Topic: What is the deal with this wave form?

[hoyt]

It sounds like the left channel (on the top), goes in and out, then in and out.  It's just a basic mboh 603/ka200n > 722 recording, still at 24 bit too.

http://download.yousendit.com/7CCB0FA725619099

Thanks for taking a look (and listen)!

--hoyt

EDIT: This went into the wrong forum, oops

[bluegrass_brad]

That's phase shift.  Was it windy or were you stealthing?

[hoyt]

That's phase shift.  Was it windy or were you stealthing?

Nope, indoors at a small acoustic cafe running DINa at about 6 feet.  Would someone stepping infront of one channel cause that?  Thanks!

--hoyt

[bluegrass_brad]

Im not sure about that.  Although it looks to me as if both channels have it. Was there a ventilation system or a ceiling fan?
edited to add:
Does the whole wave form look like this or just this section of it?

[cleantone]

Did you use shockmounts? It is sort of like what wind will do but very abrupt. If there is wind moving your diaphram to extremes you will lose the high end detail. That is happening here. But it is so abrupt it might have been bumped or something for that half second. Was there more instances or just this? There is obviously a jump in amplitude and it is all low end. Someone stepping in front of your left mic would cut the high end but not bump all that low end at the same time.

[hoyt]

Im not sure about that.  Although it looks to me as if both channels have it. Was there a ventilation system or a ceiling fan?
edited to add:
Does the whole wave form look like this or just this section of it?

I'm pretty sure it's just this section, but I haven't looked over the whole show at this level yet.  I just heard it when playing back today and it caught my attention.  I don't think there was a fan above my mics, but I don't remember specifically checking. 

Did you use shockmounts? It is sort of like what wind will do but very abrupt. If there is wind moving your diaphram to extremes you will lose the high end detail. That is happening here. But it is so abrupt it might have been bumped or something for that half second. Was there more instances or just this? There is obviously a jump in amplitude and it is all low end. Someone stepping in front of your left mic would cut the high end but not bump all that low end at the same time.

Yup, I had shockmounts.  It's possile the stand got bumped, but wouldn't that effect both channels pretty equally?

Thanks!

--hoyt

EDIT:  Oops, I was thinking of the wrong show.  Yes, I was under ventilation at this show.  I had my mics suspended over a balcony actually.  For this one the mics were AB, so I would think that both channels would reflect any phase shifting caused by wind.

[bluegrass_brad]

EDIT:  Oops, I was thinking of the wrong show.  Yes, I was under ventilation at this show.  I had my mics suspended over a balcony actually.  For this one the mics were AB, so I would think that both channels would reflect any phase shifting caused by wind.

They do.  Look closer, they are both suffering from phase shift.  The left just has a more noticible spot in that section.

[hoyt]

They do.  Look closer, they are both suffering from phase shift.  The left just has a more noticible spot in that section.

Ok, I can see that if I look at where the top channel crosses the axis, I can see similar movement in the other channel.  I won't worry too much about it then, the sound of such a sudden drop out in the one channel freaked me out a bit.    Thanks!  +t's to you guys!

--hoyt