/cgl/ - Cosplay & EGL

I'm planning on making Nonon's Symphony Regalia: Finale, and I'm not quite sure how to do the speakers. I figured it'd require the use of a sturdy harness, but all the harness tutorials that I've seen either are too big or need something on the lower torso to cover it up. How would I make a harness that only requires the top half of the body (so that it would be covered by the half shirt thing she's wearing) and be sturdy enough to balance the two speakers?