Are you sure 611a would be enough? I'm not an expert, but what I've researched so far is: 2 infinity subs are 350 RMS @ 4ohm double voice coil, and it either can be connected @ 1 Ohm, or @ 4 Ohm. Very little amps are 1Ohm stable, and 4 Ohm is more recommended. And 611a is 456 RMS @ 4 Ohm. Subs are 700 RMS together. Am I right on this one? If not please explain.