Digital wavering like tape recorder.
 

My setup is a zoom Q8n video recorder. Built in mics turned off and my external mic, Rode nt-4 plugged in. I have one panned left the other panned fully right. levels set with peaks hitting between -12/-6. In a spot or two I have noticed a little wavering sound. Kinda like a tape recorder. What could this be? Room is very quiet. no vents or fans. I can't figure it out. Shouldn't be my recorder. Is this a common problem with mics? If the cable was shorting what would it sound like? Can't try a different cable because the NT-4 comes with a Y split XLR. Any Ideas?

Probably mike shaking - floor movement for example - and/or air movement - breath towards mike for example. Of course a recorded sample of that sound would likely be helpful.

I can't seem to figure out how to post the audio track on here...probably has to be uploaded elsewhere and linked I guess? I did figure out that it is always on my input 1 or the left side of the mic. I need to do some switching around for tests I guess...

Physical (mic shaking) or maybe they're out of phase?

Do you have 2 mics plugged in? If so, then it is most probably a phase issue (one mic further away from the sound source than the other).

Does the system have independent compression on each channel? If it does and you are hitting it with spaced mics with differential levels it could be pumping the compressors at differential rates and giving you both level and L-R imaging anomalies. Might sound a bit like wow or flutter. You'd need to find a way to link the two compressors.

Bob

Well the rode Nt-4 is a single mic with two capsules on the end and a y plug. So it is fixed like two mics in an XY.
The problem is in the straight raw file. no compression or anything added.

That is curious ... Yes try reversing the mic cable leads L for R and see if the waver goes to the right side.

Also if you have track phase or polarity reversal capability in you DAW try it as well ( this may only work if you are going into two mono tracks istead of one stereo track.

If you wish you can email me a short (say up to 30 second) mp3 and I can upload it to my website with a link to it.

I thought I would respond to this for the sake of future archives. Incase someone runs across this topic with the same problem. It seems to correct the problem I just set the sample rate back to 44.1/24 bit. When the "glitches" were happening the sample rate was set on 48. It hasn't happened since setting back to 44.1. weird...

That shouldn't happen with half way decent gear but then again it's a Zoom. I don't know the quality of sample rate conversions made by Zoom or it buffer size setting.