I was playing with speaker levels last night for no good reason and then re-ran the db calibration in my Denon to adjust them back to proper levels. I noticed that when the sub test tone was playing, the sound level constantly seemed to fluctuate. It wasn't in a sin wave type pattern either, it seem to randomly sound louder/quieter every second or two.

I wondered if maybe this was just my hearing or the fact that maybe I wasn't keeping still enough or ?? So I brought out my db meter and had it measuring while I listened. I know the average db meter is not very accurate at LFE frequencies but the changes on the digital reading by +/- up to 2 db did seem to match the fluctuations that my ear was hearing.

Is this a normal effect for subwoofer test tones? I don't recall hearing it before but maybe I just never noticed. Am I just paying more attention or is something a bit wonky?

I have a calibration DVD I can try tones from as well to see if I hear the same thing but I thought I'd ask the experts before I get too far into it.
With great power comes Awesome irresponsibility.