Unexplained Thumps Link to example

[stephenn39712213]

Here is a link (I think) to an example of one of the thumps in my recordings I talked about in my previous question.  The thump is right near the beginning.

Thump sample.wav - Google Drive

[SteveG_AudioMasters_]

My problem with this at present is that I can't see any spectral evidence of a thump at all in your file:

If there was any evidence of a thump at the beginning, the section I've ringed in the spectrogram would have turned yellow. I couldn't even hear any sort of a clonk, never mind a thump! Now admittedly I'm having to play this on a laptop at the moment, but the spectral evidence would show one pretty clearly, and it doesn't appear to. What are you listening to this on?

[ryclark]

No audible thump hear either listening on my studio monitors.

[stephenn39712213]

I'm listening with Bose headphones.

Here is another clip.  The thump is in the word "ripe" when I say "over-ripe".

Thump2.wav - Google Drive

[SteveG_AudioMasters_ · Accepted solution]

Try using the Parametric EQ generic hi pass filter on it (there's a preset with this name) and see if it stops. You really don't need any sort of levels at the frequencies that this will take out, with speech.

[stephenn39712213]

I'll give that a try.  Thank you for helping me out.  I just wish I could figure out what is causing this in the first place.  It occurs one to two times for every minute of recording.

[stephenn39712213]

The hi pass filter works perfectly.  I made a few adjustments to the preset levels and it is flawless now with zero loss of quality.  This will be my fix until I find out what the source is.  Thank you so much.

[SteveG_AudioMasters_]

The first thing you should check is the mounting suspension of the mic (the SMR Shock Mount). If that's okay, and the mic cable is also allowed to move freely, then the other thing that can make a difference - especially within a vocal booth - is the effect of somebody moving within a relatively closed air space. That can cause enough local turbulence for a moment to make this sort of LF effect happen. If this is what it turns out to be, then there's no real fix other than the one you're already using.

And it really doesn't matter if you continue to take out the LF with the filter - that's fine as long as whatever is causing it isn't making the diaphragm flutter to the extent of affecting the speech (like a 'plosive' would). Normally, you'd use the filter anyway - it doesn't do any good to let out anything much below about 80Hz with speech, as there's no content there. Different matter with music - I have to go to a lot of trouble keeping erroneous bass/thump noises out of my mic rigs - but there again I can be recording stuff down to about 17Hz. Even with that, I'll take out everything below 10Hz using a HP filter. I seriously wouldn't worry about using it!