So I noticed this noise (the low end rumble not the freezer noise in the background) every now and then, but it's been really bad lately. Judging by the wave form it looks like it's coming either directly from the mic or in the pre, maybe a loose connection? I'm in a basement in a quiet neighborhood with floating floor and minimal acoustic treatment (essentially just bass traps). I moved the mic around with no luck. Can anybody tell from the sound what type of problem I might be faxing here?