Hi,
Randyman is correct. Set the receiver's sub output level to no more than the mid-way setting and the subwoofer gain somewhere between the 9 o'clock and 12 o'clock position. Most input and output levels are more or less standardized to keep distortion at residual levels when you set up the controls as I've described. If you set the receiver sub out level as low as you mentioned, the signal-to-noise on the sub signal would be lousy because the signal would be just above the noise floor of the receiver's subwoofer output preamp.
Regards,
