I assume with both subs (plus the door speakers) the upper bass region (100-150hz) is going to have a nasty peak. Maybe you like how that sounds but it is just throwing the whole system out of balance. An RTA read out with pink noise would confirm. If you go this route I would run HS10's crossover much lower to reduce the overlap in frequencies to reduce the peak. In theory with proper tuning you could use the HS10 as a true sub-woofer (<60Hz) while the OEM Bose just handles the upper bass.