Any way to locate clipping?

Hi all,

I did a live recording some months ago using an RME HDSPe MADI card, fed via fiber from a Soundcraft Vi4 console. It’s one piece of fiber cable and I know the cable is 100% good.

For some reason, during the course of a 3-4 hour live recording, I ended up with 10 or so very short static/clipping noises. Each time it happened, they were 0.1s or shorter. The tracks only recorded this way… we never heard it live. Even stranger, it happened first about 2 hours into the event, it went on for a few minutes and never happened again. The Mac Pro it recorded was just about brand new at the time.

First of all, any idea what may have caused these, and In any case, are there any sort of analyzer tools to find and identify these to make sure I don’t miss any? I need to go back and patch the audio or something to fix these. I don’t think these actually clip… the statistics function in Sample Editor shows them to peak at -0.10dB. Oddly, the DC Offset is 100%.

Also, these are really easy to miss because they are so short, I don’t see any peaks in the waveform views unless I zoom WAY in.

Thanks!

See the below for what this looks like in Sample Editor.

Yuk…looks nasty.

To find them couldn’t you set a hitpoint threshold just below that level…I’m assuming your wanted audio isn’t peaking that high so they’ll hopefully be the only thing detected.

Then you could add markers at hitpoints or create regions or whatever suits you.

Could use something like RX3 to eliminate the DC offset for those sections.

Why they occur? Twilight Zone moments!

As for finding them, perhaps set hitpoints with high threshold.