Actually the quote from the owners manual of my new head is "We recommend you avoid putting it directly on top of your bass speakers." So where else am I supposed to put it? I mean I realize that the vibration is probably bad for the head in the long run but I'm kind of at a loss on where to put it - I can't think of anywhere except on the cab I've seen most bassists put their amps. Any recommendations? Do I need to go find some kind of rack stand to hold it at a reasonable height but not on the cabs? Life was easier with a combo.