[PAR_WIG1350]

When I was a Freshman someone on my team half jokingly said it would be cool to have a noise canceling system on a robot cart.

But back to the issue at hand, If a sound system is desired for demonstration purposes, It could be designed as part of a modular system. At competitions the sound system could simply be lifted out and replaced with a box to hold some basic tools, A battery holder, and/or an off-board compressor, just to name a few possible options. That way you won't have to push around the dead weight of a sound system that you can't even use at competitions, and you will have a place to put things that you might actually need.