Replaced my home theater’s subwoofer

My Infinity TSS-SUB750 subwoofer started having problems with hum and high pitch noise. The noise was getting worse and distracting so I replaced the speaker. Infinity doesn’t sell home theater speakers anymore. Instead, I bought Infinity’s REFERENCE SUB R10 which was similar in size and wattage. The R10 has a low-frequency effects (LFE) crossover setting, but it seems to have too much midrange. I’m using the LFE setting because my receiver has it.

Infinity subwoofer
REFERENCE SUB R10
Infinity subwoofer
REFERENCE SUB R10