I've got a Roland keyboard amp that I use to play backing tracks through.  I like it because it has muscle and it will go really, really deep and create a very realistic drum and bass background.  Okay, so, I stack my guitar amp on top of this keyboard amp.  The problem comes from the keyboard amp causing my guitar amp to rattle which causes all sorts of horrible noises.  I can easily separate both amps but I lack space.  Is there a way I can stack one on top of the other and keep one amp from affecting the other?  Maybe a shelf of some kind or maybe some foam between the two amps.  Whatever it is, I need it to be not too ugly to look at because this is in my living room.  Yeah, I like to jam in my living room.

Any doable ideas?