3 subwoofers, center sub uses crossover to split frequencies

[olds1959special]

Anyone doing anything like this? I have L/R subwoofers underneath each speaker, but then added a third subwoofer to the center. The center sub does not play as low, and only has single ended inputs, so I hooked it up from the RCA outputs of each subwoofer, after turning down the LPF on the L/R subs to 50 Hz. So now, the L/R subs play 30-50Hz and the center sub plays 50Hz - 80Hz. I'm not sure what the point of this is? It's fun to try out weird things.