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.