I'm having a problem with my rack (a good 50 pounds in an 8-space rack) sliding around on top of my 2X10 cabinet.  The rack does have rubber feet, but it doesn't seem to matter when I hit certain notes on the E or B-string (varies per instrument).  The other night, the rack slid right off the front.  Luckily I was standing in front of it, so there was no damage except to the back of my knee.  Are there any products out there, or makeshift remedies?

Jerry,
I use small pieces of Velcro to hold in place small boxes. Strategic pieces could be just enough to stop some of these issues. It defiantly won't hold 50 lbs from falling but might be enough for what trying to do which stop some of the effects of vibration. Also removable.
Pete

How about a foam pad? I've been hearing vibrations from my racks lately and been thinking about doing something like that to isolate my rack from the speakers.
 
Keith

I have been using a 1 thick, high density foam slab under my rack for years. I also have an 8 space rack, and it doesn't move at all. It also eliminates any vibration.  
 
Regards,
Pete

A folded towel or blanket can also be effective.  But my preference has been to set the rack on a milk crate or other sturdy stand next to the speaker cab(s).  This helps eliminate any problems that cabinet vibration can cause to rack components.  The milk crate or similar box can do double duty as something to carry things in for load-in and load-out.

Auralex Subdude

I use two pieces of camping mat (high density foam) folded and taped which stops anything sliding around and also damps most of the vibrations from the cabinets so there aren't any rattles coming from the rack. You can just about make them out in this pic..

 
They fit nicely into the rear rack cover when I pack it all away.
 
Graeme

Here's Phil's rig from a recent performance on May 24:
 

 
Unfortunately, it appears to be at least a 2-man job to place that rack on top of that road case - !
 
Wherever possible, I place any amps, rack gear, etc. to the side of the speakers. I believe that exposing delicate electronic equipment to additional vibration for extended periods of time is potentially detrimental to its performance.

Now I want to know what?s on Phil?s rack... specially what is that laptop on the sliding table for.

Guys, thanks so much for the suggestions.  I should have my hands on a piece of 1 HD foam in the next day or two.  I will see how that works.  I already have an Auralex Gamma that I use under my cab to de-couple it from the floor.  I'm not sure how well it would work between the rack and the cabinet, though.  Also, I agree that optimally I would want to separate the two completely.  I will have to think about that and maybe try it at a gig to see how it goes.  Thanks again.

Re: Phil's laptop - dooood - how else you think he keeps up wit his Facebook posse during gigs - yo?
 
 
Seriously - I was in the front row for this performance and watched him use it dial in his tone. It appeared that it retained some past settings that he then further tweaked to his preference immediately prior to starting the gig. He waited until the room was filled with people - smart guy.
 
People are like giant pillows - they absorb sound waves.
 
I'm guessing that he knows this and used the laptop to assist him with making the appropriate adjustments.

David ___ How about an RTA ( real time analyzer) program on the laptop ? Were there any calibration microphones that you could see ?  
 
 Wolf

Perhaps the laptop is used to tune his Meyer powered cabinets to room dynamics per venue?

Perhaps the Meyer Sound  System Integration Tools
 
http://www.meyersound.com/products/compass_rms/
 
http://www.meyersound.com/products/mapponline/pro/
 
http://www.meyersound.com/products/sim/sim3/

Wow..... just Wow. When you thought you had it all figured out regarding High quality sound on stage...