I mean I can't say my head didn't move at all, but it moved as much as other shows and this didn't happen at all....But there were people walking in front every other minute with bathroom and beer breaks, could that have made thast weird noise??
Yes, it certainly could. Now that you mention it, that's more what I'm hearing than motion of the diaphragms (though they have a similar effect); refraction! People walking in front of a microphone (or just standing there) do absorb/refract a certain amount of sound. Their proximity to the microphone (closer), their mass (larger), and distance from the sound source (farther) determine the severity of the effect. In other words: if they're close to the mic, morbidly obese, and far from the source, they will ruin your recording!
I think you may have solved your own mystery. But the only cure I know for the "people proximity" effect is a clear line-of-sight to the sound source (tall mic stand, stilts

, etc.)
I have, though, found the effect to be useful in some situations. I once recorded (Tascam 488 & Sony MS907) a jazz trio at a local restaurant (formerly a clothing store - go figure). The place had display windows with a ~8" rise on either side. It was a long, narrow room. We set up the drum kit in one of the display windows for the particular reverb that it imparted. I put the bassist was on the left (Ampeg B12 near the side wall) and guitarist on the right (Fender 2x12). I put the mic about 10' back and with the snare just off-center (to make a pocket for the vocalist). Their drummer was heavy-handed but refused to use brushes (

) so I had the guitarist stand in front of the kit to stifle the attack a little. It worked.

The recording sounded good (for being made with the MS907) but the group disbanded the week after I made the recording. Then they flaked out on my pay.
