Here's an e-mail I sent Alan today about this problem:
Alan,
Regarding my post on the message board pertaining to subsonic rumble, here's a pic of my Marantz 2285. I've circled what I suspect may be the closest thing the unit has to the rumble filter you've suggested. In case the photo is not detailed enough, there are two filter buttons: one marked 30Hz, the other 9Khz. Below the two buttons, the marking reads "18db/OCT". Sure enough, the 30Hz filter assists greatly in taming the problem, but it doesn't eliminate it completely. I think I may simply stick with my decidedly low-tech placemat solution. Thanks for your help, sir, and for easing my mind, as well (watching those woofers flap made me feel quite uneasy, as you might imagine). Cheers!
Dave.
