I have no idea if I spelled that right .

I've got a HK 630 amp section powering my subs. I know it's underpowered but for my little room works very well, much better in fact than both a 90's 70wpc Pioneer PL rec'r or a pair of 80 wpc plates.

Anyway, under louder play I've noticed a "voooom" sound that goes left to right, obviously from the subs (they're in the left & right corners, and with the drivers facing downward with the top of the magnet assemblies about 10" from the ceiling it's clear where it's coming from).

So like this, regular as far as I can tell: vooooom ........ vooooom ......... vooooom........ and so on. Not very loud, kinda "under" the music, but audible to my ear. The SO can't hear it, but like she'd tell you, she doesn't care, either . If it was louder you could probably use the sound in some type of rave/rap stuff lol.

Is this oscillating? Could is be some wierd room problem? Any ideas?

Thanks!

Pete