You will need to add an amplifier to drive the subwoofer. How much power depends on the particular subwoofer. The power rating of the original HTS won't be much help since they tend to exaggerate the power to an extreme.
You will need to add an amplifier to drive the subwoofer. How much power depends on the particular subwoofer. The power rating of the original HTS won't be much help since they tend to exaggerate the power to an extreme.