when you save it - dithering only occurs on export to a lower bit depth.

You can also export to FLAC (which will save disk space vs. WAV). I normally export to FLAC and then use Foobar2000 to add tags to the FLAC files. If available, I'll use metaflac (a command-line program) to add cover art such as a scan of the program cover.