I recently recorded a live show using a USB connection between a Behringer X32 and a DAW running on a laptop (not Audacity). I’ve done this before and it’s worked fine, but this time my laptop locked up several times. I thought I lost everything … However, when I got home, I found:
All tracks recorded as PCM24LE, but when you play them back the recordings gets progressively faster and higher in pitch (not linear, the changes are at seemingly random intervals) and the track have digital distortion. I think the X32 sent me floating bit files, but my DAW closed the files with a constant PCM CODEC.
I’ve been using Audacity 2.1.0 to import the raw data at various sampling and bit rates, but I can’t get a usable waveform from any of the floating bit formats 32 or 64 bit. I’ve even used Hex Editor NEO to determine the true starting point for the raw data stream and alter the header records to spoof various formats … but nothing has worked.
Unfortunately, the club doesn’t have a full time sound engineer, so they can’t tell me anything about the output of the board.
Has anyone else experienced this problem? Do you have any recovery tips for me?
If you believe the tracks recorded as PCM 24-bit Little Endian that is how you should raw import them.
If you have determined the offset before the data, enter it in Raw Data, or try 0, 1 or 2.
It doesn’t sound like there is much you can do. If only the headers were corrupted then replacing them in a Hex editor and adjusting the offset should get you reasonably close.
Thanks Gale, I think my DAW closed the file and set up the header as PCM24LE, but when open (or raw import) with those settings I still get digital distortion and the pit speed changes. It makes me think that that’s not the right format.
I’ve uploaded a small extract as an example.
The track was imported at 48000 PCM24LE. It starts fine but in this 30sec it changes speed/pitch 3 times indicating to me that it’s not a fixed bit rate recording … NOTE: The original data stream sounds fine (this extract was reduced to 8-bit to reduce the file size).
Have you ever encountered this situation?
Do you know of any tools that will analyze the raw data stream to determine the correct playback format?
Get the MediaInfo version without installer, because the installer may have malware or adware.
PCM formats don’t do variable bit rate. It would seem to me the data is now actually speed-stepped and you will have to go through the sections using Change Speed by ear. For example, -16% at the first speed change in your file works.
… Thanks Gale, you’ve been very helpful.