30 lbs shouldn't be a problem, I'm 200lbs and stand on top of my EP500 all the time to change light bulbs above it. Now I'd keep water away from it though, MDF and H20 ain't good bedfellows.

Velo DD18,2xAxiom EP500,2xeD A7-450,2xSVS PB13U,2xSVS SB13P,2xInfinity Kappa12mbm, 2xB&W PCS8